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kernel-bfs
2.6.30-sched-bfs-209.patch
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File 2.6.30-sched-bfs-209.patch of Package kernel-bfs
The Brain Fuck Scheduler v0.209 by Con Kolivas. A single shared runqueue O(n) strict fairness earliest deadline first design. Ultra low latency and excellent desktop performance. Not recommended for 4096 cpus. Scalability is optimal when your workload is equal to the number of CPUs on bfs. ie you should ONLY do make -j4 on quad core, -j2 on dual core and so on. It's actually faster than higher numbers of jobs on *any* scheduler. Features SCHED_IDLEPRIO and SCHED_ISO scheduling policies as well. To run something idleprio, use schedtool like so: schedtool -D -e make -j4 To run something isoprio, use schedtool like so: schedtool -I -e amarok --- Documentation/sysctl/kernel.txt | 25 fs/pipe.c | 4 fs/proc/base.c | 2 include/linux/init_task.h | 15 include/linux/ioprio.h | 2 include/linux/sched.h | 193 init/Kconfig | 61 kernel/Makefile | 4 kernel/delayacct.c | 2 kernel/exit.c | 6 kernel/fork.c | 2 kernel/kthread.c | 4 kernel/posix-cpu-timers.c | 12 kernel/sched.c |10241 ---------------------------------------- kernel/sched_bfs.c | 5793 ++++++++++++++++++++++ kernel/sched_debug.c | 509 - kernel/sched_fair.c | 1835 ------- kernel/sched_idletask.c | 128 kernel/sched_rt.c | 1771 ------ kernel/sysctl.c | 145 kernel/trace/trace.c | 4 kernel/workqueue.c | 2 mm/oom_kill.c | 2 23 files changed, 5896 insertions(+), 14866 deletions(-) Index: linux-2.6.30-bfs/Documentation/sysctl/kernel.txt =================================================================== --- linux-2.6.30-bfs.orig/Documentation/sysctl/kernel.txt 2009-09-03 19:50:51.796053865 +1000 +++ linux-2.6.30-bfs/Documentation/sysctl/kernel.txt 2009-09-03 19:51:10.160055089 +1000 @@ -27,6 +27,7 @@ - domainname - hostname - hotplug +- iso_cpu - java-appletviewer [ binfmt_java, obsolete ] - java-interpreter [ binfmt_java, obsolete ] - kstack_depth_to_print [ X86 only ] @@ -48,6 +49,7 @@ - randomize_va_space - real-root-dev ==> Documentation/initrd.txt - reboot-cmd [ SPARC only ] +- rr_interval - rtsig-max - rtsig-nr - sem @@ -170,6 +172,16 @@ ============================================================== +iso_cpu: + +This sets the percentage cpu that the unprivileged SCHED_ISO tasks can +run effectively at realtime priority, averaged over a rolling five +seconds over the -whole- system, meaning all cpus. + +Set to 70 (percent) by default. + +============================================================== + l2cr: (PPC only) This flag controls the L2 cache of G3 processor boards. If @@ -322,6 +334,19 @@ ============================================================== +rr_interval: + +This is the smallest duration that any cpu process scheduling unit +will run for. Increasing this value can increase throughput of cpu +bound tasks substantially but at the expense of increased latencies +overall. This value is in milliseconds and the default value chosen +depends on the number of cpus available at scheduler initialisation +with a minimum of 6. + +Valid values are from 1-5000. + +============================================================== + rtsig-max & rtsig-nr: The file rtsig-max can be used to tune the maximum number Index: linux-2.6.30-bfs/fs/pipe.c =================================================================== --- linux-2.6.30-bfs.orig/fs/pipe.c 2009-09-03 19:50:51.757054464 +1000 +++ linux-2.6.30-bfs/fs/pipe.c 2009-09-03 19:51:10.181054636 +1000 @@ -78,10 +78,6 @@ { DEFINE_WAIT(wait); - /* - * Pipes are system-local resources, so sleeping on them - * is considered a noninteractive wait: - */ prepare_to_wait(&pipe->wait, &wait, TASK_INTERRUPTIBLE); pipe_unlock(pipe); schedule(); Index: linux-2.6.30-bfs/include/linux/init_task.h =================================================================== --- linux-2.6.30-bfs.orig/include/linux/init_task.h 2009-09-03 19:50:51.802053428 +1000 +++ linux-2.6.30-bfs/include/linux/init_task.h 2009-09-06 18:56:46.759601885 +1000 @@ -119,21 +119,16 @@ .usage = ATOMIC_INIT(2), \ .flags = PF_KTHREAD, \ .lock_depth = -1, \ - .prio = MAX_PRIO-20, \ + .prio = NORMAL_PRIO, \ .static_prio = MAX_PRIO-20, \ - .normal_prio = MAX_PRIO-20, \ + .normal_prio = NORMAL_PRIO, \ + .deadline = 0, \ .policy = SCHED_NORMAL, \ .cpus_allowed = CPU_MASK_ALL, \ .mm = NULL, \ .active_mm = &init_mm, \ - .se = { \ - .group_node = LIST_HEAD_INIT(tsk.se.group_node), \ - }, \ - .rt = { \ - .run_list = LIST_HEAD_INIT(tsk.rt.run_list), \ - .time_slice = HZ, \ - .nr_cpus_allowed = NR_CPUS, \ - }, \ + .run_list = LIST_HEAD_INIT(tsk.run_list), \ + .time_slice = HZ, \ .tasks = LIST_HEAD_INIT(tsk.tasks), \ .pushable_tasks = PLIST_NODE_INIT(tsk.pushable_tasks, MAX_PRIO), \ .ptraced = LIST_HEAD_INIT(tsk.ptraced), \ Index: linux-2.6.30-bfs/include/linux/sched.h =================================================================== --- linux-2.6.30-bfs.orig/include/linux/sched.h 2009-09-03 19:50:51.813054751 +1000 +++ linux-2.6.30-bfs/include/linux/sched.h 2009-09-03 23:38:22.267262950 +1000 @@ -36,8 +36,11 @@ #define SCHED_FIFO 1 #define SCHED_RR 2 #define SCHED_BATCH 3 -/* SCHED_ISO: reserved but not implemented yet */ -#define SCHED_IDLE 5 +#define SCHED_ISO 4 +#define SCHED_IDLEPRIO 5 + +#define SCHED_MAX (SCHED_IDLEPRIO) +#define SCHED_RANGE(policy) ((policy) <= SCHED_MAX) #ifdef __KERNEL__ @@ -141,13 +144,10 @@ extern unsigned long get_parent_ip(unsigned long addr); struct seq_file; -struct cfs_rq; struct task_group; #ifdef CONFIG_SCHED_DEBUG extern void proc_sched_show_task(struct task_struct *p, struct seq_file *m); extern void proc_sched_set_task(struct task_struct *p); -extern void -print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq); #else static inline void proc_sched_show_task(struct task_struct *p, struct seq_file *m) @@ -156,10 +156,6 @@ static inline void proc_sched_set_task(struct task_struct *p) { } -static inline void -print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq) -{ -} #endif extern unsigned long long time_sync_thresh; @@ -251,8 +247,8 @@ extern void init_idle(struct task_struct *idle, int cpu); extern void init_idle_bootup_task(struct task_struct *idle); -extern int runqueue_is_locked(void); -extern void task_rq_unlock_wait(struct task_struct *p); +extern int grunqueue_is_locked(void); +extern void grq_unlock_wait(void); extern cpumask_var_t nohz_cpu_mask; #if defined(CONFIG_SMP) && defined(CONFIG_NO_HZ) @@ -969,151 +965,9 @@ struct mempolicy; struct pipe_inode_info; struct uts_namespace; - struct rq; struct sched_domain; -struct sched_class { - const struct sched_class *next; - - void (*enqueue_task) (struct rq *rq, struct task_struct *p, int wakeup); - void (*dequeue_task) (struct rq *rq, struct task_struct *p, int sleep); - void (*yield_task) (struct rq *rq); - - void (*check_preempt_curr) (struct rq *rq, struct task_struct *p, int sync); - - struct task_struct * (*pick_next_task) (struct rq *rq); - void (*put_prev_task) (struct rq *rq, struct task_struct *p); - -#ifdef CONFIG_SMP - int (*select_task_rq)(struct task_struct *p, int sync); - - unsigned long (*load_balance) (struct rq *this_rq, int this_cpu, - struct rq *busiest, unsigned long max_load_move, - struct sched_domain *sd, enum cpu_idle_type idle, - int *all_pinned, int *this_best_prio); - - int (*move_one_task) (struct rq *this_rq, int this_cpu, - struct rq *busiest, struct sched_domain *sd, - enum cpu_idle_type idle); - void (*pre_schedule) (struct rq *this_rq, struct task_struct *task); - int (*needs_post_schedule) (struct rq *this_rq); - void (*post_schedule) (struct rq *this_rq); - void (*task_wake_up) (struct rq *this_rq, struct task_struct *task); - - void (*set_cpus_allowed)(struct task_struct *p, - const struct cpumask *newmask); - - void (*rq_online)(struct rq *rq); - void (*rq_offline)(struct rq *rq); -#endif - - void (*set_curr_task) (struct rq *rq); - void (*task_tick) (struct rq *rq, struct task_struct *p, int queued); - void (*task_new) (struct rq *rq, struct task_struct *p); - - void (*switched_from) (struct rq *this_rq, struct task_struct *task, - int running); - void (*switched_to) (struct rq *this_rq, struct task_struct *task, - int running); - void (*prio_changed) (struct rq *this_rq, struct task_struct *task, - int oldprio, int running); - -#ifdef CONFIG_FAIR_GROUP_SCHED - void (*moved_group) (struct task_struct *p); -#endif -}; - -struct load_weight { - unsigned long weight, inv_weight; -}; - -/* - * CFS stats for a schedulable entity (task, task-group etc) - * - * Current field usage histogram: - * - * 4 se->block_start - * 4 se->run_node - * 4 se->sleep_start - * 6 se->load.weight - */ -struct sched_entity { - struct load_weight load; /* for load-balancing */ - struct rb_node run_node; - struct list_head group_node; - unsigned int on_rq; - - u64 exec_start; - u64 sum_exec_runtime; - u64 vruntime; - u64 prev_sum_exec_runtime; - - u64 last_wakeup; - u64 avg_overlap; - - u64 start_runtime; - u64 avg_wakeup; - u64 nr_migrations; - -#ifdef CONFIG_SCHEDSTATS - u64 wait_start; - u64 wait_max; - u64 wait_count; - u64 wait_sum; - - u64 sleep_start; - u64 sleep_max; - s64 sum_sleep_runtime; - - u64 block_start; - u64 block_max; - u64 exec_max; - u64 slice_max; - - u64 nr_migrations_cold; - u64 nr_failed_migrations_affine; - u64 nr_failed_migrations_running; - u64 nr_failed_migrations_hot; - u64 nr_forced_migrations; - u64 nr_forced2_migrations; - - u64 nr_wakeups; - u64 nr_wakeups_sync; - u64 nr_wakeups_migrate; - u64 nr_wakeups_local; - u64 nr_wakeups_remote; - u64 nr_wakeups_affine; - u64 nr_wakeups_affine_attempts; - u64 nr_wakeups_passive; - u64 nr_wakeups_idle; -#endif - -#ifdef CONFIG_FAIR_GROUP_SCHED - struct sched_entity *parent; - /* rq on which this entity is (to be) queued: */ - struct cfs_rq *cfs_rq; - /* rq "owned" by this entity/group: */ - struct cfs_rq *my_q; -#endif -}; - -struct sched_rt_entity { - struct list_head run_list; - unsigned long timeout; - unsigned int time_slice; - int nr_cpus_allowed; - - struct sched_rt_entity *back; -#ifdef CONFIG_RT_GROUP_SCHED - struct sched_rt_entity *parent; - /* rq on which this entity is (to be) queued: */ - struct rt_rq *rt_rq; - /* rq "owned" by this entity/group: */ - struct rt_rq *my_q; -#endif -}; - struct task_struct { volatile long state; /* -1 unrunnable, 0 runnable, >0 stopped */ void *stack; @@ -1123,17 +977,18 @@ int lock_depth; /* BKL lock depth */ -#ifdef CONFIG_SMP -#ifdef __ARCH_WANT_UNLOCKED_CTXSW int oncpu; -#endif -#endif - + int load_weight; /* for niceness load balancing purposes */ int prio, static_prio, normal_prio; + int time_slice, first_time_slice; + unsigned long deadline; + struct list_head run_list; unsigned int rt_priority; - const struct sched_class *sched_class; - struct sched_entity se; - struct sched_rt_entity rt; + unsigned long long timestamp, last_ran; + u64 sched_time; /* sched_clock time spent running */ + + int rt_nr_cpus_allowed; + unsigned long rt_timeout; #ifdef CONFIG_PREEMPT_NOTIFIERS /* list of struct preempt_notifier: */ @@ -1156,6 +1011,9 @@ unsigned int policy; cpumask_t cpus_allowed; +#ifdef CONFIG_HOTPLUG_CPU + cpumask_t unplugged_mask; +#endif #ifdef CONFIG_PREEMPT_RCU int rcu_read_lock_nesting; @@ -1446,11 +1304,14 @@ * priority to a value higher than any user task. Note: * MAX_RT_PRIO must not be smaller than MAX_USER_RT_PRIO. */ - +#define PRIO_RANGE (40) #define MAX_USER_RT_PRIO 100 #define MAX_RT_PRIO MAX_USER_RT_PRIO - -#define MAX_PRIO (MAX_RT_PRIO + 40) +#define MAX_PRIO (MAX_RT_PRIO + PRIO_RANGE) +#define ISO_PRIO (MAX_RT_PRIO) +#define NORMAL_PRIO (MAX_RT_PRIO + 1) +#define IDLE_PRIO (MAX_RT_PRIO + 2) +#define PRIO_LIMIT ((IDLE_PRIO) + 1) #define DEFAULT_PRIO (MAX_RT_PRIO + 20) static inline int rt_prio(int prio) @@ -1733,11 +1594,7 @@ extern unsigned long long thread_group_sched_runtime(struct task_struct *task); /* sched_exec is called by processes performing an exec */ -#ifdef CONFIG_SMP -extern void sched_exec(void); -#else #define sched_exec() {} -#endif extern void sched_clock_idle_sleep_event(void); extern void sched_clock_idle_wakeup_event(u64 delta_ns); Index: linux-2.6.30-bfs/kernel/sched.c =================================================================== --- linux-2.6.30-bfs.orig/kernel/sched.c 2009-09-03 19:50:51.846053376 +1000 +++ /dev/null 1970-01-01 00:00:00.000000000 +0000 @@ -1,10241 +0,0 @@ -/* - * kernel/sched.c - * - * Kernel scheduler and related syscalls - * - * Copyright (C) 1991-2002 Linus Torvalds - * - * 1996-12-23 Modified by Dave Grothe to fix bugs in semaphores and - * make semaphores SMP safe - * 1998-11-19 Implemented schedule_timeout() and related stuff - * by Andrea Arcangeli - * 2002-01-04 New ultra-scalable O(1) scheduler by Ingo Molnar: - * hybrid priority-list and round-robin design with - * an array-switch method of distributing timeslices - * and per-CPU runqueues. Cleanups and useful suggestions - * by Davide Libenzi, preemptible kernel bits by Robert Love. - * 2003-09-03 Interactivity tuning by Con Kolivas. - * 2004-04-02 Scheduler domains code by Nick Piggin - * 2007-04-15 Work begun on replacing all interactivity tuning with a - * fair scheduling design by Con Kolivas. - * 2007-05-05 Load balancing (smp-nice) and other improvements - * by Peter Williams - * 2007-05-06 Interactivity improvements to CFS by Mike Galbraith - * 2007-07-01 Group scheduling enhancements by Srivatsa Vaddagiri - * 2007-11-29 RT balancing improvements by Steven Rostedt, Gregory Haskins, - * Thomas Gleixner, Mike Kravetz - */ - -#include <linux/mm.h> -#include <linux/module.h> -#include <linux/nmi.h> -#include <linux/init.h> -#include <linux/uaccess.h> -#include <linux/highmem.h> -#include <linux/smp_lock.h> -#include <asm/mmu_context.h> -#include <linux/interrupt.h> -#include <linux/capability.h> -#include <linux/completion.h> -#include <linux/kernel_stat.h> -#include <linux/debug_locks.h> -#include <linux/security.h> -#include <linux/notifier.h> -#include <linux/profile.h> -#include <linux/freezer.h> -#include <linux/vmalloc.h> -#include <linux/blkdev.h> -#include <linux/delay.h> -#include <linux/pid_namespace.h> -#include <linux/smp.h> -#include <linux/threads.h> -#include <linux/timer.h> -#include <linux/rcupdate.h> -#include <linux/cpu.h> -#include <linux/cpuset.h> -#include <linux/percpu.h> -#include <linux/kthread.h> -#include <linux/proc_fs.h> -#include <linux/seq_file.h> -#include <linux/sysctl.h> -#include <linux/syscalls.h> -#include <linux/times.h> -#include <linux/tsacct_kern.h> -#include <linux/kprobes.h> -#include <linux/delayacct.h> -#include <linux/reciprocal_div.h> -#include <linux/unistd.h> -#include <linux/pagemap.h> -#include <linux/hrtimer.h> -#include <linux/tick.h> -#include <linux/bootmem.h> -#include <linux/debugfs.h> -#include <linux/ctype.h> -#include <linux/ftrace.h> -#include <trace/sched.h> - -#include <asm/tlb.h> -#include <asm/irq_regs.h> - -#include "sched_cpupri.h" - -/* - * Convert user-nice values [ -20 ... 0 ... 19 ] - * to static priority [ MAX_RT_PRIO..MAX_PRIO-1 ], - * and back. - */ -#define NICE_TO_PRIO(nice) (MAX_RT_PRIO + (nice) + 20) -#define PRIO_TO_NICE(prio) ((prio) - MAX_RT_PRIO - 20) -#define TASK_NICE(p) PRIO_TO_NICE((p)->static_prio) - -/* - * 'User priority' is the nice value converted to something we - * can work with better when scaling various scheduler parameters, - * it's a [ 0 ... 39 ] range. - */ -#define USER_PRIO(p) ((p)-MAX_RT_PRIO) -#define TASK_USER_PRIO(p) USER_PRIO((p)->static_prio) -#define MAX_USER_PRIO (USER_PRIO(MAX_PRIO)) - -/* - * Helpers for converting nanosecond timing to jiffy resolution - */ -#define NS_TO_JIFFIES(TIME) ((unsigned long)(TIME) / (NSEC_PER_SEC / HZ)) - -#define NICE_0_LOAD SCHED_LOAD_SCALE -#define NICE_0_SHIFT SCHED_LOAD_SHIFT - -/* - * These are the 'tuning knobs' of the scheduler: - * - * default timeslice is 100 msecs (used only for SCHED_RR tasks). - * Timeslices get refilled after they expire. - */ -#define DEF_TIMESLICE (100 * HZ / 1000) - -/* - * single value that denotes runtime == period, ie unlimited time. - */ -#define RUNTIME_INF ((u64)~0ULL) - -DEFINE_TRACE(sched_wait_task); -DEFINE_TRACE(sched_wakeup); -DEFINE_TRACE(sched_wakeup_new); -DEFINE_TRACE(sched_switch); -DEFINE_TRACE(sched_migrate_task); - -#ifdef CONFIG_SMP - -static void double_rq_lock(struct rq *rq1, struct rq *rq2); - -/* - * Divide a load by a sched group cpu_power : (load / sg->__cpu_power) - * Since cpu_power is a 'constant', we can use a reciprocal divide. - */ -static inline u32 sg_div_cpu_power(const struct sched_group *sg, u32 load) -{ - return reciprocal_divide(load, sg->reciprocal_cpu_power); -} - -/* - * Each time a sched group cpu_power is changed, - * we must compute its reciprocal value - */ -static inline void sg_inc_cpu_power(struct sched_group *sg, u32 val) -{ - sg->__cpu_power += val; - sg->reciprocal_cpu_power = reciprocal_value(sg->__cpu_power); -} -#endif - -static inline int rt_policy(int policy) -{ - if (unlikely(policy == SCHED_FIFO || policy == SCHED_RR)) - return 1; - return 0; -} - -static inline int task_has_rt_policy(struct task_struct *p) -{ - return rt_policy(p->policy); -} - -/* - * This is the priority-queue data structure of the RT scheduling class: - */ -struct rt_prio_array { - DECLARE_BITMAP(bitmap, MAX_RT_PRIO+1); /* include 1 bit for delimiter */ - struct list_head queue[MAX_RT_PRIO]; -}; - -struct rt_bandwidth { - /* nests inside the rq lock: */ - spinlock_t rt_runtime_lock; - ktime_t rt_period; - u64 rt_runtime; - struct hrtimer rt_period_timer; -}; - -static struct rt_bandwidth def_rt_bandwidth; - -static int do_sched_rt_period_timer(struct rt_bandwidth *rt_b, int overrun); - -static enum hrtimer_restart sched_rt_period_timer(struct hrtimer *timer) -{ - struct rt_bandwidth *rt_b = - container_of(timer, struct rt_bandwidth, rt_period_timer); - ktime_t now; - int overrun; - int idle = 0; - - for (;;) { - now = hrtimer_cb_get_time(timer); - overrun = hrtimer_forward(timer, now, rt_b->rt_period); - - if (!overrun) - break; - - idle = do_sched_rt_period_timer(rt_b, overrun); - } - - return idle ? HRTIMER_NORESTART : HRTIMER_RESTART; -} - -static -void init_rt_bandwidth(struct rt_bandwidth *rt_b, u64 period, u64 runtime) -{ - rt_b->rt_period = ns_to_ktime(period); - rt_b->rt_runtime = runtime; - - spin_lock_init(&rt_b->rt_runtime_lock); - - hrtimer_init(&rt_b->rt_period_timer, - CLOCK_MONOTONIC, HRTIMER_MODE_REL); - rt_b->rt_period_timer.function = sched_rt_period_timer; -} - -static inline int rt_bandwidth_enabled(void) -{ - return sysctl_sched_rt_runtime >= 0; -} - -static void start_rt_bandwidth(struct rt_bandwidth *rt_b) -{ - ktime_t now; - - if (!rt_bandwidth_enabled() || rt_b->rt_runtime == RUNTIME_INF) - return; - - if (hrtimer_active(&rt_b->rt_period_timer)) - return; - - spin_lock(&rt_b->rt_runtime_lock); - for (;;) { - unsigned long delta; - ktime_t soft, hard; - - if (hrtimer_active(&rt_b->rt_period_timer)) - break; - - now = hrtimer_cb_get_time(&rt_b->rt_period_timer); - hrtimer_forward(&rt_b->rt_period_timer, now, rt_b->rt_period); - - soft = hrtimer_get_softexpires(&rt_b->rt_period_timer); - hard = hrtimer_get_expires(&rt_b->rt_period_timer); - delta = ktime_to_ns(ktime_sub(hard, soft)); - __hrtimer_start_range_ns(&rt_b->rt_period_timer, soft, delta, - HRTIMER_MODE_ABS, 0); - } - spin_unlock(&rt_b->rt_runtime_lock); -} - -#ifdef CONFIG_RT_GROUP_SCHED -static void destroy_rt_bandwidth(struct rt_bandwidth *rt_b) -{ - hrtimer_cancel(&rt_b->rt_period_timer); -} -#endif - -/* - * sched_domains_mutex serializes calls to arch_init_sched_domains, - * detach_destroy_domains and partition_sched_domains. - */ -static DEFINE_MUTEX(sched_domains_mutex); - -#ifdef CONFIG_GROUP_SCHED - -#include <linux/cgroup.h> - -struct cfs_rq; - -static LIST_HEAD(task_groups); - -/* task group related information */ -struct task_group { -#ifdef CONFIG_CGROUP_SCHED - struct cgroup_subsys_state css; -#endif - -#ifdef CONFIG_USER_SCHED - uid_t uid; -#endif - -#ifdef CONFIG_FAIR_GROUP_SCHED - /* schedulable entities of this group on each cpu */ - struct sched_entity **se; - /* runqueue "owned" by this group on each cpu */ - struct cfs_rq **cfs_rq; - unsigned long shares; -#endif - -#ifdef CONFIG_RT_GROUP_SCHED - struct sched_rt_entity **rt_se; - struct rt_rq **rt_rq; - - struct rt_bandwidth rt_bandwidth; -#endif - - struct rcu_head rcu; - struct list_head list; - - struct task_group *parent; - struct list_head siblings; - struct list_head children; -}; - -#ifdef CONFIG_USER_SCHED - -/* Helper function to pass uid information to create_sched_user() */ -void set_tg_uid(struct user_struct *user) -{ - user->tg->uid = user->uid; -} - -/* - * Root task group. - * Every UID task group (including init_task_group aka UID-0) will - * be a child to this group. - */ -struct task_group root_task_group; - -#ifdef CONFIG_FAIR_GROUP_SCHED -/* Default task group's sched entity on each cpu */ -static DEFINE_PER_CPU(struct sched_entity, init_sched_entity); -/* Default task group's cfs_rq on each cpu */ -static DEFINE_PER_CPU(struct cfs_rq, init_cfs_rq) ____cacheline_aligned_in_smp; -#endif /* CONFIG_FAIR_GROUP_SCHED */ - -#ifdef CONFIG_RT_GROUP_SCHED -static DEFINE_PER_CPU(struct sched_rt_entity, init_sched_rt_entity); -static DEFINE_PER_CPU(struct rt_rq, init_rt_rq) ____cacheline_aligned_in_smp; -#endif /* CONFIG_RT_GROUP_SCHED */ -#else /* !CONFIG_USER_SCHED */ -#define root_task_group init_task_group -#endif /* CONFIG_USER_SCHED */ - -/* task_group_lock serializes add/remove of task groups and also changes to - * a task group's cpu shares. - */ -static DEFINE_SPINLOCK(task_group_lock); - -#ifdef CONFIG_SMP -static int root_task_group_empty(void) -{ - return list_empty(&root_task_group.children); -} -#endif - -#ifdef CONFIG_FAIR_GROUP_SCHED -#ifdef CONFIG_USER_SCHED -# define INIT_TASK_GROUP_LOAD (2*NICE_0_LOAD) -#else /* !CONFIG_USER_SCHED */ -# define INIT_TASK_GROUP_LOAD NICE_0_LOAD -#endif /* CONFIG_USER_SCHED */ - -/* - * A weight of 0 or 1 can cause arithmetics problems. - * A weight of a cfs_rq is the sum of weights of which entities - * are queued on this cfs_rq, so a weight of a entity should not be - * too large, so as the shares value of a task group. - * (The default weight is 1024 - so there's no practical - * limitation from this.) - */ -#define MIN_SHARES 2 -#define MAX_SHARES (1UL << 18) - -static int init_task_group_load = INIT_TASK_GROUP_LOAD; -#endif - -/* Default task group. - * Every task in system belong to this group at bootup. - */ -struct task_group init_task_group; - -/* return group to which a task belongs */ -static inline struct task_group *task_group(struct task_struct *p) -{ - struct task_group *tg; - -#ifdef CONFIG_USER_SCHED - rcu_read_lock(); - tg = __task_cred(p)->user->tg; - rcu_read_unlock(); -#elif defined(CONFIG_CGROUP_SCHED) - tg = container_of(task_subsys_state(p, cpu_cgroup_subsys_id), - struct task_group, css); -#else - tg = &init_task_group; -#endif - return tg; -} - -/* Change a task's cfs_rq and parent entity if it moves across CPUs/groups */ -static inline void set_task_rq(struct task_struct *p, unsigned int cpu) -{ -#ifdef CONFIG_FAIR_GROUP_SCHED - p->se.cfs_rq = task_group(p)->cfs_rq[cpu]; - p->se.parent = task_group(p)->se[cpu]; -#endif - -#ifdef CONFIG_RT_GROUP_SCHED - p->rt.rt_rq = task_group(p)->rt_rq[cpu]; - p->rt.parent = task_group(p)->rt_se[cpu]; -#endif -} - -#else - -#ifdef CONFIG_SMP -static int root_task_group_empty(void) -{ - return 1; -} -#endif - -static inline void set_task_rq(struct task_struct *p, unsigned int cpu) { } -static inline struct task_group *task_group(struct task_struct *p) -{ - return NULL; -} - -#endif /* CONFIG_GROUP_SCHED */ - -/* CFS-related fields in a runqueue */ -struct cfs_rq { - struct load_weight load; - unsigned long nr_running; - - u64 exec_clock; - u64 min_vruntime; - - struct rb_root tasks_timeline; - struct rb_node *rb_leftmost; - - struct list_head tasks; - struct list_head *balance_iterator; - - /* - * 'curr' points to currently running entity on this cfs_rq. - * It is set to NULL otherwise (i.e when none are currently running). - */ - struct sched_entity *curr, *next, *last; - - unsigned int nr_spread_over; - -#ifdef CONFIG_FAIR_GROUP_SCHED - struct rq *rq; /* cpu runqueue to which this cfs_rq is attached */ - - /* - * leaf cfs_rqs are those that hold tasks (lowest schedulable entity in - * a hierarchy). Non-leaf lrqs hold other higher schedulable entities - * (like users, containers etc.) - * - * leaf_cfs_rq_list ties together list of leaf cfs_rq's in a cpu. This - * list is used during load balance. - */ - struct list_head leaf_cfs_rq_list; - struct task_group *tg; /* group that "owns" this runqueue */ - -#ifdef CONFIG_SMP - /* - * the part of load.weight contributed by tasks - */ - unsigned long task_weight; - - /* - * h_load = weight * f(tg) - * - * Where f(tg) is the recursive weight fraction assigned to - * this group. - */ - unsigned long h_load; - - /* - * this cpu's part of tg->shares - */ - unsigned long shares; - - /* - * load.weight at the time we set shares - */ - unsigned long rq_weight; -#endif -#endif -}; - -/* Real-Time classes' related field in a runqueue: */ -struct rt_rq { - struct rt_prio_array active; - unsigned long rt_nr_running; -#if defined CONFIG_SMP || defined CONFIG_RT_GROUP_SCHED - struct { - int curr; /* highest queued rt task prio */ -#ifdef CONFIG_SMP - int next; /* next highest */ -#endif - } highest_prio; -#endif -#ifdef CONFIG_SMP - unsigned long rt_nr_migratory; - int overloaded; - struct plist_head pushable_tasks; -#endif - int rt_throttled; - u64 rt_time; - u64 rt_runtime; - /* Nests inside the rq lock: */ - spinlock_t rt_runtime_lock; - -#ifdef CONFIG_RT_GROUP_SCHED - unsigned long rt_nr_boosted; - - struct rq *rq; - struct list_head leaf_rt_rq_list; - struct task_group *tg; - struct sched_rt_entity *rt_se; -#endif -}; - -#ifdef CONFIG_SMP - -/* - * We add the notion of a root-domain which will be used to define per-domain - * variables. Each exclusive cpuset essentially defines an island domain by - * fully partitioning the member cpus from any other cpuset. Whenever a new - * exclusive cpuset is created, we also create and attach a new root-domain - * object. - * - */ -struct root_domain { - atomic_t refcount; - cpumask_var_t span; - cpumask_var_t online; - - /* - * The "RT overload" flag: it gets set if a CPU has more than - * one runnable RT task. - */ - cpumask_var_t rto_mask; - atomic_t rto_count; -#ifdef CONFIG_SMP - struct cpupri cpupri; -#endif -#if defined(CONFIG_SCHED_MC) || defined(CONFIG_SCHED_SMT) - /* - * Preferred wake up cpu nominated by sched_mc balance that will be - * used when most cpus are idle in the system indicating overall very - * low system utilisation. Triggered at POWERSAVINGS_BALANCE_WAKEUP(2) - */ - unsigned int sched_mc_preferred_wakeup_cpu; -#endif -}; - -/* - * By default the system creates a single root-domain with all cpus as - * members (mimicking the global state we have today). - */ -static struct root_domain def_root_domain; - -#endif - -/* - * This is the main, per-CPU runqueue data structure. - * - * Locking rule: those places that want to lock multiple runqueues - * (such as the load balancing or the thread migration code), lock - * acquire operations must be ordered by ascending &runqueue. - */ -struct rq { - /* runqueue lock: */ - spinlock_t lock; - - /* - * nr_running and cpu_load should be in the same cacheline because - * remote CPUs use both these fields when doing load calculation. - */ - unsigned long nr_running; - #define CPU_LOAD_IDX_MAX 5 - unsigned long cpu_load[CPU_LOAD_IDX_MAX]; -#ifdef CONFIG_NO_HZ - unsigned long last_tick_seen; - unsigned char in_nohz_recently; -#endif - /* capture load from *all* tasks on this cpu: */ - struct load_weight load; - unsigned long nr_load_updates; - u64 nr_switches; - - struct cfs_rq cfs; - struct rt_rq rt; - -#ifdef CONFIG_FAIR_GROUP_SCHED - /* list of leaf cfs_rq on this cpu: */ - struct list_head leaf_cfs_rq_list; -#endif -#ifdef CONFIG_RT_GROUP_SCHED - struct list_head leaf_rt_rq_list; -#endif - - /* - * This is part of a global counter where only the total sum - * over all CPUs matters. A task can increase this counter on - * one CPU and if it got migrated afterwards it may decrease - * it on another CPU. Always updated under the runqueue lock: - */ - unsigned long nr_uninterruptible; - - struct task_struct *curr, *idle; - unsigned long next_balance; - struct mm_struct *prev_mm; - - u64 clock; - - atomic_t nr_iowait; - -#ifdef CONFIG_SMP - struct root_domain *rd; - struct sched_domain *sd; - - unsigned char idle_at_tick; - /* For active balancing */ - int active_balance; - int push_cpu; - /* cpu of this runqueue: */ - int cpu; - int online; - - unsigned long avg_load_per_task; - - struct task_struct *migration_thread; - struct list_head migration_queue; -#endif - -#ifdef CONFIG_SCHED_HRTICK -#ifdef CONFIG_SMP - int hrtick_csd_pending; - struct call_single_data hrtick_csd; -#endif - struct hrtimer hrtick_timer; -#endif - -#ifdef CONFIG_SCHEDSTATS - /* latency stats */ - struct sched_info rq_sched_info; - unsigned long long rq_cpu_time; - /* could above be rq->cfs_rq.exec_clock + rq->rt_rq.rt_runtime ? */ - - /* sys_sched_yield() stats */ - unsigned int yld_count; - - /* schedule() stats */ - unsigned int sched_switch; - unsigned int sched_count; - unsigned int sched_goidle; - - /* try_to_wake_up() stats */ - unsigned int ttwu_count; - unsigned int ttwu_local; - - /* BKL stats */ - unsigned int bkl_count; -#endif -}; - -static DEFINE_PER_CPU_SHARED_ALIGNED(struct rq, runqueues); - -static inline void check_preempt_curr(struct rq *rq, struct task_struct *p, int sync) -{ - rq->curr->sched_class->check_preempt_curr(rq, p, sync); -} - -static inline int cpu_of(struct rq *rq) -{ -#ifdef CONFIG_SMP - return rq->cpu; -#else - return 0; -#endif -} - -/* - * The domain tree (rq->sd) is protected by RCU's quiescent state transition. - * See detach_destroy_domains: synchronize_sched for details. - * - * The domain tree of any CPU may only be accessed from within - * preempt-disabled sections. - */ -#define for_each_domain(cpu, __sd) \ - for (__sd = rcu_dereference(cpu_rq(cpu)->sd); __sd; __sd = __sd->parent) - -#define cpu_rq(cpu) (&per_cpu(runqueues, (cpu))) -#define this_rq() (&__get_cpu_var(runqueues)) -#define task_rq(p) cpu_rq(task_cpu(p)) -#define cpu_curr(cpu) (cpu_rq(cpu)->curr) - -static inline void update_rq_clock(struct rq *rq) -{ - rq->clock = sched_clock_cpu(cpu_of(rq)); -} - -/* - * Tunables that become constants when CONFIG_SCHED_DEBUG is off: - */ -#ifdef CONFIG_SCHED_DEBUG -# define const_debug __read_mostly -#else -# define const_debug static const -#endif - -/** - * runqueue_is_locked - * - * Returns true if the current cpu runqueue is locked. - * This interface allows printk to be called with the runqueue lock - * held and know whether or not it is OK to wake up the klogd. - */ -int runqueue_is_locked(void) -{ - int cpu = get_cpu(); - struct rq *rq = cpu_rq(cpu); - int ret; - - ret = spin_is_locked(&rq->lock); - put_cpu(); - return ret; -} - -/* - * Debugging: various feature bits - */ - -#define SCHED_FEAT(name, enabled) \ - __SCHED_FEAT_##name , - -enum { -#include "sched_features.h" -}; - -#undef SCHED_FEAT - -#define SCHED_FEAT(name, enabled) \ - (1UL << __SCHED_FEAT_##name) * enabled | - -const_debug unsigned int sysctl_sched_features = -#include "sched_features.h" - 0; - -#undef SCHED_FEAT - -#ifdef CONFIG_SCHED_DEBUG -#define SCHED_FEAT(name, enabled) \ - #name , - -static __read_mostly char *sched_feat_names[] = { -#include "sched_features.h" - NULL -}; - -#undef SCHED_FEAT - -static int sched_feat_show(struct seq_file *m, void *v) -{ - int i; - - for (i = 0; sched_feat_names[i]; i++) { - if (!(sysctl_sched_features & (1UL << i))) - seq_puts(m, "NO_"); - seq_printf(m, "%s ", sched_feat_names[i]); - } - seq_puts(m, "\n"); - - return 0; -} - -static ssize_t -sched_feat_write(struct file *filp, const char __user *ubuf, - size_t cnt, loff_t *ppos) -{ - char buf[64]; - char *cmp = buf; - int neg = 0; - int i; - - if (cnt > 63) - cnt = 63; - - if (copy_from_user(&buf, ubuf, cnt)) - return -EFAULT; - - buf[cnt] = 0; - - if (strncmp(buf, "NO_", 3) == 0) { - neg = 1; - cmp += 3; - } - - for (i = 0; sched_feat_names[i]; i++) { - int len = strlen(sched_feat_names[i]); - - if (strncmp(cmp, sched_feat_names[i], len) == 0) { - if (neg) - sysctl_sched_features &= ~(1UL << i); - else - sysctl_sched_features |= (1UL << i); - break; - } - } - - if (!sched_feat_names[i]) - return -EINVAL; - - filp->f_pos += cnt; - - return cnt; -} - -static int sched_feat_open(struct inode *inode, struct file *filp) -{ - return single_open(filp, sched_feat_show, NULL); -} - -static struct file_operations sched_feat_fops = { - .open = sched_feat_open, - .write = sched_feat_write, - .read = seq_read, - .llseek = seq_lseek, - .release = single_release, -}; - -static __init int sched_init_debug(void) -{ - debugfs_create_file("sched_features", 0644, NULL, NULL, - &sched_feat_fops); - - return 0; -} -late_initcall(sched_init_debug); - -#endif - -#define sched_feat(x) (sysctl_sched_features & (1UL << __SCHED_FEAT_##x)) - -/* - * Number of tasks to iterate in a single balance run. - * Limited because this is done with IRQs disabled. - */ -const_debug unsigned int sysctl_sched_nr_migrate = 32; - -/* - * ratelimit for updating the group shares. - * default: 0.25ms - */ -unsigned int sysctl_sched_shares_ratelimit = 250000; - -/* - * Inject some fuzzyness into changing the per-cpu group shares - * this avoids remote rq-locks at the expense of fairness. - * default: 4 - */ -unsigned int sysctl_sched_shares_thresh = 4; - -/* - * period over which we measure -rt task cpu usage in us. - * default: 1s - */ -unsigned int sysctl_sched_rt_period = 1000000; - -static __read_mostly int scheduler_running; - -/* - * part of the period that we allow rt tasks to run in us. - * default: 0.95s - */ -int sysctl_sched_rt_runtime = 950000; - -static inline u64 global_rt_period(void) -{ - return (u64)sysctl_sched_rt_period * NSEC_PER_USEC; -} - -static inline u64 global_rt_runtime(void) -{ - if (sysctl_sched_rt_runtime < 0) - return RUNTIME_INF; - - return (u64)sysctl_sched_rt_runtime * NSEC_PER_USEC; -} - -#ifndef prepare_arch_switch -# define prepare_arch_switch(next) do { } while (0) -#endif -#ifndef finish_arch_switch -# define finish_arch_switch(prev) do { } while (0) -#endif - -static inline int task_current(struct rq *rq, struct task_struct *p) -{ - return rq->curr == p; -} - -#ifndef __ARCH_WANT_UNLOCKED_CTXSW -static inline int task_running(struct rq *rq, struct task_struct *p) -{ - return task_current(rq, p); -} - -static inline void prepare_lock_switch(struct rq *rq, struct task_struct *next) -{ -} - -static inline void finish_lock_switch(struct rq *rq, struct task_struct *prev) -{ -#ifdef CONFIG_DEBUG_SPINLOCK - /* this is a valid case when another task releases the spinlock */ - rq->lock.owner = current; -#endif - /* - * If we are tracking spinlock dependencies then we have to - * fix up the runqueue lock - which gets 'carried over' from - * prev into current: - */ - spin_acquire(&rq->lock.dep_map, 0, 0, _THIS_IP_); - - spin_unlock_irq(&rq->lock); -} - -#else /* __ARCH_WANT_UNLOCKED_CTXSW */ -static inline int task_running(struct rq *rq, struct task_struct *p) -{ -#ifdef CONFIG_SMP - return p->oncpu; -#else - return task_current(rq, p); -#endif -} - -static inline void prepare_lock_switch(struct rq *rq, struct task_struct *next) -{ -#ifdef CONFIG_SMP - /* - * We can optimise this out completely for !SMP, because the - * SMP rebalancing from interrupt is the only thing that cares - * here. - */ - next->oncpu = 1; -#endif -#ifdef __ARCH_WANT_INTERRUPTS_ON_CTXSW - spin_unlock_irq(&rq->lock); -#else - spin_unlock(&rq->lock); -#endif -} - -static inline void finish_lock_switch(struct rq *rq, struct task_struct *prev) -{ -#ifdef CONFIG_SMP - /* - * After ->oncpu is cleared, the task can be moved to a different CPU. - * We must ensure this doesn't happen until the switch is completely - * finished. - */ - smp_wmb(); - prev->oncpu = 0; -#endif -#ifndef __ARCH_WANT_INTERRUPTS_ON_CTXSW - local_irq_enable(); -#endif -} -#endif /* __ARCH_WANT_UNLOCKED_CTXSW */ - -/* - * __task_rq_lock - lock the runqueue a given task resides on. - * Must be called interrupts disabled. - */ -static inline struct rq *__task_rq_lock(struct task_struct *p) - __acquires(rq->lock) -{ - for (;;) { - struct rq *rq = task_rq(p); - spin_lock(&rq->lock); - if (likely(rq == task_rq(p))) - return rq; - spin_unlock(&rq->lock); - } -} - -/* - * task_rq_lock - lock the runqueue a given task resides on and disable - * interrupts. Note the ordering: we can safely lookup the task_rq without - * explicitly disabling preemption. - */ -static struct rq *task_rq_lock(struct task_struct *p, unsigned long *flags) - __acquires(rq->lock) -{ - struct rq *rq; - - for (;;) { - local_irq_save(*flags); - rq = task_rq(p); - spin_lock(&rq->lock); - if (likely(rq == task_rq(p))) - return rq; - spin_unlock_irqrestore(&rq->lock, *flags); - } -} - -void task_rq_unlock_wait(struct task_struct *p) -{ - struct rq *rq = task_rq(p); - - smp_mb(); /* spin-unlock-wait is not a full memory barrier */ - spin_unlock_wait(&rq->lock); -} - -static void __task_rq_unlock(struct rq *rq) - __releases(rq->lock) -{ - spin_unlock(&rq->lock); -} - -static inline void task_rq_unlock(struct rq *rq, unsigned long *flags) - __releases(rq->lock) -{ - spin_unlock_irqrestore(&rq->lock, *flags); -} - -/* - * this_rq_lock - lock this runqueue and disable interrupts. - */ -static struct rq *this_rq_lock(void) - __acquires(rq->lock) -{ - struct rq *rq; - - local_irq_disable(); - rq = this_rq(); - spin_lock(&rq->lock); - - return rq; -} - -#ifdef CONFIG_SCHED_HRTICK -/* - * Use HR-timers to deliver accurate preemption points. - * - * Its all a bit involved since we cannot program an hrt while holding the - * rq->lock. So what we do is store a state in in rq->hrtick_* and ask for a - * reschedule event. - * - * When we get rescheduled we reprogram the hrtick_timer outside of the - * rq->lock. - */ - -/* - * Use hrtick when: - * - enabled by features - * - hrtimer is actually high res - */ -static inline int hrtick_enabled(struct rq *rq) -{ - if (!sched_feat(HRTICK)) - return 0; - if (!cpu_active(cpu_of(rq))) - return 0; - return hrtimer_is_hres_active(&rq->hrtick_timer); -} - -static void hrtick_clear(struct rq *rq) -{ - if (hrtimer_active(&rq->hrtick_timer)) - hrtimer_cancel(&rq->hrtick_timer); -} - -/* - * High-resolution timer tick. - * Runs from hardirq context with interrupts disabled. - */ -static enum hrtimer_restart hrtick(struct hrtimer *timer) -{ - struct rq *rq = container_of(timer, struct rq, hrtick_timer); - - WARN_ON_ONCE(cpu_of(rq) != smp_processor_id()); - - spin_lock(&rq->lock); - update_rq_clock(rq); - rq->curr->sched_class->task_tick(rq, rq->curr, 1); - spin_unlock(&rq->lock); - - return HRTIMER_NORESTART; -} - -#ifdef CONFIG_SMP -/* - * called from hardirq (IPI) context - */ -static void __hrtick_start(void *arg) -{ - struct rq *rq = arg; - - spin_lock(&rq->lock); - hrtimer_restart(&rq->hrtick_timer); - rq->hrtick_csd_pending = 0; - spin_unlock(&rq->lock); -} - -/* - * Called to set the hrtick timer state. - * - * called with rq->lock held and irqs disabled - */ -static void hrtick_start(struct rq *rq, u64 delay) -{ - struct hrtimer *timer = &rq->hrtick_timer; - ktime_t time = ktime_add_ns(timer->base->get_time(), delay); - - hrtimer_set_expires(timer, time); - - if (rq == this_rq()) { - hrtimer_restart(timer); - } else if (!rq->hrtick_csd_pending) { - __smp_call_function_single(cpu_of(rq), &rq->hrtick_csd, 0); - rq->hrtick_csd_pending = 1; - } -} - -static int -hotplug_hrtick(struct notifier_block *nfb, unsigned long action, void *hcpu) -{ - int cpu = (int)(long)hcpu; - - switch (action) { - case CPU_UP_CANCELED: - case CPU_UP_CANCELED_FROZEN: - case CPU_DOWN_PREPARE: - case CPU_DOWN_PREPARE_FROZEN: - case CPU_DEAD: - case CPU_DEAD_FROZEN: - hrtick_clear(cpu_rq(cpu)); - return NOTIFY_OK; - } - - return NOTIFY_DONE; -} - -static __init void init_hrtick(void) -{ - hotcpu_notifier(hotplug_hrtick, 0); -} -#else -/* - * Called to set the hrtick timer state. - * - * called with rq->lock held and irqs disabled - */ -static void hrtick_start(struct rq *rq, u64 delay) -{ - __hrtimer_start_range_ns(&rq->hrtick_timer, ns_to_ktime(delay), 0, - HRTIMER_MODE_REL, 0); -} - -static inline void init_hrtick(void) -{ -} -#endif /* CONFIG_SMP */ - -static void init_rq_hrtick(struct rq *rq) -{ -#ifdef CONFIG_SMP - rq->hrtick_csd_pending = 0; - - rq->hrtick_csd.flags = 0; - rq->hrtick_csd.func = __hrtick_start; - rq->hrtick_csd.info = rq; -#endif - - hrtimer_init(&rq->hrtick_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); - rq->hrtick_timer.function = hrtick; -} -#else /* CONFIG_SCHED_HRTICK */ -static inline void hrtick_clear(struct rq *rq) -{ -} - -static inline void init_rq_hrtick(struct rq *rq) -{ -} - -static inline void init_hrtick(void) -{ -} -#endif /* CONFIG_SCHED_HRTICK */ - -/* - * resched_task - mark a task 'to be rescheduled now'. - * - * On UP this means the setting of the need_resched flag, on SMP it - * might also involve a cross-CPU call to trigger the scheduler on - * the target CPU. - */ -#ifdef CONFIG_SMP - -#ifndef tsk_is_polling -#define tsk_is_polling(t) test_tsk_thread_flag(t, TIF_POLLING_NRFLAG) -#endif - -static void resched_task(struct task_struct *p) -{ - int cpu; - - assert_spin_locked(&task_rq(p)->lock); - - if (test_tsk_need_resched(p)) - return; - - set_tsk_need_resched(p); - - cpu = task_cpu(p); - if (cpu == smp_processor_id()) - return; - - /* NEED_RESCHED must be visible before we test polling */ - smp_mb(); - if (!tsk_is_polling(p)) - smp_send_reschedule(cpu); -} - -static void resched_cpu(int cpu) -{ - struct rq *rq = cpu_rq(cpu); - unsigned long flags; - - if (!spin_trylock_irqsave(&rq->lock, flags)) - return; - resched_task(cpu_curr(cpu)); - spin_unlock_irqrestore(&rq->lock, flags); -} - -#ifdef CONFIG_NO_HZ -/* - * When add_timer_on() enqueues a timer into the timer wheel of an - * idle CPU then this timer might expire before the next timer event - * which is scheduled to wake up that CPU. In case of a completely - * idle system the next event might even be infinite time into the - * future. wake_up_idle_cpu() ensures that the CPU is woken up and - * leaves the inner idle loop so the newly added timer is taken into - * account when the CPU goes back to idle and evaluates the timer - * wheel for the next timer event. - */ -void wake_up_idle_cpu(int cpu) -{ - struct rq *rq = cpu_rq(cpu); - - if (cpu == smp_processor_id()) - return; - - /* - * This is safe, as this function is called with the timer - * wheel base lock of (cpu) held. When the CPU is on the way - * to idle and has not yet set rq->curr to idle then it will - * be serialized on the timer wheel base lock and take the new - * timer into account automatically. - */ - if (rq->curr != rq->idle) - return; - - /* - * We can set TIF_RESCHED on the idle task of the other CPU - * lockless. The worst case is that the other CPU runs the - * idle task through an additional NOOP schedule() - */ - set_tsk_need_resched(rq->idle); - - /* NEED_RESCHED must be visible before we test polling */ - smp_mb(); - if (!tsk_is_polling(rq->idle)) - smp_send_reschedule(cpu); -} -#endif /* CONFIG_NO_HZ */ - -#else /* !CONFIG_SMP */ -static void resched_task(struct task_struct *p) -{ - assert_spin_locked(&task_rq(p)->lock); - set_tsk_need_resched(p); -} -#endif /* CONFIG_SMP */ - -#if BITS_PER_LONG == 32 -# define WMULT_CONST (~0UL) -#else -# define WMULT_CONST (1UL << 32) -#endif - -#define WMULT_SHIFT 32 - -/* - * Shift right and round: - */ -#define SRR(x, y) (((x) + (1UL << ((y) - 1))) >> (y)) - -/* - * delta *= weight / lw - */ -static unsigned long -calc_delta_mine(unsigned long delta_exec, unsigned long weight, - struct load_weight *lw) -{ - u64 tmp; - - if (!lw->inv_weight) { - if (BITS_PER_LONG > 32 && unlikely(lw->weight >= WMULT_CONST)) - lw->inv_weight = 1; - else - lw->inv_weight = 1 + (WMULT_CONST-lw->weight/2) - / (lw->weight+1); - } - - tmp = (u64)delta_exec * weight; - /* - * Check whether we'd overflow the 64-bit multiplication: - */ - if (unlikely(tmp > WMULT_CONST)) - tmp = SRR(SRR(tmp, WMULT_SHIFT/2) * lw->inv_weight, - WMULT_SHIFT/2); - else - tmp = SRR(tmp * lw->inv_weight, WMULT_SHIFT); - - return (unsigned long)min(tmp, (u64)(unsigned long)LONG_MAX); -} - -static inline void update_load_add(struct load_weight *lw, unsigned long inc) -{ - lw->weight += inc; - lw->inv_weight = 0; -} - -static inline void update_load_sub(struct load_weight *lw, unsigned long dec) -{ - lw->weight -= dec; - lw->inv_weight = 0; -} - -/* - * To aid in avoiding the subversion of "niceness" due to uneven distribution - * of tasks with abnormal "nice" values across CPUs the contribution that - * each task makes to its run queue's load is weighted according to its - * scheduling class and "nice" value. For SCHED_NORMAL tasks this is just a - * scaled version of the new time slice allocation that they receive on time - * slice expiry etc. - */ - -#define WEIGHT_IDLEPRIO 3 -#define WMULT_IDLEPRIO 1431655765 - -/* - * Nice levels are multiplicative, with a gentle 10% change for every - * nice level changed. I.e. when a CPU-bound task goes from nice 0 to - * nice 1, it will get ~10% less CPU time than another CPU-bound task - * that remained on nice 0. - * - * The "10% effect" is relative and cumulative: from _any_ nice level, - * if you go up 1 level, it's -10% CPU usage, if you go down 1 level - * it's +10% CPU usage. (to achieve that we use a multiplier of 1.25. - * If a task goes up by ~10% and another task goes down by ~10% then - * the relative distance between them is ~25%.) - */ -static const int prio_to_weight[40] = { - /* -20 */ 88761, 71755, 56483, 46273, 36291, - /* -15 */ 29154, 23254, 18705, 14949, 11916, - /* -10 */ 9548, 7620, 6100, 4904, 3906, - /* -5 */ 3121, 2501, 1991, 1586, 1277, - /* 0 */ 1024, 820, 655, 526, 423, - /* 5 */ 335, 272, 215, 172, 137, - /* 10 */ 110, 87, 70, 56, 45, - /* 15 */ 36, 29, 23, 18, 15, -}; - -/* - * Inverse (2^32/x) values of the prio_to_weight[] array, precalculated. - * - * In cases where the weight does not change often, we can use the - * precalculated inverse to speed up arithmetics by turning divisions - * into multiplications: - */ -static const u32 prio_to_wmult[40] = { - /* -20 */ 48388, 59856, 76040, 92818, 118348, - /* -15 */ 147320, 184698, 229616, 287308, 360437, - /* -10 */ 449829, 563644, 704093, 875809, 1099582, - /* -5 */ 1376151, 1717300, 2157191, 2708050, 3363326, - /* 0 */ 4194304, 5237765, 6557202, 8165337, 10153587, - /* 5 */ 12820798, 15790321, 19976592, 24970740, 31350126, - /* 10 */ 39045157, 49367440, 61356676, 76695844, 95443717, - /* 15 */ 119304647, 148102320, 186737708, 238609294, 286331153, -}; - -static void activate_task(struct rq *rq, struct task_struct *p, int wakeup); - -/* - * runqueue iterator, to support SMP load-balancing between different - * scheduling classes, without having to expose their internal data - * structures to the load-balancing proper: - */ -struct rq_iterator { - void *arg; - struct task_struct *(*start)(void *); - struct task_struct *(*next)(void *); -}; - -#ifdef CONFIG_SMP -static unsigned long -balance_tasks(struct rq *this_rq, int this_cpu, struct rq *busiest, - unsigned long max_load_move, struct sched_domain *sd, - enum cpu_idle_type idle, int *all_pinned, - int *this_best_prio, struct rq_iterator *iterator); - -static int -iter_move_one_task(struct rq *this_rq, int this_cpu, struct rq *busiest, - struct sched_domain *sd, enum cpu_idle_type idle, - struct rq_iterator *iterator); -#endif - -/* Time spent by the tasks of the cpu accounting group executing in ... */ -enum cpuacct_stat_index { - CPUACCT_STAT_USER, /* ... user mode */ - CPUACCT_STAT_SYSTEM, /* ... kernel mode */ - - CPUACCT_STAT_NSTATS, -}; - -#ifdef CONFIG_CGROUP_CPUACCT -static void cpuacct_charge(struct task_struct *tsk, u64 cputime); -static void cpuacct_update_stats(struct task_struct *tsk, - enum cpuacct_stat_index idx, cputime_t val); -#else -static inline void cpuacct_charge(struct task_struct *tsk, u64 cputime) {} -static inline void cpuacct_update_stats(struct task_struct *tsk, - enum cpuacct_stat_index idx, cputime_t val) {} -#endif - -static inline void inc_cpu_load(struct rq *rq, unsigned long load) -{ - update_load_add(&rq->load, load); -} - -static inline void dec_cpu_load(struct rq *rq, unsigned long load) -{ - update_load_sub(&rq->load, load); -} - -#if (defined(CONFIG_SMP) && defined(CONFIG_FAIR_GROUP_SCHED)) || defined(CONFIG_RT_GROUP_SCHED) -typedef int (*tg_visitor)(struct task_group *, void *); - -/* - * Iterate the full tree, calling @down when first entering a node and @up when - * leaving it for the final time. - */ -static int walk_tg_tree(tg_visitor down, tg_visitor up, void *data) -{ - struct task_group *parent, *child; - int ret; - - rcu_read_lock(); - parent = &root_task_group; -down: - ret = (*down)(parent, data); - if (ret) - goto out_unlock; - list_for_each_entry_rcu(child, &parent->children, siblings) { - parent = child; - goto down; - -up: - continue; - } - ret = (*up)(parent, data); - if (ret) - goto out_unlock; - - child = parent; - parent = parent->parent; - if (parent) - goto up; -out_unlock: - rcu_read_unlock(); - - return ret; -} - -static int tg_nop(struct task_group *tg, void *data) -{ - return 0; -} -#endif - -#ifdef CONFIG_SMP -static unsigned long source_load(int cpu, int type); -static unsigned long target_load(int cpu, int type); -static int task_hot(struct task_struct *p, u64 now, struct sched_domain *sd); - -static unsigned long cpu_avg_load_per_task(int cpu) -{ - struct rq *rq = cpu_rq(cpu); - unsigned long nr_running = ACCESS_ONCE(rq->nr_running); - - if (nr_running) - rq->avg_load_per_task = rq->load.weight / nr_running; - else - rq->avg_load_per_task = 0; - - return rq->avg_load_per_task; -} - -#ifdef CONFIG_FAIR_GROUP_SCHED - -static void __set_se_shares(struct sched_entity *se, unsigned long shares); - -/* - * Calculate and set the cpu's group shares. - */ -static void -update_group_shares_cpu(struct task_group *tg, int cpu, - unsigned long sd_shares, unsigned long sd_rq_weight) -{ - unsigned long shares; - unsigned long rq_weight; - - if (!tg->se[cpu]) - return; - - rq_weight = tg->cfs_rq[cpu]->rq_weight; - - /* - * \Sum shares * rq_weight - * shares = ----------------------- - * \Sum rq_weight - * - */ - shares = (sd_shares * rq_weight) / sd_rq_weight; - shares = clamp_t(unsigned long, shares, MIN_SHARES, MAX_SHARES); - - if (abs(shares - tg->se[cpu]->load.weight) > - sysctl_sched_shares_thresh) { - struct rq *rq = cpu_rq(cpu); - unsigned long flags; - - spin_lock_irqsave(&rq->lock, flags); - tg->cfs_rq[cpu]->shares = shares; - - __set_se_shares(tg->se[cpu], shares); - spin_unlock_irqrestore(&rq->lock, flags); - } -} - -/* - * Re-compute the task group their per cpu shares over the given domain. - * This needs to be done in a bottom-up fashion because the rq weight of a - * parent group depends on the shares of its child groups. - */ -static int tg_shares_up(struct task_group *tg, void *data) -{ - unsigned long weight, rq_weight = 0; - unsigned long shares = 0; - struct sched_domain *sd = data; - int i; - - for_each_cpu(i, sched_domain_span(sd)) { - /* - * If there are currently no tasks on the cpu pretend there - * is one of average load so that when a new task gets to - * run here it will not get delayed by group starvation. - */ - weight = tg->cfs_rq[i]->load.weight; - if (!weight) - weight = NICE_0_LOAD; - - tg->cfs_rq[i]->rq_weight = weight; - rq_weight += weight; - shares += tg->cfs_rq[i]->shares; - } - - if ((!shares && rq_weight) || shares > tg->shares) - shares = tg->shares; - - if (!sd->parent || !(sd->parent->flags & SD_LOAD_BALANCE)) - shares = tg->shares; - - for_each_cpu(i, sched_domain_span(sd)) - update_group_shares_cpu(tg, i, shares, rq_weight); - - return 0; -} - -/* - * Compute the cpu's hierarchical load factor for each task group. - * This needs to be done in a top-down fashion because the load of a child - * group is a fraction of its parents load. - */ -static int tg_load_down(struct task_group *tg, void *data) -{ - unsigned long load; - long cpu = (long)data; - - if (!tg->parent) { - load = cpu_rq(cpu)->load.weight; - } else { - load = tg->parent->cfs_rq[cpu]->h_load; - load *= tg->cfs_rq[cpu]->shares; - load /= tg->parent->cfs_rq[cpu]->load.weight + 1; - } - - tg->cfs_rq[cpu]->h_load = load; - - return 0; -} - -static void update_shares(struct sched_domain *sd) -{ - u64 now = cpu_clock(raw_smp_processor_id()); - s64 elapsed = now - sd->last_update; - - if (elapsed >= (s64)(u64)sysctl_sched_shares_ratelimit) { - sd->last_update = now; - walk_tg_tree(tg_nop, tg_shares_up, sd); - } -} - -static void update_shares_locked(struct rq *rq, struct sched_domain *sd) -{ - spin_unlock(&rq->lock); - update_shares(sd); - spin_lock(&rq->lock); -} - -static void update_h_load(long cpu) -{ - walk_tg_tree(tg_load_down, tg_nop, (void *)cpu); -} - -#else - -static inline void update_shares(struct sched_domain *sd) -{ -} - -static inline void update_shares_locked(struct rq *rq, struct sched_domain *sd) -{ -} - -#endif - -#ifdef CONFIG_PREEMPT - -/* - * fair double_lock_balance: Safely acquires both rq->locks in a fair - * way at the expense of forcing extra atomic operations in all - * invocations. This assures that the double_lock is acquired using the - * same underlying policy as the spinlock_t on this architecture, which - * reduces latency compared to the unfair variant below. However, it - * also adds more overhead and therefore may reduce throughput. - */ -static inline int _double_lock_balance(struct rq *this_rq, struct rq *busiest) - __releases(this_rq->lock) - __acquires(busiest->lock) - __acquires(this_rq->lock) -{ - spin_unlock(&this_rq->lock); - double_rq_lock(this_rq, busiest); - - return 1; -} - -#else -/* - * Unfair double_lock_balance: Optimizes throughput at the expense of - * latency by eliminating extra atomic operations when the locks are - * already in proper order on entry. This favors lower cpu-ids and will - * grant the double lock to lower cpus over higher ids under contention, - * regardless of entry order into the function. - */ -static int _double_lock_balance(struct rq *this_rq, struct rq *busiest) - __releases(this_rq->lock) - __acquires(busiest->lock) - __acquires(this_rq->lock) -{ - int ret = 0; - - if (unlikely(!spin_trylock(&busiest->lock))) { - if (busiest < this_rq) { - spin_unlock(&this_rq->lock); - spin_lock(&busiest->lock); - spin_lock_nested(&this_rq->lock, SINGLE_DEPTH_NESTING); - ret = 1; - } else - spin_lock_nested(&busiest->lock, SINGLE_DEPTH_NESTING); - } - return ret; -} - -#endif /* CONFIG_PREEMPT */ - -/* - * double_lock_balance - lock the busiest runqueue, this_rq is locked already. - */ -static int double_lock_balance(struct rq *this_rq, struct rq *busiest) -{ - if (unlikely(!irqs_disabled())) { - /* printk() doesn't work good under rq->lock */ - spin_unlock(&this_rq->lock); - BUG_ON(1); - } - - return _double_lock_balance(this_rq, busiest); -} - -static inline void double_unlock_balance(struct rq *this_rq, struct rq *busiest) - __releases(busiest->lock) -{ - spin_unlock(&busiest->lock); - lock_set_subclass(&this_rq->lock.dep_map, 0, _RET_IP_); -} -#endif - -#ifdef CONFIG_FAIR_GROUP_SCHED -static void cfs_rq_set_shares(struct cfs_rq *cfs_rq, unsigned long shares) -{ -#ifdef CONFIG_SMP - cfs_rq->shares = shares; -#endif -} -#endif - -#include "sched_stats.h" -#include "sched_idletask.c" -#include "sched_fair.c" -#include "sched_rt.c" -#ifdef CONFIG_SCHED_DEBUG -# include "sched_debug.c" -#endif - -#define sched_class_highest (&rt_sched_class) -#define for_each_class(class) \ - for (class = sched_class_highest; class; class = class->next) - -static void inc_nr_running(struct rq *rq) -{ - rq->nr_running++; -} - -static void dec_nr_running(struct rq *rq) -{ - rq->nr_running--; -} - -static void set_load_weight(struct task_struct *p) -{ - if (task_has_rt_policy(p)) { - p->se.load.weight = prio_to_weight[0] * 2; - p->se.load.inv_weight = prio_to_wmult[0] >> 1; - return; - } - - /* - * SCHED_IDLE tasks get minimal weight: - */ - if (p->policy == SCHED_IDLE) { - p->se.load.weight = WEIGHT_IDLEPRIO; - p->se.load.inv_weight = WMULT_IDLEPRIO; - return; - } - - p->se.load.weight = prio_to_weight[p->static_prio - MAX_RT_PRIO]; - p->se.load.inv_weight = prio_to_wmult[p->static_prio - MAX_RT_PRIO]; -} - -static void update_avg(u64 *avg, u64 sample) -{ - s64 diff = sample - *avg; - *avg += diff >> 3; -} - -static void enqueue_task(struct rq *rq, struct task_struct *p, int wakeup) -{ - if (wakeup) - p->se.start_runtime = p->se.sum_exec_runtime; - - sched_info_queued(p); - p->sched_class->enqueue_task(rq, p, wakeup); - p->se.on_rq = 1; -} - -static void dequeue_task(struct rq *rq, struct task_struct *p, int sleep) -{ - if (sleep) { - if (p->se.last_wakeup) { - update_avg(&p->se.avg_overlap, - p->se.sum_exec_runtime - p->se.last_wakeup); - p->se.last_wakeup = 0; - } else { - update_avg(&p->se.avg_wakeup, - sysctl_sched_wakeup_granularity); - } - } - - sched_info_dequeued(p); - p->sched_class->dequeue_task(rq, p, sleep); - p->se.on_rq = 0; -} - -/* - * __normal_prio - return the priority that is based on the static prio - */ -static inline int __normal_prio(struct task_struct *p) -{ - return p->static_prio; -} - -/* - * Calculate the expected normal priority: i.e. priority - * without taking RT-inheritance into account. Might be - * boosted by interactivity modifiers. Changes upon fork, - * setprio syscalls, and whenever the interactivity - * estimator recalculates. - */ -static inline int normal_prio(struct task_struct *p) -{ - int prio; - - if (task_has_rt_policy(p)) - prio = MAX_RT_PRIO-1 - p->rt_priority; - else - prio = __normal_prio(p); - return prio; -} - -/* - * Calculate the current priority, i.e. the priority - * taken into account by the scheduler. This value might - * be boosted by RT tasks, or might be boosted by - * interactivity modifiers. Will be RT if the task got - * RT-boosted. If not then it returns p->normal_prio. - */ -static int effective_prio(struct task_struct *p) -{ - p->normal_prio = normal_prio(p); - /* - * If we are RT tasks or we were boosted to RT priority, - * keep the priority unchanged. Otherwise, update priority - * to the normal priority: - */ - if (!rt_prio(p->prio)) - return p->normal_prio; - return p->prio; -} - -/* - * activate_task - move a task to the runqueue. - */ -static void activate_task(struct rq *rq, struct task_struct *p, int wakeup) -{ - if (task_contributes_to_load(p)) - rq->nr_uninterruptible--; - - enqueue_task(rq, p, wakeup); - inc_nr_running(rq); -} - -/* - * deactivate_task - remove a task from the runqueue. - */ -static void deactivate_task(struct rq *rq, struct task_struct *p, int sleep) -{ - if (task_contributes_to_load(p)) - rq->nr_uninterruptible++; - - dequeue_task(rq, p, sleep); - dec_nr_running(rq); -} - -/** - * task_curr - is this task currently executing on a CPU? - * @p: the task in question. - */ -inline int task_curr(const struct task_struct *p) -{ - return cpu_curr(task_cpu(p)) == p; -} - -static inline void __set_task_cpu(struct task_struct *p, unsigned int cpu) -{ - set_task_rq(p, cpu); -#ifdef CONFIG_SMP - /* - * After ->cpu is set up to a new value, task_rq_lock(p, ...) can be - * successfuly executed on another CPU. We must ensure that updates of - * per-task data have been completed by this moment. - */ - smp_wmb(); - task_thread_info(p)->cpu = cpu; -#endif -} - -static inline void check_class_changed(struct rq *rq, struct task_struct *p, - const struct sched_class *prev_class, - int oldprio, int running) -{ - if (prev_class != p->sched_class) { - if (prev_class->switched_from) - prev_class->switched_from(rq, p, running); - p->sched_class->switched_to(rq, p, running); - } else - p->sched_class->prio_changed(rq, p, oldprio, running); -} - -#ifdef CONFIG_SMP - -/* Used instead of source_load when we know the type == 0 */ -static unsigned long weighted_cpuload(const int cpu) -{ - return cpu_rq(cpu)->load.weight; -} - -/* - * Is this task likely cache-hot: - */ -static int -task_hot(struct task_struct *p, u64 now, struct sched_domain *sd) -{ - s64 delta; - - /* - * Buddy candidates are cache hot: - */ - if (sched_feat(CACHE_HOT_BUDDY) && - (&p->se == cfs_rq_of(&p->se)->next || - &p->se == cfs_rq_of(&p->se)->last)) - return 1; - - if (p->sched_class != &fair_sched_class) - return 0; - - if (sysctl_sched_migration_cost == -1) - return 1; - if (sysctl_sched_migration_cost == 0) - return 0; - - delta = now - p->se.exec_start; - - return delta < (s64)sysctl_sched_migration_cost; -} - - -void set_task_cpu(struct task_struct *p, unsigned int new_cpu) -{ - int old_cpu = task_cpu(p); - struct rq *old_rq = cpu_rq(old_cpu), *new_rq = cpu_rq(new_cpu); - struct cfs_rq *old_cfsrq = task_cfs_rq(p), - *new_cfsrq = cpu_cfs_rq(old_cfsrq, new_cpu); - u64 clock_offset; - - clock_offset = old_rq->clock - new_rq->clock; - - trace_sched_migrate_task(p, task_cpu(p), new_cpu); - -#ifdef CONFIG_SCHEDSTATS - if (p->se.wait_start) - p->se.wait_start -= clock_offset; - if (p->se.sleep_start) - p->se.sleep_start -= clock_offset; - if (p->se.block_start) - p->se.block_start -= clock_offset; - if (old_cpu != new_cpu) { - schedstat_inc(p, se.nr_migrations); - if (task_hot(p, old_rq->clock, NULL)) - schedstat_inc(p, se.nr_forced2_migrations); - } -#endif - p->se.vruntime -= old_cfsrq->min_vruntime - - new_cfsrq->min_vruntime; - - __set_task_cpu(p, new_cpu); -} - -struct migration_req { - struct list_head list; - - struct task_struct *task; - int dest_cpu; - - struct completion done; -}; - -/* - * The task's runqueue lock must be held. - * Returns true if you have to wait for migration thread. - */ -static int -migrate_task(struct task_struct *p, int dest_cpu, struct migration_req *req) -{ - struct rq *rq = task_rq(p); - - /* - * If the task is not on a runqueue (and not running), then - * it is sufficient to simply update the task's cpu field. - */ - if (!p->se.on_rq && !task_running(rq, p)) { - set_task_cpu(p, dest_cpu); - return 0; - } - - init_completion(&req->done); - req->task = p; - req->dest_cpu = dest_cpu; - list_add(&req->list, &rq->migration_queue); - - return 1; -} - -/* - * wait_task_inactive - wait for a thread to unschedule. - * - * If @match_state is nonzero, it's the @p->state value just checked and - * not expected to change. If it changes, i.e. @p might have woken up, - * then return zero. When we succeed in waiting for @p to be off its CPU, - * we return a positive number (its total switch count). If a second call - * a short while later returns the same number, the caller can be sure that - * @p has remained unscheduled the whole time. - * - * The caller must ensure that the task *will* unschedule sometime soon, - * else this function might spin for a *long* time. This function can't - * be called with interrupts off, or it may introduce deadlock with - * smp_call_function() if an IPI is sent by the same process we are - * waiting to become inactive. - */ -unsigned long wait_task_inactive(struct task_struct *p, long match_state) -{ - unsigned long flags; - int running, on_rq; - unsigned long ncsw; - struct rq *rq; - - for (;;) { - /* - * We do the initial early heuristics without holding - * any task-queue locks at all. We'll only try to get - * the runqueue lock when things look like they will - * work out! - */ - rq = task_rq(p); - - /* - * If the task is actively running on another CPU - * still, just relax and busy-wait without holding - * any locks. - * - * NOTE! Since we don't hold any locks, it's not - * even sure that "rq" stays as the right runqueue! - * But we don't care, since "task_running()" will - * return false if the runqueue has changed and p - * is actually now running somewhere else! - */ - while (task_running(rq, p)) { - if (match_state && unlikely(p->state != match_state)) - return 0; - cpu_relax(); - } - - /* - * Ok, time to look more closely! We need the rq - * lock now, to be *sure*. If we're wrong, we'll - * just go back and repeat. - */ - rq = task_rq_lock(p, &flags); - trace_sched_wait_task(rq, p); - running = task_running(rq, p); - on_rq = p->se.on_rq; - ncsw = 0; - if (!match_state || p->state == match_state) - ncsw = p->nvcsw | LONG_MIN; /* sets MSB */ - task_rq_unlock(rq, &flags); - - /* - * If it changed from the expected state, bail out now. - */ - if (unlikely(!ncsw)) - break; - - /* - * Was it really running after all now that we - * checked with the proper locks actually held? - * - * Oops. Go back and try again.. - */ - if (unlikely(running)) { - cpu_relax(); - continue; - } - - /* - * It's not enough that it's not actively running, - * it must be off the runqueue _entirely_, and not - * preempted! - * - * So if it was still runnable (but just not actively - * running right now), it's preempted, and we should - * yield - it could be a while. - */ - if (unlikely(on_rq)) { - schedule_timeout_uninterruptible(1); - continue; - } - - /* - * Ahh, all good. It wasn't running, and it wasn't - * runnable, which means that it will never become - * running in the future either. We're all done! - */ - break; - } - - return ncsw; -} - -/*** - * kick_process - kick a running thread to enter/exit the kernel - * @p: the to-be-kicked thread - * - * Cause a process which is running on another CPU to enter - * kernel-mode, without any delay. (to get signals handled.) - * - * NOTE: this function doesnt have to take the runqueue lock, - * because all it wants to ensure is that the remote task enters - * the kernel. If the IPI races and the task has been migrated - * to another CPU then no harm is done and the purpose has been - * achieved as well. - */ -void kick_process(struct task_struct *p) -{ - int cpu; - - preempt_disable(); - cpu = task_cpu(p); - if ((cpu != smp_processor_id()) && task_curr(p)) - smp_send_reschedule(cpu); - preempt_enable(); -} - -/* - * Return a low guess at the load of a migration-source cpu weighted - * according to the scheduling class and "nice" value. - * - * We want to under-estimate the load of migration sources, to - * balance conservatively. - */ -static unsigned long source_load(int cpu, int type) -{ - struct rq *rq = cpu_rq(cpu); - unsigned long total = weighted_cpuload(cpu); - - if (type == 0 || !sched_feat(LB_BIAS)) - return total; - - return min(rq->cpu_load[type-1], total); -} - -/* - * Return a high guess at the load of a migration-target cpu weighted - * according to the scheduling class and "nice" value. - */ -static unsigned long target_load(int cpu, int type) -{ - struct rq *rq = cpu_rq(cpu); - unsigned long total = weighted_cpuload(cpu); - - if (type == 0 || !sched_feat(LB_BIAS)) - return total; - - return max(rq->cpu_load[type-1], total); -} - -/* - * find_idlest_group finds and returns the least busy CPU group within the - * domain. - */ -static struct sched_group * -find_idlest_group(struct sched_domain *sd, struct task_struct *p, int this_cpu) -{ - struct sched_group *idlest = NULL, *this = NULL, *group = sd->groups; - unsigned long min_load = ULONG_MAX, this_load = 0; - int load_idx = sd->forkexec_idx; - int imbalance = 100 + (sd->imbalance_pct-100)/2; - - do { - unsigned long load, avg_load; - int local_group; - int i; - - /* Skip over this group if it has no CPUs allowed */ - if (!cpumask_intersects(sched_group_cpus(group), - &p->cpus_allowed)) - continue; - - local_group = cpumask_test_cpu(this_cpu, - sched_group_cpus(group)); - - /* Tally up the load of all CPUs in the group */ - avg_load = 0; - - for_each_cpu(i, sched_group_cpus(group)) { - /* Bias balancing toward cpus of our domain */ - if (local_group) - load = source_load(i, load_idx); - else - load = target_load(i, load_idx); - - avg_load += load; - } - - /* Adjust by relative CPU power of the group */ - avg_load = sg_div_cpu_power(group, - avg_load * SCHED_LOAD_SCALE); - - if (local_group) { - this_load = avg_load; - this = group; - } else if (avg_load < min_load) { - min_load = avg_load; - idlest = group; - } - } while (group = group->next, group != sd->groups); - - if (!idlest || 100*this_load < imbalance*min_load) - return NULL; - return idlest; -} - -/* - * find_idlest_cpu - find the idlest cpu among the cpus in group. - */ -static int -find_idlest_cpu(struct sched_group *group, struct task_struct *p, int this_cpu) -{ - unsigned long load, min_load = ULONG_MAX; - int idlest = -1; - int i; - - /* Traverse only the allowed CPUs */ - for_each_cpu_and(i, sched_group_cpus(group), &p->cpus_allowed) { - load = weighted_cpuload(i); - - if (load < min_load || (load == min_load && i == this_cpu)) { - min_load = load; - idlest = i; - } - } - - return idlest; -} - -/* - * sched_balance_self: balance the current task (running on cpu) in domains - * that have the 'flag' flag set. In practice, this is SD_BALANCE_FORK and - * SD_BALANCE_EXEC. - * - * Balance, ie. select the least loaded group. - * - * Returns the target CPU number, or the same CPU if no balancing is needed. - * - * preempt must be disabled. - */ -static int sched_balance_self(int cpu, int flag) -{ - struct task_struct *t = current; - struct sched_domain *tmp, *sd = NULL; - - for_each_domain(cpu, tmp) { - /* - * If power savings logic is enabled for a domain, stop there. - */ - if (tmp->flags & SD_POWERSAVINGS_BALANCE) - break; - if (tmp->flags & flag) - sd = tmp; - } - - if (sd) - update_shares(sd); - - while (sd) { - struct sched_group *group; - int new_cpu, weight; - - if (!(sd->flags & flag)) { - sd = sd->child; - continue; - } - - group = find_idlest_group(sd, t, cpu); - if (!group) { - sd = sd->child; - continue; - } - - new_cpu = find_idlest_cpu(group, t, cpu); - if (new_cpu == -1 || new_cpu == cpu) { - /* Now try balancing at a lower domain level of cpu */ - sd = sd->child; - continue; - } - - /* Now try balancing at a lower domain level of new_cpu */ - cpu = new_cpu; - weight = cpumask_weight(sched_domain_span(sd)); - sd = NULL; - for_each_domain(cpu, tmp) { - if (weight <= cpumask_weight(sched_domain_span(tmp))) - break; - if (tmp->flags & flag) - sd = tmp; - } - /* while loop will break here if sd == NULL */ - } - - return cpu; -} - -#endif /* CONFIG_SMP */ - -/*** - * try_to_wake_up - wake up a thread - * @p: the to-be-woken-up thread - * @state: the mask of task states that can be woken - * @sync: do a synchronous wakeup? - * - * Put it on the run-queue if it's not already there. The "current" - * thread is always on the run-queue (except when the actual - * re-schedule is in progress), and as such you're allowed to do - * the simpler "current->state = TASK_RUNNING" to mark yourself - * runnable without the overhead of this. - * - * returns failure only if the task is already active. - */ -static int try_to_wake_up(struct task_struct *p, unsigned int state, int sync) -{ - int cpu, orig_cpu, this_cpu, success = 0; - unsigned long flags; - long old_state; - struct rq *rq; - - if (!sched_feat(SYNC_WAKEUPS)) - sync = 0; - -#ifdef CONFIG_SMP - if (sched_feat(LB_WAKEUP_UPDATE) && !root_task_group_empty()) { - struct sched_domain *sd; - - this_cpu = raw_smp_processor_id(); - cpu = task_cpu(p); - - for_each_domain(this_cpu, sd) { - if (cpumask_test_cpu(cpu, sched_domain_span(sd))) { - update_shares(sd); - break; - } - } - } -#endif - - smp_wmb(); - rq = task_rq_lock(p, &flags); - update_rq_clock(rq); - old_state = p->state; - if (!(old_state & state)) - goto out; - - if (p->se.on_rq) - goto out_running; - - cpu = task_cpu(p); - orig_cpu = cpu; - this_cpu = smp_processor_id(); - -#ifdef CONFIG_SMP - if (unlikely(task_running(rq, p))) - goto out_activate; - - cpu = p->sched_class->select_task_rq(p, sync); - if (cpu != orig_cpu) { - set_task_cpu(p, cpu); - task_rq_unlock(rq, &flags); - /* might preempt at this point */ - rq = task_rq_lock(p, &flags); - old_state = p->state; - if (!(old_state & state)) - goto out; - if (p->se.on_rq) - goto out_running; - - this_cpu = smp_processor_id(); - cpu = task_cpu(p); - } - -#ifdef CONFIG_SCHEDSTATS - schedstat_inc(rq, ttwu_count); - if (cpu == this_cpu) - schedstat_inc(rq, ttwu_local); - else { - struct sched_domain *sd; - for_each_domain(this_cpu, sd) { - if (cpumask_test_cpu(cpu, sched_domain_span(sd))) { - schedstat_inc(sd, ttwu_wake_remote); - break; - } - } - } -#endif /* CONFIG_SCHEDSTATS */ - -out_activate: -#endif /* CONFIG_SMP */ - schedstat_inc(p, se.nr_wakeups); - if (sync) - schedstat_inc(p, se.nr_wakeups_sync); - if (orig_cpu != cpu) - schedstat_inc(p, se.nr_wakeups_migrate); - if (cpu == this_cpu) - schedstat_inc(p, se.nr_wakeups_local); - else - schedstat_inc(p, se.nr_wakeups_remote); - activate_task(rq, p, 1); - success = 1; - - /* - * Only attribute actual wakeups done by this task. - */ - if (!in_interrupt()) { - struct sched_entity *se = ¤t->se; - u64 sample = se->sum_exec_runtime; - - if (se->last_wakeup) - sample -= se->last_wakeup; - else - sample -= se->start_runtime; - update_avg(&se->avg_wakeup, sample); - - se->last_wakeup = se->sum_exec_runtime; - } - -out_running: - trace_sched_wakeup(rq, p, success); - check_preempt_curr(rq, p, sync); - - p->state = TASK_RUNNING; -#ifdef CONFIG_SMP - if (p->sched_class->task_wake_up) - p->sched_class->task_wake_up(rq, p); -#endif -out: - task_rq_unlock(rq, &flags); - - return success; -} - -int wake_up_process(struct task_struct *p) -{ - return try_to_wake_up(p, TASK_ALL, 0); -} -EXPORT_SYMBOL(wake_up_process); - -int wake_up_state(struct task_struct *p, unsigned int state) -{ - return try_to_wake_up(p, state, 0); -} - -/* - * Perform scheduler related setup for a newly forked process p. - * p is forked by current. - * - * __sched_fork() is basic setup used by init_idle() too: - */ -static void __sched_fork(struct task_struct *p) -{ - p->se.exec_start = 0; - p->se.sum_exec_runtime = 0; - p->se.prev_sum_exec_runtime = 0; - p->se.last_wakeup = 0; - p->se.avg_overlap = 0; - p->se.start_runtime = 0; - p->se.avg_wakeup = sysctl_sched_wakeup_granularity; - -#ifdef CONFIG_SCHEDSTATS - p->se.wait_start = 0; - p->se.sum_sleep_runtime = 0; - p->se.sleep_start = 0; - p->se.block_start = 0; - p->se.sleep_max = 0; - p->se.block_max = 0; - p->se.exec_max = 0; - p->se.slice_max = 0; - p->se.wait_max = 0; -#endif - - INIT_LIST_HEAD(&p->rt.run_list); - p->se.on_rq = 0; - INIT_LIST_HEAD(&p->se.group_node); - -#ifdef CONFIG_PREEMPT_NOTIFIERS - INIT_HLIST_HEAD(&p->preempt_notifiers); -#endif - - /* - * We mark the process as running here, but have not actually - * inserted it onto the runqueue yet. This guarantees that - * nobody will actually run it, and a signal or other external - * event cannot wake it up and insert it on the runqueue either. - */ - p->state = TASK_RUNNING; -} - -/* - * fork()/clone()-time setup: - */ -void sched_fork(struct task_struct *p, int clone_flags) -{ - int cpu = get_cpu(); - - __sched_fork(p); - -#ifdef CONFIG_SMP - cpu = sched_balance_self(cpu, SD_BALANCE_FORK); -#endif - set_task_cpu(p, cpu); - - /* - * Make sure we do not leak PI boosting priority to the child: - */ - p->prio = current->normal_prio; - if (!rt_prio(p->prio)) - p->sched_class = &fair_sched_class; - -#if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT) - if (likely(sched_info_on())) - memset(&p->sched_info, 0, sizeof(p->sched_info)); -#endif -#if defined(CONFIG_SMP) && defined(__ARCH_WANT_UNLOCKED_CTXSW) - p->oncpu = 0; -#endif -#ifdef CONFIG_PREEMPT - /* Want to start with kernel preemption disabled. */ - task_thread_info(p)->preempt_count = 1; -#endif - plist_node_init(&p->pushable_tasks, MAX_PRIO); - - put_cpu(); -} - -/* - * wake_up_new_task - wake up a newly created task for the first time. - * - * This function will do some initial scheduler statistics housekeeping - * that must be done for every newly created context, then puts the task - * on the runqueue and wakes it. - */ -void wake_up_new_task(struct task_struct *p, unsigned long clone_flags) -{ - unsigned long flags; - struct rq *rq; - - rq = task_rq_lock(p, &flags); - BUG_ON(p->state != TASK_RUNNING); - update_rq_clock(rq); - - p->prio = effective_prio(p); - - if (!p->sched_class->task_new || !current->se.on_rq) { - activate_task(rq, p, 0); - } else { - /* - * Let the scheduling class do new task startup - * management (if any): - */ - p->sched_class->task_new(rq, p); - inc_nr_running(rq); - } - trace_sched_wakeup_new(rq, p, 1); - check_preempt_curr(rq, p, 0); -#ifdef CONFIG_SMP - if (p->sched_class->task_wake_up) - p->sched_class->task_wake_up(rq, p); -#endif - task_rq_unlock(rq, &flags); -} - -#ifdef CONFIG_PREEMPT_NOTIFIERS - -/** - * preempt_notifier_register - tell me when current is being preempted & rescheduled - * @notifier: notifier struct to register - */ -void preempt_notifier_register(struct preempt_notifier *notifier) -{ - hlist_add_head(¬ifier->link, ¤t->preempt_notifiers); -} -EXPORT_SYMBOL_GPL(preempt_notifier_register); - -/** - * preempt_notifier_unregister - no longer interested in preemption notifications - * @notifier: notifier struct to unregister - * - * This is safe to call from within a preemption notifier. - */ -void preempt_notifier_unregister(struct preempt_notifier *notifier) -{ - hlist_del(¬ifier->link); -} -EXPORT_SYMBOL_GPL(preempt_notifier_unregister); - -static void fire_sched_in_preempt_notifiers(struct task_struct *curr) -{ - struct preempt_notifier *notifier; - struct hlist_node *node; - - hlist_for_each_entry(notifier, node, &curr->preempt_notifiers, link) - notifier->ops->sched_in(notifier, raw_smp_processor_id()); -} - -static void -fire_sched_out_preempt_notifiers(struct task_struct *curr, - struct task_struct *next) -{ - struct preempt_notifier *notifier; - struct hlist_node *node; - - hlist_for_each_entry(notifier, node, &curr->preempt_notifiers, link) - notifier->ops->sched_out(notifier, next); -} - -#else /* !CONFIG_PREEMPT_NOTIFIERS */ - -static void fire_sched_in_preempt_notifiers(struct task_struct *curr) -{ -} - -static void -fire_sched_out_preempt_notifiers(struct task_struct *curr, - struct task_struct *next) -{ -} - -#endif /* CONFIG_PREEMPT_NOTIFIERS */ - -/** - * prepare_task_switch - prepare to switch tasks - * @rq: the runqueue preparing to switch - * @prev: the current task that is being switched out - * @next: the task we are going to switch to. - * - * This is called with the rq lock held and interrupts off. It must - * be paired with a subsequent finish_task_switch after the context - * switch. - * - * prepare_task_switch sets up locking and calls architecture specific - * hooks. - */ -static inline void -prepare_task_switch(struct rq *rq, struct task_struct *prev, - struct task_struct *next) -{ - fire_sched_out_preempt_notifiers(prev, next); - prepare_lock_switch(rq, next); - prepare_arch_switch(next); -} - -/** - * finish_task_switch - clean up after a task-switch - * @rq: runqueue associated with task-switch - * @prev: the thread we just switched away from. - * - * finish_task_switch must be called after the context switch, paired - * with a prepare_task_switch call before the context switch. - * finish_task_switch will reconcile locking set up by prepare_task_switch, - * and do any other architecture-specific cleanup actions. - * - * Note that we may have delayed dropping an mm in context_switch(). If - * so, we finish that here outside of the runqueue lock. (Doing it - * with the lock held can cause deadlocks; see schedule() for - * details.) - */ -static void finish_task_switch(struct rq *rq, struct task_struct *prev) - __releases(rq->lock) -{ - struct mm_struct *mm = rq->prev_mm; - long prev_state; -#ifdef CONFIG_SMP - int post_schedule = 0; - - if (current->sched_class->needs_post_schedule) - post_schedule = current->sched_class->needs_post_schedule(rq); -#endif - - rq->prev_mm = NULL; - - /* - * A task struct has one reference for the use as "current". - * If a task dies, then it sets TASK_DEAD in tsk->state and calls - * schedule one last time. The schedule call will never return, and - * the scheduled task must drop that reference. - * The test for TASK_DEAD must occur while the runqueue locks are - * still held, otherwise prev could be scheduled on another cpu, die - * there before we look at prev->state, and then the reference would - * be dropped twice. - * Manfred Spraul <manfred@colorfullife.com> - */ - prev_state = prev->state; - finish_arch_switch(prev); - finish_lock_switch(rq, prev); -#ifdef CONFIG_SMP - if (post_schedule) - current->sched_class->post_schedule(rq); -#endif - - fire_sched_in_preempt_notifiers(current); - if (mm) - mmdrop(mm); - if (unlikely(prev_state == TASK_DEAD)) { - /* - * Remove function-return probe instances associated with this - * task and put them back on the free list. - */ - kprobe_flush_task(prev); - put_task_struct(prev); - } -} - -/** - * schedule_tail - first thing a freshly forked thread must call. - * @prev: the thread we just switched away from. - */ -asmlinkage void schedule_tail(struct task_struct *prev) - __releases(rq->lock) -{ - struct rq *rq = this_rq(); - - finish_task_switch(rq, prev); -#ifdef __ARCH_WANT_UNLOCKED_CTXSW - /* In this case, finish_task_switch does not reenable preemption */ - preempt_enable(); -#endif - if (current->set_child_tid) - put_user(task_pid_vnr(current), current->set_child_tid); -} - -/* - * context_switch - switch to the new MM and the new - * thread's register state. - */ -static inline void -context_switch(struct rq *rq, struct task_struct *prev, - struct task_struct *next) -{ - struct mm_struct *mm, *oldmm; - - prepare_task_switch(rq, prev, next); - trace_sched_switch(rq, prev, next); - mm = next->mm; - oldmm = prev->active_mm; - /* - * For paravirt, this is coupled with an exit in switch_to to - * combine the page table reload and the switch backend into - * one hypercall. - */ - arch_enter_lazy_cpu_mode(); - - if (unlikely(!mm)) { - next->active_mm = oldmm; - atomic_inc(&oldmm->mm_count); - enter_lazy_tlb(oldmm, next); - } else - switch_mm(oldmm, mm, next); - - if (unlikely(!prev->mm)) { - prev->active_mm = NULL; - rq->prev_mm = oldmm; - } - /* - * Since the runqueue lock will be released by the next - * task (which is an invalid locking op but in the case - * of the scheduler it's an obvious special-case), so we - * do an early lockdep release here: - */ -#ifndef __ARCH_WANT_UNLOCKED_CTXSW - spin_release(&rq->lock.dep_map, 1, _THIS_IP_); -#endif - - /* Here we just switch the register state and the stack. */ - switch_to(prev, next, prev); - - barrier(); - /* - * this_rq must be evaluated again because prev may have moved - * CPUs since it called schedule(), thus the 'rq' on its stack - * frame will be invalid. - */ - finish_task_switch(this_rq(), prev); -} - -/* - * nr_running, nr_uninterruptible and nr_context_switches: - * - * externally visible scheduler statistics: current number of runnable - * threads, current number of uninterruptible-sleeping threads, total - * number of context switches performed since bootup. - */ -unsigned long nr_running(void) -{ - unsigned long i, sum = 0; - - for_each_online_cpu(i) - sum += cpu_rq(i)->nr_running; - - return sum; -} - -unsigned long nr_uninterruptible(void) -{ - unsigned long i, sum = 0; - - for_each_possible_cpu(i) - sum += cpu_rq(i)->nr_uninterruptible; - - /* - * Since we read the counters lockless, it might be slightly - * inaccurate. Do not allow it to go below zero though: - */ - if (unlikely((long)sum < 0)) - sum = 0; - - return sum; -} - -unsigned long long nr_context_switches(void) -{ - int i; - unsigned long long sum = 0; - - for_each_possible_cpu(i) - sum += cpu_rq(i)->nr_switches; - - return sum; -} - -unsigned long nr_iowait(void) -{ - unsigned long i, sum = 0; - - for_each_possible_cpu(i) - sum += atomic_read(&cpu_rq(i)->nr_iowait); - - return sum; -} - -unsigned long nr_active(void) -{ - unsigned long i, running = 0, uninterruptible = 0; - - for_each_online_cpu(i) { - running += cpu_rq(i)->nr_running; - uninterruptible += cpu_rq(i)->nr_uninterruptible; - } - - if (unlikely((long)uninterruptible < 0)) - uninterruptible = 0; - - return running + uninterruptible; -} - -/* - * Update rq->cpu_load[] statistics. This function is usually called every - * scheduler tick (TICK_NSEC). - */ -static void update_cpu_load(struct rq *this_rq) -{ - unsigned long this_load = this_rq->load.weight; - int i, scale; - - this_rq->nr_load_updates++; - - /* Update our load: */ - for (i = 0, scale = 1; i < CPU_LOAD_IDX_MAX; i++, scale += scale) { - unsigned long old_load, new_load; - - /* scale is effectively 1 << i now, and >> i divides by scale */ - - old_load = this_rq->cpu_load[i]; - new_load = this_load; - /* - * Round up the averaging division if load is increasing. This - * prevents us from getting stuck on 9 if the load is 10, for - * example. - */ - if (new_load > old_load) - new_load += scale-1; - this_rq->cpu_load[i] = (old_load*(scale-1) + new_load) >> i; - } -} - -#ifdef CONFIG_SMP - -/* - * double_rq_lock - safely lock two runqueues - * - * Note this does not disable interrupts like task_rq_lock, - * you need to do so manually before calling. - */ -static void double_rq_lock(struct rq *rq1, struct rq *rq2) - __acquires(rq1->lock) - __acquires(rq2->lock) -{ - BUG_ON(!irqs_disabled()); - if (rq1 == rq2) { - spin_lock(&rq1->lock); - __acquire(rq2->lock); /* Fake it out ;) */ - } else { - if (rq1 < rq2) { - spin_lock(&rq1->lock); - spin_lock_nested(&rq2->lock, SINGLE_DEPTH_NESTING); - } else { - spin_lock(&rq2->lock); - spin_lock_nested(&rq1->lock, SINGLE_DEPTH_NESTING); - } - } - update_rq_clock(rq1); - update_rq_clock(rq2); -} - -/* - * double_rq_unlock - safely unlock two runqueues - * - * Note this does not restore interrupts like task_rq_unlock, - * you need to do so manually after calling. - */ -static void double_rq_unlock(struct rq *rq1, struct rq *rq2) - __releases(rq1->lock) - __releases(rq2->lock) -{ - spin_unlock(&rq1->lock); - if (rq1 != rq2) - spin_unlock(&rq2->lock); - else - __release(rq2->lock); -} - -/* - * If dest_cpu is allowed for this process, migrate the task to it. - * This is accomplished by forcing the cpu_allowed mask to only - * allow dest_cpu, which will force the cpu onto dest_cpu. Then - * the cpu_allowed mask is restored. - */ -static void sched_migrate_task(struct task_struct *p, int dest_cpu) -{ - struct migration_req req; - unsigned long flags; - struct rq *rq; - - rq = task_rq_lock(p, &flags); - if (!cpumask_test_cpu(dest_cpu, &p->cpus_allowed) - || unlikely(!cpu_active(dest_cpu))) - goto out; - - /* force the process onto the specified CPU */ - if (migrate_task(p, dest_cpu, &req)) { - /* Need to wait for migration thread (might exit: take ref). */ - struct task_struct *mt = rq->migration_thread; - - get_task_struct(mt); - task_rq_unlock(rq, &flags); - wake_up_process(mt); - put_task_struct(mt); - wait_for_completion(&req.done); - - return; - } -out: - task_rq_unlock(rq, &flags); -} - -/* - * sched_exec - execve() is a valuable balancing opportunity, because at - * this point the task has the smallest effective memory and cache footprint. - */ -void sched_exec(void) -{ - int new_cpu, this_cpu = get_cpu(); - new_cpu = sched_balance_self(this_cpu, SD_BALANCE_EXEC); - put_cpu(); - if (new_cpu != this_cpu) - sched_migrate_task(current, new_cpu); -} - -/* - * pull_task - move a task from a remote runqueue to the local runqueue. - * Both runqueues must be locked. - */ -static void pull_task(struct rq *src_rq, struct task_struct *p, - struct rq *this_rq, int this_cpu) -{ - deactivate_task(src_rq, p, 0); - set_task_cpu(p, this_cpu); - activate_task(this_rq, p, 0); - /* - * Note that idle threads have a prio of MAX_PRIO, for this test - * to be always true for them. - */ - check_preempt_curr(this_rq, p, 0); -} - -/* - * can_migrate_task - may task p from runqueue rq be migrated to this_cpu? - */ -static -int can_migrate_task(struct task_struct *p, struct rq *rq, int this_cpu, - struct sched_domain *sd, enum cpu_idle_type idle, - int *all_pinned) -{ - int tsk_cache_hot = 0; - /* - * We do not migrate tasks that are: - * 1) running (obviously), or - * 2) cannot be migrated to this CPU due to cpus_allowed, or - * 3) are cache-hot on their current CPU. - */ - if (!cpumask_test_cpu(this_cpu, &p->cpus_allowed)) { - schedstat_inc(p, se.nr_failed_migrations_affine); - return 0; - } - *all_pinned = 0; - - if (task_running(rq, p)) { - schedstat_inc(p, se.nr_failed_migrations_running); - return 0; - } - - /* - * Aggressive migration if: - * 1) task is cache cold, or - * 2) too many balance attempts have failed. - */ - - tsk_cache_hot = task_hot(p, rq->clock, sd); - if (!tsk_cache_hot || - sd->nr_balance_failed > sd->cache_nice_tries) { -#ifdef CONFIG_SCHEDSTATS - if (tsk_cache_hot) { - schedstat_inc(sd, lb_hot_gained[idle]); - schedstat_inc(p, se.nr_forced_migrations); - } -#endif - return 1; - } - - if (tsk_cache_hot) { - schedstat_inc(p, se.nr_failed_migrations_hot); - return 0; - } - return 1; -} - -static unsigned long -balance_tasks(struct rq *this_rq, int this_cpu, struct rq *busiest, - unsigned long max_load_move, struct sched_domain *sd, - enum cpu_idle_type idle, int *all_pinned, - int *this_best_prio, struct rq_iterator *iterator) -{ - int loops = 0, pulled = 0, pinned = 0; - struct task_struct *p; - long rem_load_move = max_load_move; - - if (max_load_move == 0) - goto out; - - pinned = 1; - - /* - * Start the load-balancing iterator: - */ - p = iterator->start(iterator->arg); -next: - if (!p || loops++ > sysctl_sched_nr_migrate) - goto out; - - if ((p->se.load.weight >> 1) > rem_load_move || - !can_migrate_task(p, busiest, this_cpu, sd, idle, &pinned)) { - p = iterator->next(iterator->arg); - goto next; - } - - pull_task(busiest, p, this_rq, this_cpu); - pulled++; - rem_load_move -= p->se.load.weight; - -#ifdef CONFIG_PREEMPT - /* - * NEWIDLE balancing is a source of latency, so preemptible kernels - * will stop after the first task is pulled to minimize the critical - * section. - */ - if (idle == CPU_NEWLY_IDLE) - goto out; -#endif - - /* - * We only want to steal up to the prescribed amount of weighted load. - */ - if (rem_load_move > 0) { - if (p->prio < *this_best_prio) - *this_best_prio = p->prio; - p = iterator->next(iterator->arg); - goto next; - } -out: - /* - * Right now, this is one of only two places pull_task() is called, - * so we can safely collect pull_task() stats here rather than - * inside pull_task(). - */ - schedstat_add(sd, lb_gained[idle], pulled); - - if (all_pinned) - *all_pinned = pinned; - - return max_load_move - rem_load_move; -} - -/* - * move_tasks tries to move up to max_load_move weighted load from busiest to - * this_rq, as part of a balancing operation within domain "sd". - * Returns 1 if successful and 0 otherwise. - * - * Called with both runqueues locked. - */ -static int move_tasks(struct rq *this_rq, int this_cpu, struct rq *busiest, - unsigned long max_load_move, - struct sched_domain *sd, enum cpu_idle_type idle, - int *all_pinned) -{ - const struct sched_class *class = sched_class_highest; - unsigned long total_load_moved = 0; - int this_best_prio = this_rq->curr->prio; - - do { - total_load_moved += - class->load_balance(this_rq, this_cpu, busiest, - max_load_move - total_load_moved, - sd, idle, all_pinned, &this_best_prio); - class = class->next; - -#ifdef CONFIG_PREEMPT - /* - * NEWIDLE balancing is a source of latency, so preemptible - * kernels will stop after the first task is pulled to minimize - * the critical section. - */ - if (idle == CPU_NEWLY_IDLE && this_rq->nr_running) - break; -#endif - } while (class && max_load_move > total_load_moved); - - return total_load_moved > 0; -} - -static int -iter_move_one_task(struct rq *this_rq, int this_cpu, struct rq *busiest, - struct sched_domain *sd, enum cpu_idle_type idle, - struct rq_iterator *iterator) -{ - struct task_struct *p = iterator->start(iterator->arg); - int pinned = 0; - - while (p) { - if (can_migrate_task(p, busiest, this_cpu, sd, idle, &pinned)) { - pull_task(busiest, p, this_rq, this_cpu); - /* - * Right now, this is only the second place pull_task() - * is called, so we can safely collect pull_task() - * stats here rather than inside pull_task(). - */ - schedstat_inc(sd, lb_gained[idle]); - - return 1; - } - p = iterator->next(iterator->arg); - } - - return 0; -} - -/* - * move_one_task tries to move exactly one task from busiest to this_rq, as - * part of active balancing operations within "domain". - * Returns 1 if successful and 0 otherwise. - * - * Called with both runqueues locked. - */ -static int move_one_task(struct rq *this_rq, int this_cpu, struct rq *busiest, - struct sched_domain *sd, enum cpu_idle_type idle) -{ - const struct sched_class *class; - - for (class = sched_class_highest; class; class = class->next) - if (class->move_one_task(this_rq, this_cpu, busiest, sd, idle)) - return 1; - - return 0; -} -/********** Helpers for find_busiest_group ************************/ -/* - * sd_lb_stats - Structure to store the statistics of a sched_domain - * during load balancing. - */ -struct sd_lb_stats { - struct sched_group *busiest; /* Busiest group in this sd */ - struct sched_group *this; /* Local group in this sd */ - unsigned long total_load; /* Total load of all groups in sd */ - unsigned long total_pwr; /* Total power of all groups in sd */ - unsigned long avg_load; /* Average load across all groups in sd */ - - /** Statistics of this group */ - unsigned long this_load; - unsigned long this_load_per_task; - unsigned long this_nr_running; - - /* Statistics of the busiest group */ - unsigned long max_load; - unsigned long busiest_load_per_task; - unsigned long busiest_nr_running; - - int group_imb; /* Is there imbalance in this sd */ -#if defined(CONFIG_SCHED_MC) || defined(CONFIG_SCHED_SMT) - int power_savings_balance; /* Is powersave balance needed for this sd */ - struct sched_group *group_min; /* Least loaded group in sd */ - struct sched_group *group_leader; /* Group which relieves group_min */ - unsigned long min_load_per_task; /* load_per_task in group_min */ - unsigned long leader_nr_running; /* Nr running of group_leader */ - unsigned long min_nr_running; /* Nr running of group_min */ -#endif -}; - -/* - * sg_lb_stats - stats of a sched_group required for load_balancing - */ -struct sg_lb_stats { - unsigned long avg_load; /*Avg load across the CPUs of the group */ - unsigned long group_load; /* Total load over the CPUs of the group */ - unsigned long sum_nr_running; /* Nr tasks running in the group */ - unsigned long sum_weighted_load; /* Weighted load of group's tasks */ - unsigned long group_capacity; - int group_imb; /* Is there an imbalance in the group ? */ -}; - -/** - * group_first_cpu - Returns the first cpu in the cpumask of a sched_group. - * @group: The group whose first cpu is to be returned. - */ -static inline unsigned int group_first_cpu(struct sched_group *group) -{ - return cpumask_first(sched_group_cpus(group)); -} - -/** - * get_sd_load_idx - Obtain the load index for a given sched domain. - * @sd: The sched_domain whose load_idx is to be obtained. - * @idle: The Idle status of the CPU for whose sd load_icx is obtained. - */ -static inline int get_sd_load_idx(struct sched_domain *sd, - enum cpu_idle_type idle) -{ - int load_idx; - - switch (idle) { - case CPU_NOT_IDLE: - load_idx = sd->busy_idx; - break; - - case CPU_NEWLY_IDLE: - load_idx = sd->newidle_idx; - break; - default: - load_idx = sd->idle_idx; - break; - } - - return load_idx; -} - - -#if defined(CONFIG_SCHED_MC) || defined(CONFIG_SCHED_SMT) -/** - * init_sd_power_savings_stats - Initialize power savings statistics for - * the given sched_domain, during load balancing. - * - * @sd: Sched domain whose power-savings statistics are to be initialized. - * @sds: Variable containing the statistics for sd. - * @idle: Idle status of the CPU at which we're performing load-balancing. - */ -static inline void init_sd_power_savings_stats(struct sched_domain *sd, - struct sd_lb_stats *sds, enum cpu_idle_type idle) -{ - /* - * Busy processors will not participate in power savings - * balance. - */ - if (idle == CPU_NOT_IDLE || !(sd->flags & SD_POWERSAVINGS_BALANCE)) - sds->power_savings_balance = 0; - else { - sds->power_savings_balance = 1; - sds->min_nr_running = ULONG_MAX; - sds->leader_nr_running = 0; - } -} - -/** - * update_sd_power_savings_stats - Update the power saving stats for a - * sched_domain while performing load balancing. - * - * @group: sched_group belonging to the sched_domain under consideration. - * @sds: Variable containing the statistics of the sched_domain - * @local_group: Does group contain the CPU for which we're performing - * load balancing ? - * @sgs: Variable containing the statistics of the group. - */ -static inline void update_sd_power_savings_stats(struct sched_group *group, - struct sd_lb_stats *sds, int local_group, struct sg_lb_stats *sgs) -{ - - if (!sds->power_savings_balance) - return; - - /* - * If the local group is idle or completely loaded - * no need to do power savings balance at this domain - */ - if (local_group && (sds->this_nr_running >= sgs->group_capacity || - !sds->this_nr_running)) - sds->power_savings_balance = 0; - - /* - * If a group is already running at full capacity or idle, - * don't include that group in power savings calculations - */ - if (!sds->power_savings_balance || - sgs->sum_nr_running >= sgs->group_capacity || - !sgs->sum_nr_running) - return; - - /* - * Calculate the group which has the least non-idle load. - * This is the group from where we need to pick up the load - * for saving power - */ - if ((sgs->sum_nr_running < sds->min_nr_running) || - (sgs->sum_nr_running == sds->min_nr_running && - group_first_cpu(group) > group_first_cpu(sds->group_min))) { - sds->group_min = group; - sds->min_nr_running = sgs->sum_nr_running; - sds->min_load_per_task = sgs->sum_weighted_load / - sgs->sum_nr_running; - } - - /* - * Calculate the group which is almost near its - * capacity but still has some space to pick up some load - * from other group and save more power - */ - if (sgs->sum_nr_running > sgs->group_capacity - 1) - return; - - if (sgs->sum_nr_running > sds->leader_nr_running || - (sgs->sum_nr_running == sds->leader_nr_running && - group_first_cpu(group) < group_first_cpu(sds->group_leader))) { - sds->group_leader = group; - sds->leader_nr_running = sgs->sum_nr_running; - } -} - -/** - * check_power_save_busiest_group - see if there is potential for some power-savings balance - * @sds: Variable containing the statistics of the sched_domain - * under consideration. - * @this_cpu: Cpu at which we're currently performing load-balancing. - * @imbalance: Variable to store the imbalance. - * - * Description: - * Check if we have potential to perform some power-savings balance. - * If yes, set the busiest group to be the least loaded group in the - * sched_domain, so that it's CPUs can be put to idle. - * - * Returns 1 if there is potential to perform power-savings balance. - * Else returns 0. - */ -static inline int check_power_save_busiest_group(struct sd_lb_stats *sds, - int this_cpu, unsigned long *imbalance) -{ - if (!sds->power_savings_balance) - return 0; - - if (sds->this != sds->group_leader || - sds->group_leader == sds->group_min) - return 0; - - *imbalance = sds->min_load_per_task; - sds->busiest = sds->group_min; - - if (sched_mc_power_savings >= POWERSAVINGS_BALANCE_WAKEUP) { - cpu_rq(this_cpu)->rd->sched_mc_preferred_wakeup_cpu = - group_first_cpu(sds->group_leader); - } - - return 1; - -} -#else /* CONFIG_SCHED_MC || CONFIG_SCHED_SMT */ -static inline void init_sd_power_savings_stats(struct sched_domain *sd, - struct sd_lb_stats *sds, enum cpu_idle_type idle) -{ - return; -} - -static inline void update_sd_power_savings_stats(struct sched_group *group, - struct sd_lb_stats *sds, int local_group, struct sg_lb_stats *sgs) -{ - return; -} - -static inline int check_power_save_busiest_group(struct sd_lb_stats *sds, - int this_cpu, unsigned long *imbalance) -{ - return 0; -} -#endif /* CONFIG_SCHED_MC || CONFIG_SCHED_SMT */ - - -/** - * update_sg_lb_stats - Update sched_group's statistics for load balancing. - * @group: sched_group whose statistics are to be updated. - * @this_cpu: Cpu for which load balance is currently performed. - * @idle: Idle status of this_cpu - * @load_idx: Load index of sched_domain of this_cpu for load calc. - * @sd_idle: Idle status of the sched_domain containing group. - * @local_group: Does group contain this_cpu. - * @cpus: Set of cpus considered for load balancing. - * @balance: Should we balance. - * @sgs: variable to hold the statistics for this group. - */ -static inline void update_sg_lb_stats(struct sched_group *group, int this_cpu, - enum cpu_idle_type idle, int load_idx, int *sd_idle, - int local_group, const struct cpumask *cpus, - int *balance, struct sg_lb_stats *sgs) -{ - unsigned long load, max_cpu_load, min_cpu_load; - int i; - unsigned int balance_cpu = -1, first_idle_cpu = 0; - unsigned long sum_avg_load_per_task; - unsigned long avg_load_per_task; - - if (local_group) - balance_cpu = group_first_cpu(group); - - /* Tally up the load of all CPUs in the group */ - sum_avg_load_per_task = avg_load_per_task = 0; - max_cpu_load = 0; - min_cpu_load = ~0UL; - - for_each_cpu_and(i, sched_group_cpus(group), cpus) { - struct rq *rq = cpu_rq(i); - - if (*sd_idle && rq->nr_running) - *sd_idle = 0; - - /* Bias balancing toward cpus of our domain */ - if (local_group) { - if (idle_cpu(i) && !first_idle_cpu) { - first_idle_cpu = 1; - balance_cpu = i; - } - - load = target_load(i, load_idx); - } else { - load = source_load(i, load_idx); - if (load > max_cpu_load) - max_cpu_load = load; - if (min_cpu_load > load) - min_cpu_load = load; - } - - sgs->group_load += load; - sgs->sum_nr_running += rq->nr_running; - sgs->sum_weighted_load += weighted_cpuload(i); - - sum_avg_load_per_task += cpu_avg_load_per_task(i); - } - - /* - * First idle cpu or the first cpu(busiest) in this sched group - * is eligible for doing load balancing at this and above - * domains. In the newly idle case, we will allow all the cpu's - * to do the newly idle load balance. - */ - if (idle != CPU_NEWLY_IDLE && local_group && - balance_cpu != this_cpu && balance) { - *balance = 0; - return; - } - - /* Adjust by relative CPU power of the group */ - sgs->avg_load = sg_div_cpu_power(group, - sgs->group_load * SCHED_LOAD_SCALE); - - - /* - * Consider the group unbalanced when the imbalance is larger - * than the average weight of two tasks. - * - * APZ: with cgroup the avg task weight can vary wildly and - * might not be a suitable number - should we keep a - * normalized nr_running number somewhere that negates - * the hierarchy? - */ - avg_load_per_task = sg_div_cpu_power(group, - sum_avg_load_per_task * SCHED_LOAD_SCALE); - - if ((max_cpu_load - min_cpu_load) > 2*avg_load_per_task) - sgs->group_imb = 1; - - sgs->group_capacity = group->__cpu_power / SCHED_LOAD_SCALE; - -} - -/** - * update_sd_lb_stats - Update sched_group's statistics for load balancing. - * @sd: sched_domain whose statistics are to be updated. - * @this_cpu: Cpu for which load balance is currently performed. - * @idle: Idle status of this_cpu - * @sd_idle: Idle status of the sched_domain containing group. - * @cpus: Set of cpus considered for load balancing. - * @balance: Should we balance. - * @sds: variable to hold the statistics for this sched_domain. - */ -static inline void update_sd_lb_stats(struct sched_domain *sd, int this_cpu, - enum cpu_idle_type idle, int *sd_idle, - const struct cpumask *cpus, int *balance, - struct sd_lb_stats *sds) -{ - struct sched_group *group = sd->groups; - struct sg_lb_stats sgs; - int load_idx; - - init_sd_power_savings_stats(sd, sds, idle); - load_idx = get_sd_load_idx(sd, idle); - - do { - int local_group; - - local_group = cpumask_test_cpu(this_cpu, - sched_group_cpus(group)); - memset(&sgs, 0, sizeof(sgs)); - update_sg_lb_stats(group, this_cpu, idle, load_idx, sd_idle, - local_group, cpus, balance, &sgs); - - if (local_group && balance && !(*balance)) - return; - - sds->total_load += sgs.group_load; - sds->total_pwr += group->__cpu_power; - - if (local_group) { - sds->this_load = sgs.avg_load; - sds->this = group; - sds->this_nr_running = sgs.sum_nr_running; - sds->this_load_per_task = sgs.sum_weighted_load; - } else if (sgs.avg_load > sds->max_load && - (sgs.sum_nr_running > sgs.group_capacity || - sgs.group_imb)) { - sds->max_load = sgs.avg_load; - sds->busiest = group; - sds->busiest_nr_running = sgs.sum_nr_running; - sds->busiest_load_per_task = sgs.sum_weighted_load; - sds->group_imb = sgs.group_imb; - } - - update_sd_power_savings_stats(group, sds, local_group, &sgs); - group = group->next; - } while (group != sd->groups); - -} - -/** - * fix_small_imbalance - Calculate the minor imbalance that exists - * amongst the groups of a sched_domain, during - * load balancing. - * @sds: Statistics of the sched_domain whose imbalance is to be calculated. - * @this_cpu: The cpu at whose sched_domain we're performing load-balance. - * @imbalance: Variable to store the imbalance. - */ -static inline void fix_small_imbalance(struct sd_lb_stats *sds, - int this_cpu, unsigned long *imbalance) -{ - unsigned long tmp, pwr_now = 0, pwr_move = 0; - unsigned int imbn = 2; - - if (sds->this_nr_running) { - sds->this_load_per_task /= sds->this_nr_running; - if (sds->busiest_load_per_task > - sds->this_load_per_task) - imbn = 1; - } else - sds->this_load_per_task = - cpu_avg_load_per_task(this_cpu); - - if (sds->max_load - sds->this_load + sds->busiest_load_per_task >= - sds->busiest_load_per_task * imbn) { - *imbalance = sds->busiest_load_per_task; - return; - } - - /* - * OK, we don't have enough imbalance to justify moving tasks, - * however we may be able to increase total CPU power used by - * moving them. - */ - - pwr_now += sds->busiest->__cpu_power * - min(sds->busiest_load_per_task, sds->max_load); - pwr_now += sds->this->__cpu_power * - min(sds->this_load_per_task, sds->this_load); - pwr_now /= SCHED_LOAD_SCALE; - - /* Amount of load we'd subtract */ - tmp = sg_div_cpu_power(sds->busiest, - sds->busiest_load_per_task * SCHED_LOAD_SCALE); - if (sds->max_load > tmp) - pwr_move += sds->busiest->__cpu_power * - min(sds->busiest_load_per_task, sds->max_load - tmp); - - /* Amount of load we'd add */ - if (sds->max_load * sds->busiest->__cpu_power < - sds->busiest_load_per_task * SCHED_LOAD_SCALE) - tmp = sg_div_cpu_power(sds->this, - sds->max_load * sds->busiest->__cpu_power); - else - tmp = sg_div_cpu_power(sds->this, - sds->busiest_load_per_task * SCHED_LOAD_SCALE); - pwr_move += sds->this->__cpu_power * - min(sds->this_load_per_task, sds->this_load + tmp); - pwr_move /= SCHED_LOAD_SCALE; - - /* Move if we gain throughput */ - if (pwr_move > pwr_now) - *imbalance = sds->busiest_load_per_task; -} - -/** - * calculate_imbalance - Calculate the amount of imbalance present within the - * groups of a given sched_domain during load balance. - * @sds: statistics of the sched_domain whose imbalance is to be calculated. - * @this_cpu: Cpu for which currently load balance is being performed. - * @imbalance: The variable to store the imbalance. - */ -static inline void calculate_imbalance(struct sd_lb_stats *sds, int this_cpu, - unsigned long *imbalance) -{ - unsigned long max_pull; - /* - * In the presence of smp nice balancing, certain scenarios can have - * max load less than avg load(as we skip the groups at or below - * its cpu_power, while calculating max_load..) - */ - if (sds->max_load < sds->avg_load) { - *imbalance = 0; - return fix_small_imbalance(sds, this_cpu, imbalance); - } - - /* Don't want to pull so many tasks that a group would go idle */ - max_pull = min(sds->max_load - sds->avg_load, - sds->max_load - sds->busiest_load_per_task); - - /* How much load to actually move to equalise the imbalance */ - *imbalance = min(max_pull * sds->busiest->__cpu_power, - (sds->avg_load - sds->this_load) * sds->this->__cpu_power) - / SCHED_LOAD_SCALE; - - /* - * if *imbalance is less than the average load per runnable task - * there is no gaurantee that any tasks will be moved so we'll have - * a think about bumping its value to force at least one task to be - * moved - */ - if (*imbalance < sds->busiest_load_per_task) - return fix_small_imbalance(sds, this_cpu, imbalance); - -} -/******* find_busiest_group() helpers end here *********************/ - -/** - * find_busiest_group - Returns the busiest group within the sched_domain - * if there is an imbalance. If there isn't an imbalance, and - * the user has opted for power-savings, it returns a group whose - * CPUs can be put to idle by rebalancing those tasks elsewhere, if - * such a group exists. - * - * Also calculates the amount of weighted load which should be moved - * to restore balance. - * - * @sd: The sched_domain whose busiest group is to be returned. - * @this_cpu: The cpu for which load balancing is currently being performed. - * @imbalance: Variable which stores amount of weighted load which should - * be moved to restore balance/put a group to idle. - * @idle: The idle status of this_cpu. - * @sd_idle: The idleness of sd - * @cpus: The set of CPUs under consideration for load-balancing. - * @balance: Pointer to a variable indicating if this_cpu - * is the appropriate cpu to perform load balancing at this_level. - * - * Returns: - the busiest group if imbalance exists. - * - If no imbalance and user has opted for power-savings balance, - * return the least loaded group whose CPUs can be - * put to idle by rebalancing its tasks onto our group. - */ -static struct sched_group * -find_busiest_group(struct sched_domain *sd, int this_cpu, - unsigned long *imbalance, enum cpu_idle_type idle, - int *sd_idle, const struct cpumask *cpus, int *balance) -{ - struct sd_lb_stats sds; - - memset(&sds, 0, sizeof(sds)); - - /* - * Compute the various statistics relavent for load balancing at - * this level. - */ - update_sd_lb_stats(sd, this_cpu, idle, sd_idle, cpus, - balance, &sds); - - /* Cases where imbalance does not exist from POV of this_cpu */ - /* 1) this_cpu is not the appropriate cpu to perform load balancing - * at this level. - * 2) There is no busy sibling group to pull from. - * 3) This group is the busiest group. - * 4) This group is more busy than the avg busieness at this - * sched_domain. - * 5) The imbalance is within the specified limit. - * 6) Any rebalance would lead to ping-pong - */ - if (balance && !(*balance)) - goto ret; - - if (!sds.busiest || sds.busiest_nr_running == 0) - goto out_balanced; - - if (sds.this_load >= sds.max_load) - goto out_balanced; - - sds.avg_load = (SCHED_LOAD_SCALE * sds.total_load) / sds.total_pwr; - - if (sds.this_load >= sds.avg_load) - goto out_balanced; - - if (100 * sds.max_load <= sd->imbalance_pct * sds.this_load) - goto out_balanced; - - sds.busiest_load_per_task /= sds.busiest_nr_running; - if (sds.group_imb) - sds.busiest_load_per_task = - min(sds.busiest_load_per_task, sds.avg_load); - - /* - * We're trying to get all the cpus to the average_load, so we don't - * want to push ourselves above the average load, nor do we wish to - * reduce the max loaded cpu below the average load, as either of these - * actions would just result in more rebalancing later, and ping-pong - * tasks around. Thus we look for the minimum possible imbalance. - * Negative imbalances (*we* are more loaded than anyone else) will - * be counted as no imbalance for these purposes -- we can't fix that - * by pulling tasks to us. Be careful of negative numbers as they'll - * appear as very large values with unsigned longs. - */ - if (sds.max_load <= sds.busiest_load_per_task) - goto out_balanced; - - /* Looks like there is an imbalance. Compute it */ - calculate_imbalance(&sds, this_cpu, imbalance); - return sds.busiest; - -out_balanced: - /* - * There is no obvious imbalance. But check if we can do some balancing - * to save power. - */ - if (check_power_save_busiest_group(&sds, this_cpu, imbalance)) - return sds.busiest; -ret: - *imbalance = 0; - return NULL; -} - -/* - * find_busiest_queue - find the busiest runqueue among the cpus in group. - */ -static struct rq * -find_busiest_queue(struct sched_group *group, enum cpu_idle_type idle, - unsigned long imbalance, const struct cpumask *cpus) -{ - struct rq *busiest = NULL, *rq; - unsigned long max_load = 0; - int i; - - for_each_cpu(i, sched_group_cpus(group)) { - unsigned long wl; - - if (!cpumask_test_cpu(i, cpus)) - continue; - - rq = cpu_rq(i); - wl = weighted_cpuload(i); - - if (rq->nr_running == 1 && wl > imbalance) - continue; - - if (wl > max_load) { - max_load = wl; - busiest = rq; - } - } - - return busiest; -} - -/* - * Max backoff if we encounter pinned tasks. Pretty arbitrary value, but - * so long as it is large enough. - */ -#define MAX_PINNED_INTERVAL 512 - -/* Working cpumask for load_balance and load_balance_newidle. */ -static DEFINE_PER_CPU(cpumask_var_t, load_balance_tmpmask); - -/* - * Check this_cpu to ensure it is balanced within domain. Attempt to move - * tasks if there is an imbalance. - */ -static int load_balance(int this_cpu, struct rq *this_rq, - struct sched_domain *sd, enum cpu_idle_type idle, - int *balance) -{ - int ld_moved, all_pinned = 0, active_balance = 0, sd_idle = 0; - struct sched_group *group; - unsigned long imbalance; - struct rq *busiest; - unsigned long flags; - struct cpumask *cpus = __get_cpu_var(load_balance_tmpmask); - - cpumask_setall(cpus); - - /* - * When power savings policy is enabled for the parent domain, idle - * sibling can pick up load irrespective of busy siblings. In this case, - * let the state of idle sibling percolate up as CPU_IDLE, instead of - * portraying it as CPU_NOT_IDLE. - */ - if (idle != CPU_NOT_IDLE && sd->flags & SD_SHARE_CPUPOWER && - !test_sd_parent(sd, SD_POWERSAVINGS_BALANCE)) - sd_idle = 1; - - schedstat_inc(sd, lb_count[idle]); - -redo: - update_shares(sd); - group = find_busiest_group(sd, this_cpu, &imbalance, idle, &sd_idle, - cpus, balance); - - if (*balance == 0) - goto out_balanced; - - if (!group) { - schedstat_inc(sd, lb_nobusyg[idle]); - goto out_balanced; - } - - busiest = find_busiest_queue(group, idle, imbalance, cpus); - if (!busiest) { - schedstat_inc(sd, lb_nobusyq[idle]); - goto out_balanced; - } - - BUG_ON(busiest == this_rq); - - schedstat_add(sd, lb_imbalance[idle], imbalance); - - ld_moved = 0; - if (busiest->nr_running > 1) { - /* - * Attempt to move tasks. If find_busiest_group has found - * an imbalance but busiest->nr_running <= 1, the group is - * still unbalanced. ld_moved simply stays zero, so it is - * correctly treated as an imbalance. - */ - local_irq_save(flags); - double_rq_lock(this_rq, busiest); - ld_moved = move_tasks(this_rq, this_cpu, busiest, - imbalance, sd, idle, &all_pinned); - double_rq_unlock(this_rq, busiest); - local_irq_restore(flags); - - /* - * some other cpu did the load balance for us. - */ - if (ld_moved && this_cpu != smp_processor_id()) - resched_cpu(this_cpu); - - /* All tasks on this runqueue were pinned by CPU affinity */ - if (unlikely(all_pinned)) { - cpumask_clear_cpu(cpu_of(busiest), cpus); - if (!cpumask_empty(cpus)) - goto redo; - goto out_balanced; - } - } - - if (!ld_moved) { - schedstat_inc(sd, lb_failed[idle]); - sd->nr_balance_failed++; - - if (unlikely(sd->nr_balance_failed > sd->cache_nice_tries+2)) { - - spin_lock_irqsave(&busiest->lock, flags); - - /* don't kick the migration_thread, if the curr - * task on busiest cpu can't be moved to this_cpu - */ - if (!cpumask_test_cpu(this_cpu, - &busiest->curr->cpus_allowed)) { - spin_unlock_irqrestore(&busiest->lock, flags); - all_pinned = 1; - goto out_one_pinned; - } - - if (!busiest->active_balance) { - busiest->active_balance = 1; - busiest->push_cpu = this_cpu; - active_balance = 1; - } - spin_unlock_irqrestore(&busiest->lock, flags); - if (active_balance) - wake_up_process(busiest->migration_thread); - - /* - * We've kicked active balancing, reset the failure - * counter. - */ - sd->nr_balance_failed = sd->cache_nice_tries+1; - } - } else - sd->nr_balance_failed = 0; - - if (likely(!active_balance)) { - /* We were unbalanced, so reset the balancing interval */ - sd->balance_interval = sd->min_interval; - } else { - /* - * If we've begun active balancing, start to back off. This - * case may not be covered by the all_pinned logic if there - * is only 1 task on the busy runqueue (because we don't call - * move_tasks). - */ - if (sd->balance_interval < sd->max_interval) - sd->balance_interval *= 2; - } - - if (!ld_moved && !sd_idle && sd->flags & SD_SHARE_CPUPOWER && - !test_sd_parent(sd, SD_POWERSAVINGS_BALANCE)) - ld_moved = -1; - - goto out; - -out_balanced: - schedstat_inc(sd, lb_balanced[idle]); - - sd->nr_balance_failed = 0; - -out_one_pinned: - /* tune up the balancing interval */ - if ((all_pinned && sd->balance_interval < MAX_PINNED_INTERVAL) || - (sd->balance_interval < sd->max_interval)) - sd->balance_interval *= 2; - - if (!sd_idle && sd->flags & SD_SHARE_CPUPOWER && - !test_sd_parent(sd, SD_POWERSAVINGS_BALANCE)) - ld_moved = -1; - else - ld_moved = 0; -out: - if (ld_moved) - update_shares(sd); - return ld_moved; -} - -/* - * Check this_cpu to ensure it is balanced within domain. Attempt to move - * tasks if there is an imbalance. - * - * Called from schedule when this_rq is about to become idle (CPU_NEWLY_IDLE). - * this_rq is locked. - */ -static int -load_balance_newidle(int this_cpu, struct rq *this_rq, struct sched_domain *sd) -{ - struct sched_group *group; - struct rq *busiest = NULL; - unsigned long imbalance; - int ld_moved = 0; - int sd_idle = 0; - int all_pinned = 0; - struct cpumask *cpus = __get_cpu_var(load_balance_tmpmask); - - cpumask_setall(cpus); - - /* - * When power savings policy is enabled for the parent domain, idle - * sibling can pick up load irrespective of busy siblings. In this case, - * let the state of idle sibling percolate up as IDLE, instead of - * portraying it as CPU_NOT_IDLE. - */ - if (sd->flags & SD_SHARE_CPUPOWER && - !test_sd_parent(sd, SD_POWERSAVINGS_BALANCE)) - sd_idle = 1; - - schedstat_inc(sd, lb_count[CPU_NEWLY_IDLE]); -redo: - update_shares_locked(this_rq, sd); - group = find_busiest_group(sd, this_cpu, &imbalance, CPU_NEWLY_IDLE, - &sd_idle, cpus, NULL); - if (!group) { - schedstat_inc(sd, lb_nobusyg[CPU_NEWLY_IDLE]); - goto out_balanced; - } - - busiest = find_busiest_queue(group, CPU_NEWLY_IDLE, imbalance, cpus); - if (!busiest) { - schedstat_inc(sd, lb_nobusyq[CPU_NEWLY_IDLE]); - goto out_balanced; - } - - BUG_ON(busiest == this_rq); - - schedstat_add(sd, lb_imbalance[CPU_NEWLY_IDLE], imbalance); - - ld_moved = 0; - if (busiest->nr_running > 1) { - /* Attempt to move tasks */ - double_lock_balance(this_rq, busiest); - /* this_rq->clock is already updated */ - update_rq_clock(busiest); - ld_moved = move_tasks(this_rq, this_cpu, busiest, - imbalance, sd, CPU_NEWLY_IDLE, - &all_pinned); - double_unlock_balance(this_rq, busiest); - - if (unlikely(all_pinned)) { - cpumask_clear_cpu(cpu_of(busiest), cpus); - if (!cpumask_empty(cpus)) - goto redo; - } - } - - if (!ld_moved) { - int active_balance = 0; - - schedstat_inc(sd, lb_failed[CPU_NEWLY_IDLE]); - if (!sd_idle && sd->flags & SD_SHARE_CPUPOWER && - !test_sd_parent(sd, SD_POWERSAVINGS_BALANCE)) - return -1; - - if (sched_mc_power_savings < POWERSAVINGS_BALANCE_WAKEUP) - return -1; - - if (sd->nr_balance_failed++ < 2) - return -1; - - /* - * The only task running in a non-idle cpu can be moved to this - * cpu in an attempt to completely freeup the other CPU - * package. The same method used to move task in load_balance() - * have been extended for load_balance_newidle() to speedup - * consolidation at sched_mc=POWERSAVINGS_BALANCE_WAKEUP (2) - * - * The package power saving logic comes from - * find_busiest_group(). If there are no imbalance, then - * f_b_g() will return NULL. However when sched_mc={1,2} then - * f_b_g() will select a group from which a running task may be - * pulled to this cpu in order to make the other package idle. - * If there is no opportunity to make a package idle and if - * there are no imbalance, then f_b_g() will return NULL and no - * action will be taken in load_balance_newidle(). - * - * Under normal task pull operation due to imbalance, there - * will be more than one task in the source run queue and - * move_tasks() will succeed. ld_moved will be true and this - * active balance code will not be triggered. - */ - - /* Lock busiest in correct order while this_rq is held */ - double_lock_balance(this_rq, busiest); - - /* - * don't kick the migration_thread, if the curr - * task on busiest cpu can't be moved to this_cpu - */ - if (!cpumask_test_cpu(this_cpu, &busiest->curr->cpus_allowed)) { - double_unlock_balance(this_rq, busiest); - all_pinned = 1; - return ld_moved; - } - - if (!busiest->active_balance) { - busiest->active_balance = 1; - busiest->push_cpu = this_cpu; - active_balance = 1; - } - - double_unlock_balance(this_rq, busiest); - /* - * Should not call ttwu while holding a rq->lock - */ - spin_unlock(&this_rq->lock); - if (active_balance) - wake_up_process(busiest->migration_thread); - spin_lock(&this_rq->lock); - - } else - sd->nr_balance_failed = 0; - - update_shares_locked(this_rq, sd); - return ld_moved; - -out_balanced: - schedstat_inc(sd, lb_balanced[CPU_NEWLY_IDLE]); - if (!sd_idle && sd->flags & SD_SHARE_CPUPOWER && - !test_sd_parent(sd, SD_POWERSAVINGS_BALANCE)) - return -1; - sd->nr_balance_failed = 0; - - return 0; -} - -/* - * idle_balance is called by schedule() if this_cpu is about to become - * idle. Attempts to pull tasks from other CPUs. - */ -static void idle_balance(int this_cpu, struct rq *this_rq) -{ - struct sched_domain *sd; - int pulled_task = 0; - unsigned long next_balance = jiffies + HZ; - - for_each_domain(this_cpu, sd) { - unsigned long interval; - - if (!(sd->flags & SD_LOAD_BALANCE)) - continue; - - if (sd->flags & SD_BALANCE_NEWIDLE) - /* If we've pulled tasks over stop searching: */ - pulled_task = load_balance_newidle(this_cpu, this_rq, - sd); - - interval = msecs_to_jiffies(sd->balance_interval); - if (time_after(next_balance, sd->last_balance + interval)) - next_balance = sd->last_balance + interval; - if (pulled_task) - break; - } - if (pulled_task || time_after(jiffies, this_rq->next_balance)) { - /* - * We are going idle. next_balance may be set based on - * a busy processor. So reset next_balance. - */ - this_rq->next_balance = next_balance; - } -} - -/* - * active_load_balance is run by migration threads. It pushes running tasks - * off the busiest CPU onto idle CPUs. It requires at least 1 task to be - * running on each physical CPU where possible, and avoids physical / - * logical imbalances. - * - * Called with busiest_rq locked. - */ -static void active_load_balance(struct rq *busiest_rq, int busiest_cpu) -{ - int target_cpu = busiest_rq->push_cpu; - struct sched_domain *sd; - struct rq *target_rq; - - /* Is there any task to move? */ - if (busiest_rq->nr_running <= 1) - return; - - target_rq = cpu_rq(target_cpu); - - /* - * This condition is "impossible", if it occurs - * we need to fix it. Originally reported by - * Bjorn Helgaas on a 128-cpu setup. - */ - BUG_ON(busiest_rq == target_rq); - - /* move a task from busiest_rq to target_rq */ - double_lock_balance(busiest_rq, target_rq); - update_rq_clock(busiest_rq); - update_rq_clock(target_rq); - - /* Search for an sd spanning us and the target CPU. */ - for_each_domain(target_cpu, sd) { - if ((sd->flags & SD_LOAD_BALANCE) && - cpumask_test_cpu(busiest_cpu, sched_domain_span(sd))) - break; - } - - if (likely(sd)) { - schedstat_inc(sd, alb_count); - - if (move_one_task(target_rq, target_cpu, busiest_rq, - sd, CPU_IDLE)) - schedstat_inc(sd, alb_pushed); - else - schedstat_inc(sd, alb_failed); - } - double_unlock_balance(busiest_rq, target_rq); -} - -#ifdef CONFIG_NO_HZ -static struct { - atomic_t load_balancer; - cpumask_var_t cpu_mask; -} nohz ____cacheline_aligned = { - .load_balancer = ATOMIC_INIT(-1), -}; - -/* - * This routine will try to nominate the ilb (idle load balancing) - * owner among the cpus whose ticks are stopped. ilb owner will do the idle - * load balancing on behalf of all those cpus. If all the cpus in the system - * go into this tickless mode, then there will be no ilb owner (as there is - * no need for one) and all the cpus will sleep till the next wakeup event - * arrives... - * - * For the ilb owner, tick is not stopped. And this tick will be used - * for idle load balancing. ilb owner will still be part of - * nohz.cpu_mask.. - * - * While stopping the tick, this cpu will become the ilb owner if there - * is no other owner. And will be the owner till that cpu becomes busy - * or if all cpus in the system stop their ticks at which point - * there is no need for ilb owner. - * - * When the ilb owner becomes busy, it nominates another owner, during the - * next busy scheduler_tick() - */ -int select_nohz_load_balancer(int stop_tick) -{ - int cpu = smp_processor_id(); - - if (stop_tick) { - cpu_rq(cpu)->in_nohz_recently = 1; - - if (!cpu_active(cpu)) { - if (atomic_read(&nohz.load_balancer) != cpu) - return 0; - - /* - * If we are going offline and still the leader, - * give up! - */ - if (atomic_cmpxchg(&nohz.load_balancer, cpu, -1) != cpu) - BUG(); - - return 0; - } - - cpumask_set_cpu(cpu, nohz.cpu_mask); - - /* time for ilb owner also to sleep */ - if (cpumask_weight(nohz.cpu_mask) == num_online_cpus()) { - if (atomic_read(&nohz.load_balancer) == cpu) - atomic_set(&nohz.load_balancer, -1); - return 0; - } - - if (atomic_read(&nohz.load_balancer) == -1) { - /* make me the ilb owner */ - if (atomic_cmpxchg(&nohz.load_balancer, -1, cpu) == -1) - return 1; - } else if (atomic_read(&nohz.load_balancer) == cpu) - return 1; - } else { - if (!cpumask_test_cpu(cpu, nohz.cpu_mask)) - return 0; - - cpumask_clear_cpu(cpu, nohz.cpu_mask); - - if (atomic_read(&nohz.load_balancer) == cpu) - if (atomic_cmpxchg(&nohz.load_balancer, cpu, -1) != cpu) - BUG(); - } - return 0; -} -#endif - -static DEFINE_SPINLOCK(balancing); - -/* - * It checks each scheduling domain to see if it is due to be balanced, - * and initiates a balancing operation if so. - * - * Balancing parameters are set up in arch_init_sched_domains. - */ -static void rebalance_domains(int cpu, enum cpu_idle_type idle) -{ - int balance = 1; - struct rq *rq = cpu_rq(cpu); - unsigned long interval; - struct sched_domain *sd; - /* Earliest time when we have to do rebalance again */ - unsigned long next_balance = jiffies + 60*HZ; - int update_next_balance = 0; - int need_serialize; - - for_each_domain(cpu, sd) { - if (!(sd->flags & SD_LOAD_BALANCE)) - continue; - - interval = sd->balance_interval; - if (idle != CPU_IDLE) - interval *= sd->busy_factor; - - /* scale ms to jiffies */ - interval = msecs_to_jiffies(interval); - if (unlikely(!interval)) - interval = 1; - if (interval > HZ*NR_CPUS/10) - interval = HZ*NR_CPUS/10; - - need_serialize = sd->flags & SD_SERIALIZE; - - if (need_serialize) { - if (!spin_trylock(&balancing)) - goto out; - } - - if (time_after_eq(jiffies, sd->last_balance + interval)) { - if (load_balance(cpu, rq, sd, idle, &balance)) { - /* - * We've pulled tasks over so either we're no - * longer idle, or one of our SMT siblings is - * not idle. - */ - idle = CPU_NOT_IDLE; - } - sd->last_balance = jiffies; - } - if (need_serialize) - spin_unlock(&balancing); -out: - if (time_after(next_balance, sd->last_balance + interval)) { - next_balance = sd->last_balance + interval; - update_next_balance = 1; - } - - /* - * Stop the load balance at this level. There is another - * CPU in our sched group which is doing load balancing more - * actively. - */ - if (!balance) - break; - } - - /* - * next_balance will be updated only when there is a need. - * When the cpu is attached to null domain for ex, it will not be - * updated. - */ - if (likely(update_next_balance)) - rq->next_balance = next_balance; -} - -/* - * run_rebalance_domains is triggered when needed from the scheduler tick. - * In CONFIG_NO_HZ case, the idle load balance owner will do the - * rebalancing for all the cpus for whom scheduler ticks are stopped. - */ -static void run_rebalance_domains(struct softirq_action *h) -{ - int this_cpu = smp_processor_id(); - struct rq *this_rq = cpu_rq(this_cpu); - enum cpu_idle_type idle = this_rq->idle_at_tick ? - CPU_IDLE : CPU_NOT_IDLE; - - rebalance_domains(this_cpu, idle); - -#ifdef CONFIG_NO_HZ - /* - * If this cpu is the owner for idle load balancing, then do the - * balancing on behalf of the other idle cpus whose ticks are - * stopped. - */ - if (this_rq->idle_at_tick && - atomic_read(&nohz.load_balancer) == this_cpu) { - struct rq *rq; - int balance_cpu; - - for_each_cpu(balance_cpu, nohz.cpu_mask) { - if (balance_cpu == this_cpu) - continue; - - /* - * If this cpu gets work to do, stop the load balancing - * work being done for other cpus. Next load - * balancing owner will pick it up. - */ - if (need_resched()) - break; - - rebalance_domains(balance_cpu, CPU_IDLE); - - rq = cpu_rq(balance_cpu); - if (time_after(this_rq->next_balance, rq->next_balance)) - this_rq->next_balance = rq->next_balance; - } - } -#endif -} - -static inline int on_null_domain(int cpu) -{ - return !rcu_dereference(cpu_rq(cpu)->sd); -} - -/* - * Trigger the SCHED_SOFTIRQ if it is time to do periodic load balancing. - * - * In case of CONFIG_NO_HZ, this is the place where we nominate a new - * idle load balancing owner or decide to stop the periodic load balancing, - * if the whole system is idle. - */ -static inline void trigger_load_balance(struct rq *rq, int cpu) -{ -#ifdef CONFIG_NO_HZ - /* - * If we were in the nohz mode recently and busy at the current - * scheduler tick, then check if we need to nominate new idle - * load balancer. - */ - if (rq->in_nohz_recently && !rq->idle_at_tick) { - rq->in_nohz_recently = 0; - - if (atomic_read(&nohz.load_balancer) == cpu) { - cpumask_clear_cpu(cpu, nohz.cpu_mask); - atomic_set(&nohz.load_balancer, -1); - } - - if (atomic_read(&nohz.load_balancer) == -1) { - /* - * simple selection for now: Nominate the - * first cpu in the nohz list to be the next - * ilb owner. - * - * TBD: Traverse the sched domains and nominate - * the nearest cpu in the nohz.cpu_mask. - */ - int ilb = cpumask_first(nohz.cpu_mask); - - if (ilb < nr_cpu_ids) - resched_cpu(ilb); - } - } - - /* - * If this cpu is idle and doing idle load balancing for all the - * cpus with ticks stopped, is it time for that to stop? - */ - if (rq->idle_at_tick && atomic_read(&nohz.load_balancer) == cpu && - cpumask_weight(nohz.cpu_mask) == num_online_cpus()) { - resched_cpu(cpu); - return; - } - - /* - * If this cpu is idle and the idle load balancing is done by - * someone else, then no need raise the SCHED_SOFTIRQ - */ - if (rq->idle_at_tick && atomic_read(&nohz.load_balancer) != cpu && - cpumask_test_cpu(cpu, nohz.cpu_mask)) - return; -#endif - /* Don't need to rebalance while attached to NULL domain */ - if (time_after_eq(jiffies, rq->next_balance) && - likely(!on_null_domain(cpu))) - raise_softirq(SCHED_SOFTIRQ); -} - -#else /* CONFIG_SMP */ - -/* - * on UP we do not need to balance between CPUs: - */ -static inline void idle_balance(int cpu, struct rq *rq) -{ -} - -#endif - -DEFINE_PER_CPU(struct kernel_stat, kstat); - -EXPORT_PER_CPU_SYMBOL(kstat); - -/* - * Return any ns on the sched_clock that have not yet been accounted in - * @p in case that task is currently running. - * - * Called with task_rq_lock() held on @rq. - */ -static u64 do_task_delta_exec(struct task_struct *p, struct rq *rq) -{ - u64 ns = 0; - - if (task_current(rq, p)) { - update_rq_clock(rq); - ns = rq->clock - p->se.exec_start; - if ((s64)ns < 0) - ns = 0; - } - - return ns; -} - -unsigned long long task_delta_exec(struct task_struct *p) -{ - unsigned long flags; - struct rq *rq; - u64 ns = 0; - - rq = task_rq_lock(p, &flags); - ns = do_task_delta_exec(p, rq); - task_rq_unlock(rq, &flags); - - return ns; -} - -/* - * Return accounted runtime for the task. - * In case the task is currently running, return the runtime plus current's - * pending runtime that have not been accounted yet. - */ -unsigned long long task_sched_runtime(struct task_struct *p) -{ - unsigned long flags; - struct rq *rq; - u64 ns = 0; - - rq = task_rq_lock(p, &flags); - ns = p->se.sum_exec_runtime + do_task_delta_exec(p, rq); - task_rq_unlock(rq, &flags); - - return ns; -} - -/* - * Return sum_exec_runtime for the thread group. - * In case the task is currently running, return the sum plus current's - * pending runtime that have not been accounted yet. - * - * Note that the thread group might have other running tasks as well, - * so the return value not includes other pending runtime that other - * running tasks might have. - */ -unsigned long long thread_group_sched_runtime(struct task_struct *p) -{ - struct task_cputime totals; - unsigned long flags; - struct rq *rq; - u64 ns; - - rq = task_rq_lock(p, &flags); - thread_group_cputime(p, &totals); - ns = totals.sum_exec_runtime + do_task_delta_exec(p, rq); - task_rq_unlock(rq, &flags); - - return ns; -} - -/* - * Account user cpu time to a process. - * @p: the process that the cpu time gets accounted to - * @cputime: the cpu time spent in user space since the last update - * @cputime_scaled: cputime scaled by cpu frequency - */ -void account_user_time(struct task_struct *p, cputime_t cputime, - cputime_t cputime_scaled) -{ - struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat; - cputime64_t tmp; - - /* Add user time to process. */ - p->utime = cputime_add(p->utime, cputime); - p->utimescaled = cputime_add(p->utimescaled, cputime_scaled); - account_group_user_time(p, cputime); - - /* Add user time to cpustat. */ - tmp = cputime_to_cputime64(cputime); - if (TASK_NICE(p) > 0) - cpustat->nice = cputime64_add(cpustat->nice, tmp); - else - cpustat->user = cputime64_add(cpustat->user, tmp); - - cpuacct_update_stats(p, CPUACCT_STAT_USER, cputime); - /* Account for user time used */ - acct_update_integrals(p); -} - -/* - * Account guest cpu time to a process. - * @p: the process that the cpu time gets accounted to - * @cputime: the cpu time spent in virtual machine since the last update - * @cputime_scaled: cputime scaled by cpu frequency - */ -static void account_guest_time(struct task_struct *p, cputime_t cputime, - cputime_t cputime_scaled) -{ - cputime64_t tmp; - struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat; - - tmp = cputime_to_cputime64(cputime); - - /* Add guest time to process. */ - p->utime = cputime_add(p->utime, cputime); - p->utimescaled = cputime_add(p->utimescaled, cputime_scaled); - account_group_user_time(p, cputime); - p->gtime = cputime_add(p->gtime, cputime); - - /* Add guest time to cpustat. */ - cpustat->user = cputime64_add(cpustat->user, tmp); - cpustat->guest = cputime64_add(cpustat->guest, tmp); -} - -/* - * Account system cpu time to a process. - * @p: the process that the cpu time gets accounted to - * @hardirq_offset: the offset to subtract from hardirq_count() - * @cputime: the cpu time spent in kernel space since the last update - * @cputime_scaled: cputime scaled by cpu frequency - */ -void account_system_time(struct task_struct *p, int hardirq_offset, - cputime_t cputime, cputime_t cputime_scaled) -{ - struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat; - cputime64_t tmp; - - if ((p->flags & PF_VCPU) && (irq_count() - hardirq_offset == 0)) { - account_guest_time(p, cputime, cputime_scaled); - return; - } - - /* Add system time to process. */ - p->stime = cputime_add(p->stime, cputime); - p->stimescaled = cputime_add(p->stimescaled, cputime_scaled); - account_group_system_time(p, cputime); - - /* Add system time to cpustat. */ - tmp = cputime_to_cputime64(cputime); - if (hardirq_count() - hardirq_offset) - cpustat->irq = cputime64_add(cpustat->irq, tmp); - else if (softirq_count()) - cpustat->softirq = cputime64_add(cpustat->softirq, tmp); - else - cpustat->system = cputime64_add(cpustat->system, tmp); - - cpuacct_update_stats(p, CPUACCT_STAT_SYSTEM, cputime); - - /* Account for system time used */ - acct_update_integrals(p); -} - -/* - * Account for involuntary wait time. - * @steal: the cpu time spent in involuntary wait - */ -void account_steal_time(cputime_t cputime) -{ - struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat; - cputime64_t cputime64 = cputime_to_cputime64(cputime); - - cpustat->steal = cputime64_add(cpustat->steal, cputime64); -} - -/* - * Account for idle time. - * @cputime: the cpu time spent in idle wait - */ -void account_idle_time(cputime_t cputime) -{ - struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat; - cputime64_t cputime64 = cputime_to_cputime64(cputime); - struct rq *rq = this_rq(); - - if (atomic_read(&rq->nr_iowait) > 0) - cpustat->iowait = cputime64_add(cpustat->iowait, cputime64); - else - cpustat->idle = cputime64_add(cpustat->idle, cputime64); -} - -#ifndef CONFIG_VIRT_CPU_ACCOUNTING - -/* - * Account a single tick of cpu time. - * @p: the process that the cpu time gets accounted to - * @user_tick: indicates if the tick is a user or a system tick - */ -void account_process_tick(struct task_struct *p, int user_tick) -{ - cputime_t one_jiffy = jiffies_to_cputime(1); - cputime_t one_jiffy_scaled = cputime_to_scaled(one_jiffy); - struct rq *rq = this_rq(); - - if (user_tick) - account_user_time(p, one_jiffy, one_jiffy_scaled); - else if ((p != rq->idle) || (irq_count() != HARDIRQ_OFFSET)) - account_system_time(p, HARDIRQ_OFFSET, one_jiffy, - one_jiffy_scaled); - else - account_idle_time(one_jiffy); -} - -/* - * Account multiple ticks of steal time. - * @p: the process from which the cpu time has been stolen - * @ticks: number of stolen ticks - */ -void account_steal_ticks(unsigned long ticks) -{ - account_steal_time(jiffies_to_cputime(ticks)); -} - -/* - * Account multiple ticks of idle time. - * @ticks: number of stolen ticks - */ -void account_idle_ticks(unsigned long ticks) -{ - account_idle_time(jiffies_to_cputime(ticks)); -} - -#endif - -/* - * Use precise platform statistics if available: - */ -#ifdef CONFIG_VIRT_CPU_ACCOUNTING -cputime_t task_utime(struct task_struct *p) -{ - return p->utime; -} - -cputime_t task_stime(struct task_struct *p) -{ - return p->stime; -} -#else -cputime_t task_utime(struct task_struct *p) -{ - clock_t utime = cputime_to_clock_t(p->utime), - total = utime + cputime_to_clock_t(p->stime); - u64 temp; - - /* - * Use CFS's precise accounting: - */ - temp = (u64)nsec_to_clock_t(p->se.sum_exec_runtime); - - if (total) { - temp *= utime; - do_div(temp, total); - } - utime = (clock_t)temp; - - p->prev_utime = max(p->prev_utime, clock_t_to_cputime(utime)); - return p->prev_utime; -} - -cputime_t task_stime(struct task_struct *p) -{ - clock_t stime; - - /* - * Use CFS's precise accounting. (we subtract utime from - * the total, to make sure the total observed by userspace - * grows monotonically - apps rely on that): - */ - stime = nsec_to_clock_t(p->se.sum_exec_runtime) - - cputime_to_clock_t(task_utime(p)); - - if (stime >= 0) - p->prev_stime = max(p->prev_stime, clock_t_to_cputime(stime)); - - return p->prev_stime; -} -#endif - -inline cputime_t task_gtime(struct task_struct *p) -{ - return p->gtime; -} - -/* - * This function gets called by the timer code, with HZ frequency. - * We call it with interrupts disabled. - * - * It also gets called by the fork code, when changing the parent's - * timeslices. - */ -void scheduler_tick(void) -{ - int cpu = smp_processor_id(); - struct rq *rq = cpu_rq(cpu); - struct task_struct *curr = rq->curr; - - sched_clock_tick(); - - spin_lock(&rq->lock); - update_rq_clock(rq); - update_cpu_load(rq); - curr->sched_class->task_tick(rq, curr, 0); - spin_unlock(&rq->lock); - -#ifdef CONFIG_SMP - rq->idle_at_tick = idle_cpu(cpu); - trigger_load_balance(rq, cpu); -#endif -} - -notrace unsigned long get_parent_ip(unsigned long addr) -{ - if (in_lock_functions(addr)) { - addr = CALLER_ADDR2; - if (in_lock_functions(addr)) - addr = CALLER_ADDR3; - } - return addr; -} - -#if defined(CONFIG_PREEMPT) && (defined(CONFIG_DEBUG_PREEMPT) || \ - defined(CONFIG_PREEMPT_TRACER)) - -void __kprobes add_preempt_count(int val) -{ -#ifdef CONFIG_DEBUG_PREEMPT - /* - * Underflow? - */ - if (DEBUG_LOCKS_WARN_ON((preempt_count() < 0))) - return; -#endif - preempt_count() += val; -#ifdef CONFIG_DEBUG_PREEMPT - /* - * Spinlock count overflowing soon? - */ - DEBUG_LOCKS_WARN_ON((preempt_count() & PREEMPT_MASK) >= - PREEMPT_MASK - 10); -#endif - if (preempt_count() == val) - trace_preempt_off(CALLER_ADDR0, get_parent_ip(CALLER_ADDR1)); -} -EXPORT_SYMBOL(add_preempt_count); - -void __kprobes sub_preempt_count(int val) -{ -#ifdef CONFIG_DEBUG_PREEMPT - /* - * Underflow? - */ - if (DEBUG_LOCKS_WARN_ON(val > preempt_count())) - return; - /* - * Is the spinlock portion underflowing? - */ - if (DEBUG_LOCKS_WARN_ON((val < PREEMPT_MASK) && - !(preempt_count() & PREEMPT_MASK))) - return; -#endif - - if (preempt_count() == val) - trace_preempt_on(CALLER_ADDR0, get_parent_ip(CALLER_ADDR1)); - preempt_count() -= val; -} -EXPORT_SYMBOL(sub_preempt_count); - -#endif - -/* - * Print scheduling while atomic bug: - */ -static noinline void __schedule_bug(struct task_struct *prev) -{ - struct pt_regs *regs = get_irq_regs(); - - printk(KERN_ERR "BUG: scheduling while atomic: %s/%d/0x%08x\n", - prev->comm, prev->pid, preempt_count()); - - debug_show_held_locks(prev); - print_modules(); - if (irqs_disabled()) - print_irqtrace_events(prev); - - if (regs) - show_regs(regs); - else - dump_stack(); -} - -/* - * Various schedule()-time debugging checks and statistics: - */ -static inline void schedule_debug(struct task_struct *prev) -{ - /* - * Test if we are atomic. Since do_exit() needs to call into - * schedule() atomically, we ignore that path for now. - * Otherwise, whine if we are scheduling when we should not be. - */ - if (unlikely(in_atomic_preempt_off() && !prev->exit_state)) - __schedule_bug(prev); - - profile_hit(SCHED_PROFILING, __builtin_return_address(0)); - - schedstat_inc(this_rq(), sched_count); -#ifdef CONFIG_SCHEDSTATS - if (unlikely(prev->lock_depth >= 0)) { - schedstat_inc(this_rq(), bkl_count); - schedstat_inc(prev, sched_info.bkl_count); - } -#endif -} - -static void put_prev_task(struct rq *rq, struct task_struct *prev) -{ - if (prev->state == TASK_RUNNING) { - u64 runtime = prev->se.sum_exec_runtime; - - runtime -= prev->se.prev_sum_exec_runtime; - runtime = min_t(u64, runtime, 2*sysctl_sched_migration_cost); - - /* - * In order to avoid avg_overlap growing stale when we are - * indeed overlapping and hence not getting put to sleep, grow - * the avg_overlap on preemption. - * - * We use the average preemption runtime because that - * correlates to the amount of cache footprint a task can - * build up. - */ - update_avg(&prev->se.avg_overlap, runtime); - } - prev->sched_class->put_prev_task(rq, prev); -} - -/* - * Pick up the highest-prio task: - */ -static inline struct task_struct * -pick_next_task(struct rq *rq) -{ - const struct sched_class *class; - struct task_struct *p; - - /* - * Optimization: we know that if all tasks are in - * the fair class we can call that function directly: - */ - if (likely(rq->nr_running == rq->cfs.nr_running)) { - p = fair_sched_class.pick_next_task(rq); - if (likely(p)) - return p; - } - - class = sched_class_highest; - for ( ; ; ) { - p = class->pick_next_task(rq); - if (p) - return p; - /* - * Will never be NULL as the idle class always - * returns a non-NULL p: - */ - class = class->next; - } -} - -/* - * schedule() is the main scheduler function. - */ -asmlinkage void __sched __schedule(void) -{ - struct task_struct *prev, *next; - unsigned long *switch_count; - struct rq *rq; - int cpu; - - cpu = smp_processor_id(); - rq = cpu_rq(cpu); - rcu_qsctr_inc(cpu); - prev = rq->curr; - switch_count = &prev->nivcsw; - - release_kernel_lock(prev); -need_resched_nonpreemptible: - - schedule_debug(prev); - - if (sched_feat(HRTICK)) - hrtick_clear(rq); - - spin_lock_irq(&rq->lock); - update_rq_clock(rq); - clear_tsk_need_resched(prev); - - if (prev->state && !(preempt_count() & PREEMPT_ACTIVE)) { - if (unlikely(signal_pending_state(prev->state, prev))) - prev->state = TASK_RUNNING; - else - deactivate_task(rq, prev, 1); - switch_count = &prev->nvcsw; - } - -#ifdef CONFIG_SMP - if (prev->sched_class->pre_schedule) - prev->sched_class->pre_schedule(rq, prev); -#endif - - if (unlikely(!rq->nr_running)) - idle_balance(cpu, rq); - - put_prev_task(rq, prev); - next = pick_next_task(rq); - - if (likely(prev != next)) { - sched_info_switch(prev, next); - - rq->nr_switches++; - rq->curr = next; - ++*switch_count; - - context_switch(rq, prev, next); /* unlocks the rq */ - /* - * the context switch might have flipped the stack from under - * us, hence refresh the local variables. - */ - cpu = smp_processor_id(); - rq = cpu_rq(cpu); - } else - spin_unlock_irq(&rq->lock); - - if (unlikely(reacquire_kernel_lock(current) < 0)) - goto need_resched_nonpreemptible; -} - -asmlinkage void __sched schedule(void) -{ -need_resched: - preempt_disable(); - __schedule(); - preempt_enable_no_resched(); - if (unlikely(test_thread_flag(TIF_NEED_RESCHED))) - goto need_resched; -} -EXPORT_SYMBOL(schedule); - -#ifdef CONFIG_SMP -/* - * Look out! "owner" is an entirely speculative pointer - * access and not reliable. - */ -int mutex_spin_on_owner(struct mutex *lock, struct thread_info *owner) -{ - unsigned int cpu; - struct rq *rq; - - if (!sched_feat(OWNER_SPIN)) - return 0; - -#ifdef CONFIG_DEBUG_PAGEALLOC - /* - * Need to access the cpu field knowing that - * DEBUG_PAGEALLOC could have unmapped it if - * the mutex owner just released it and exited. - */ - if (probe_kernel_address(&owner->cpu, cpu)) - goto out; -#else - cpu = owner->cpu; -#endif - - /* - * Even if the access succeeded (likely case), - * the cpu field may no longer be valid. - */ - if (cpu >= nr_cpumask_bits) - goto out; - - /* - * We need to validate that we can do a - * get_cpu() and that we have the percpu area. - */ - if (!cpu_online(cpu)) - goto out; - - rq = cpu_rq(cpu); - - for (;;) { - /* - * Owner changed, break to re-assess state. - */ - if (lock->owner != owner) - break; - - /* - * Is that owner really running on that cpu? - */ - if (task_thread_info(rq->curr) != owner || need_resched()) - return 0; - - cpu_relax(); - } -out: - return 1; -} -#endif - -#ifdef CONFIG_PREEMPT -/* - * this is the entry point to schedule() from in-kernel preemption - * off of preempt_enable. Kernel preemptions off return from interrupt - * occur there and call schedule directly. - */ -asmlinkage void __sched preempt_schedule(void) -{ - struct thread_info *ti = current_thread_info(); - - /* - * If there is a non-zero preempt_count or interrupts are disabled, - * we do not want to preempt the current task. Just return.. - */ - if (likely(ti->preempt_count || irqs_disabled())) - return; - - do { - add_preempt_count(PREEMPT_ACTIVE); - schedule(); - sub_preempt_count(PREEMPT_ACTIVE); - - /* - * Check again in case we missed a preemption opportunity - * between schedule and now. - */ - barrier(); - } while (need_resched()); -} -EXPORT_SYMBOL(preempt_schedule); - -/* - * this is the entry point to schedule() from kernel preemption - * off of irq context. - * Note, that this is called and return with irqs disabled. This will - * protect us against recursive calling from irq. - */ -asmlinkage void __sched preempt_schedule_irq(void) -{ - struct thread_info *ti = current_thread_info(); - - /* Catch callers which need to be fixed */ - BUG_ON(ti->preempt_count || !irqs_disabled()); - - do { - add_preempt_count(PREEMPT_ACTIVE); - local_irq_enable(); - schedule(); - local_irq_disable(); - sub_preempt_count(PREEMPT_ACTIVE); - - /* - * Check again in case we missed a preemption opportunity - * between schedule and now. - */ - barrier(); - } while (need_resched()); -} - -#endif /* CONFIG_PREEMPT */ - -int default_wake_function(wait_queue_t *curr, unsigned mode, int sync, - void *key) -{ - return try_to_wake_up(curr->private, mode, sync); -} -EXPORT_SYMBOL(default_wake_function); - -/* - * The core wakeup function. Non-exclusive wakeups (nr_exclusive == 0) just - * wake everything up. If it's an exclusive wakeup (nr_exclusive == small +ve - * number) then we wake all the non-exclusive tasks and one exclusive task. - * - * There are circumstances in which we can try to wake a task which has already - * started to run but is not in state TASK_RUNNING. try_to_wake_up() returns - * zero in this (rare) case, and we handle it by continuing to scan the queue. - */ -void __wake_up_common(wait_queue_head_t *q, unsigned int mode, - int nr_exclusive, int sync, void *key) -{ - wait_queue_t *curr, *next; - - list_for_each_entry_safe(curr, next, &q->task_list, task_list) { - unsigned flags = curr->flags; - - if (curr->func(curr, mode, sync, key) && - (flags & WQ_FLAG_EXCLUSIVE) && !--nr_exclusive) - break; - } -} - -/** - * __wake_up - wake up threads blocked on a waitqueue. - * @q: the waitqueue - * @mode: which threads - * @nr_exclusive: how many wake-one or wake-many threads to wake up - * @key: is directly passed to the wakeup function - */ -void __wake_up(wait_queue_head_t *q, unsigned int mode, - int nr_exclusive, void *key) -{ - unsigned long flags; - - spin_lock_irqsave(&q->lock, flags); - __wake_up_common(q, mode, nr_exclusive, 0, key); - spin_unlock_irqrestore(&q->lock, flags); -} -EXPORT_SYMBOL(__wake_up); - -/* - * Same as __wake_up but called with the spinlock in wait_queue_head_t held. - */ -void __wake_up_locked(wait_queue_head_t *q, unsigned int mode) -{ - __wake_up_common(q, mode, 1, 0, NULL); -} - -void __wake_up_locked_key(wait_queue_head_t *q, unsigned int mode, void *key) -{ - __wake_up_common(q, mode, 1, 0, key); -} - -/** - * __wake_up_sync_key - wake up threads blocked on a waitqueue. - * @q: the waitqueue - * @mode: which threads - * @nr_exclusive: how many wake-one or wake-many threads to wake up - * @key: opaque value to be passed to wakeup targets - * - * The sync wakeup differs that the waker knows that it will schedule - * away soon, so while the target thread will be woken up, it will not - * be migrated to another CPU - ie. the two threads are 'synchronized' - * with each other. This can prevent needless bouncing between CPUs. - * - * On UP it can prevent extra preemption. - */ -void __wake_up_sync_key(wait_queue_head_t *q, unsigned int mode, - int nr_exclusive, void *key) -{ - unsigned long flags; - int sync = 1; - - if (unlikely(!q)) - return; - - if (unlikely(!nr_exclusive)) - sync = 0; - - spin_lock_irqsave(&q->lock, flags); - __wake_up_common(q, mode, nr_exclusive, sync, key); - spin_unlock_irqrestore(&q->lock, flags); -} -EXPORT_SYMBOL_GPL(__wake_up_sync_key); - -/* - * __wake_up_sync - see __wake_up_sync_key() - */ -void __wake_up_sync(wait_queue_head_t *q, unsigned int mode, int nr_exclusive) -{ - __wake_up_sync_key(q, mode, nr_exclusive, NULL); -} -EXPORT_SYMBOL_GPL(__wake_up_sync); /* For internal use only */ - -/** - * complete: - signals a single thread waiting on this completion - * @x: holds the state of this particular completion - * - * This will wake up a single thread waiting on this completion. Threads will be - * awakened in the same order in which they were queued. - * - * See also complete_all(), wait_for_completion() and related routines. - */ -void complete(struct completion *x) -{ - unsigned long flags; - - spin_lock_irqsave(&x->wait.lock, flags); - x->done++; - __wake_up_common(&x->wait, TASK_NORMAL, 1, 0, NULL); - spin_unlock_irqrestore(&x->wait.lock, flags); -} -EXPORT_SYMBOL(complete); - -/** - * complete_all: - signals all threads waiting on this completion - * @x: holds the state of this particular completion - * - * This will wake up all threads waiting on this particular completion event. - */ -void complete_all(struct completion *x) -{ - unsigned long flags; - - spin_lock_irqsave(&x->wait.lock, flags); - x->done += UINT_MAX/2; - __wake_up_common(&x->wait, TASK_NORMAL, 0, 0, NULL); - spin_unlock_irqrestore(&x->wait.lock, flags); -} -EXPORT_SYMBOL(complete_all); - -static inline long __sched -do_wait_for_common(struct completion *x, long timeout, int state) -{ - if (!x->done) { - DECLARE_WAITQUEUE(wait, current); - - wait.flags |= WQ_FLAG_EXCLUSIVE; - __add_wait_queue_tail(&x->wait, &wait); - do { - if (signal_pending_state(state, current)) { - timeout = -ERESTARTSYS; - break; - } - __set_current_state(state); - spin_unlock_irq(&x->wait.lock); - timeout = schedule_timeout(timeout); - spin_lock_irq(&x->wait.lock); - } while (!x->done && timeout); - __remove_wait_queue(&x->wait, &wait); - if (!x->done) - return timeout; - } - x->done--; - return timeout ?: 1; -} - -static long __sched -wait_for_common(struct completion *x, long timeout, int state) -{ - might_sleep(); - - spin_lock_irq(&x->wait.lock); - timeout = do_wait_for_common(x, timeout, state); - spin_unlock_irq(&x->wait.lock); - return timeout; -} - -/** - * wait_for_completion: - waits for completion of a task - * @x: holds the state of this particular completion - * - * This waits to be signaled for completion of a specific task. It is NOT - * interruptible and there is no timeout. - * - * See also similar routines (i.e. wait_for_completion_timeout()) with timeout - * and interrupt capability. Also see complete(). - */ -void __sched wait_for_completion(struct completion *x) -{ - wait_for_common(x, MAX_SCHEDULE_TIMEOUT, TASK_UNINTERRUPTIBLE); -} -EXPORT_SYMBOL(wait_for_completion); - -/** - * wait_for_completion_timeout: - waits for completion of a task (w/timeout) - * @x: holds the state of this particular completion - * @timeout: timeout value in jiffies - * - * This waits for either a completion of a specific task to be signaled or for a - * specified timeout to expire. The timeout is in jiffies. It is not - * interruptible. - */ -unsigned long __sched -wait_for_completion_timeout(struct completion *x, unsigned long timeout) -{ - return wait_for_common(x, timeout, TASK_UNINTERRUPTIBLE); -} -EXPORT_SYMBOL(wait_for_completion_timeout); - -/** - * wait_for_completion_interruptible: - waits for completion of a task (w/intr) - * @x: holds the state of this particular completion - * - * This waits for completion of a specific task to be signaled. It is - * interruptible. - */ -int __sched wait_for_completion_interruptible(struct completion *x) -{ - long t = wait_for_common(x, MAX_SCHEDULE_TIMEOUT, TASK_INTERRUPTIBLE); - if (t == -ERESTARTSYS) - return t; - return 0; -} -EXPORT_SYMBOL(wait_for_completion_interruptible); - -/** - * wait_for_completion_interruptible_timeout: - waits for completion (w/(to,intr)) - * @x: holds the state of this particular completion - * @timeout: timeout value in jiffies - * - * This waits for either a completion of a specific task to be signaled or for a - * specified timeout to expire. It is interruptible. The timeout is in jiffies. - */ -unsigned long __sched -wait_for_completion_interruptible_timeout(struct completion *x, - unsigned long timeout) -{ - return wait_for_common(x, timeout, TASK_INTERRUPTIBLE); -} -EXPORT_SYMBOL(wait_for_completion_interruptible_timeout); - -/** - * wait_for_completion_killable: - waits for completion of a task (killable) - * @x: holds the state of this particular completion - * - * This waits to be signaled for completion of a specific task. It can be - * interrupted by a kill signal. - */ -int __sched wait_for_completion_killable(struct completion *x) -{ - long t = wait_for_common(x, MAX_SCHEDULE_TIMEOUT, TASK_KILLABLE); - if (t == -ERESTARTSYS) - return t; - return 0; -} -EXPORT_SYMBOL(wait_for_completion_killable); - -/** - * try_wait_for_completion - try to decrement a completion without blocking - * @x: completion structure - * - * Returns: 0 if a decrement cannot be done without blocking - * 1 if a decrement succeeded. - * - * If a completion is being used as a counting completion, - * attempt to decrement the counter without blocking. This - * enables us to avoid waiting if the resource the completion - * is protecting is not available. - */ -bool try_wait_for_completion(struct completion *x) -{ - int ret = 1; - - spin_lock_irq(&x->wait.lock); - if (!x->done) - ret = 0; - else - x->done--; - spin_unlock_irq(&x->wait.lock); - return ret; -} -EXPORT_SYMBOL(try_wait_for_completion); - -/** - * completion_done - Test to see if a completion has any waiters - * @x: completion structure - * - * Returns: 0 if there are waiters (wait_for_completion() in progress) - * 1 if there are no waiters. - * - */ -bool completion_done(struct completion *x) -{ - int ret = 1; - - spin_lock_irq(&x->wait.lock); - if (!x->done) - ret = 0; - spin_unlock_irq(&x->wait.lock); - return ret; -} -EXPORT_SYMBOL(completion_done); - -static long __sched -sleep_on_common(wait_queue_head_t *q, int state, long timeout) -{ - unsigned long flags; - wait_queue_t wait; - - init_waitqueue_entry(&wait, current); - - __set_current_state(state); - - spin_lock_irqsave(&q->lock, flags); - __add_wait_queue(q, &wait); - spin_unlock(&q->lock); - timeout = schedule_timeout(timeout); - spin_lock_irq(&q->lock); - __remove_wait_queue(q, &wait); - spin_unlock_irqrestore(&q->lock, flags); - - return timeout; -} - -void __sched interruptible_sleep_on(wait_queue_head_t *q) -{ - sleep_on_common(q, TASK_INTERRUPTIBLE, MAX_SCHEDULE_TIMEOUT); -} -EXPORT_SYMBOL(interruptible_sleep_on); - -long __sched -interruptible_sleep_on_timeout(wait_queue_head_t *q, long timeout) -{ - return sleep_on_common(q, TASK_INTERRUPTIBLE, timeout); -} -EXPORT_SYMBOL(interruptible_sleep_on_timeout); - -void __sched sleep_on(wait_queue_head_t *q) -{ - sleep_on_common(q, TASK_UNINTERRUPTIBLE, MAX_SCHEDULE_TIMEOUT); -} -EXPORT_SYMBOL(sleep_on); - -long __sched sleep_on_timeout(wait_queue_head_t *q, long timeout) -{ - return sleep_on_common(q, TASK_UNINTERRUPTIBLE, timeout); -} -EXPORT_SYMBOL(sleep_on_timeout); - -#ifdef CONFIG_RT_MUTEXES - -/* - * rt_mutex_setprio - set the current priority of a task - * @p: task - * @prio: prio value (kernel-internal form) - * - * This function changes the 'effective' priority of a task. It does - * not touch ->normal_prio like __setscheduler(). - * - * Used by the rt_mutex code to implement priority inheritance logic. - */ -void rt_mutex_setprio(struct task_struct *p, int prio) -{ - unsigned long flags; - int oldprio, on_rq, running; - struct rq *rq; - const struct sched_class *prev_class = p->sched_class; - - BUG_ON(prio < 0 || prio > MAX_PRIO); - - rq = task_rq_lock(p, &flags); - update_rq_clock(rq); - - oldprio = p->prio; - on_rq = p->se.on_rq; - running = task_current(rq, p); - if (on_rq) - dequeue_task(rq, p, 0); - if (running) - p->sched_class->put_prev_task(rq, p); - - if (rt_prio(prio)) - p->sched_class = &rt_sched_class; - else - p->sched_class = &fair_sched_class; - - p->prio = prio; - - if (running) - p->sched_class->set_curr_task(rq); - if (on_rq) { - enqueue_task(rq, p, 0); - - check_class_changed(rq, p, prev_class, oldprio, running); - } - task_rq_unlock(rq, &flags); -} - -#endif - -void set_user_nice(struct task_struct *p, long nice) -{ - int old_prio, delta, on_rq; - unsigned long flags; - struct rq *rq; - - if (TASK_NICE(p) == nice || nice < -20 || nice > 19) - return; - /* - * We have to be careful, if called from sys_setpriority(), - * the task might be in the middle of scheduling on another CPU. - */ - rq = task_rq_lock(p, &flags); - update_rq_clock(rq); - /* - * The RT priorities are set via sched_setscheduler(), but we still - * allow the 'normal' nice value to be set - but as expected - * it wont have any effect on scheduling until the task is - * SCHED_FIFO/SCHED_RR: - */ - if (task_has_rt_policy(p)) { - p->static_prio = NICE_TO_PRIO(nice); - goto out_unlock; - } - on_rq = p->se.on_rq; - if (on_rq) - dequeue_task(rq, p, 0); - - p->static_prio = NICE_TO_PRIO(nice); - set_load_weight(p); - old_prio = p->prio; - p->prio = effective_prio(p); - delta = p->prio - old_prio; - - if (on_rq) { - enqueue_task(rq, p, 0); - /* - * If the task increased its priority or is running and - * lowered its priority, then reschedule its CPU: - */ - if (delta < 0 || (delta > 0 && task_running(rq, p))) - resched_task(rq->curr); - } -out_unlock: - task_rq_unlock(rq, &flags); -} -EXPORT_SYMBOL(set_user_nice); - -/* - * can_nice - check if a task can reduce its nice value - * @p: task - * @nice: nice value - */ -int can_nice(const struct task_struct *p, const int nice) -{ - /* convert nice value [19,-20] to rlimit style value [1,40] */ - int nice_rlim = 20 - nice; - - return (nice_rlim <= p->signal->rlim[RLIMIT_NICE].rlim_cur || - capable(CAP_SYS_NICE)); -} - -#ifdef __ARCH_WANT_SYS_NICE - -/* - * sys_nice - change the priority of the current process. - * @increment: priority increment - * - * sys_setpriority is a more generic, but much slower function that - * does similar things. - */ -SYSCALL_DEFINE1(nice, int, increment) -{ - long nice, retval; - - /* - * Setpriority might change our priority at the same moment. - * We don't have to worry. Conceptually one call occurs first - * and we have a single winner. - */ - if (increment < -40) - increment = -40; - if (increment > 40) - increment = 40; - - nice = TASK_NICE(current) + increment; - if (nice < -20) - nice = -20; - if (nice > 19) - nice = 19; - - if (increment < 0 && !can_nice(current, nice)) - return -EPERM; - - retval = security_task_setnice(current, nice); - if (retval) - return retval; - - set_user_nice(current, nice); - return 0; -} - -#endif - -/** - * task_prio - return the priority value of a given task. - * @p: the task in question. - * - * This is the priority value as seen by users in /proc. - * RT tasks are offset by -200. Normal tasks are centered - * around 0, value goes from -16 to +15. - */ -int task_prio(const struct task_struct *p) -{ - return p->prio - MAX_RT_PRIO; -} - -/** - * task_nice - return the nice value of a given task. - * @p: the task in question. - */ -int task_nice(const struct task_struct *p) -{ - return TASK_NICE(p); -} -EXPORT_SYMBOL(task_nice); - -/** - * idle_cpu - is a given cpu idle currently? - * @cpu: the processor in question. - */ -int idle_cpu(int cpu) -{ - return cpu_curr(cpu) == cpu_rq(cpu)->idle; -} - -/** - * idle_task - return the idle task for a given cpu. - * @cpu: the processor in question. - */ -struct task_struct *idle_task(int cpu) -{ - return cpu_rq(cpu)->idle; -} - -/** - * find_process_by_pid - find a process with a matching PID value. - * @pid: the pid in question. - */ -static struct task_struct *find_process_by_pid(pid_t pid) -{ - return pid ? find_task_by_vpid(pid) : current; -} - -/* Actually do priority change: must hold rq lock. */ -static void -__setscheduler(struct rq *rq, struct task_struct *p, int policy, int prio) -{ - BUG_ON(p->se.on_rq); - - p->policy = policy; - switch (p->policy) { - case SCHED_NORMAL: - case SCHED_BATCH: - case SCHED_IDLE: - p->sched_class = &fair_sched_class; - break; - case SCHED_FIFO: - case SCHED_RR: - p->sched_class = &rt_sched_class; - break; - } - - p->rt_priority = prio; - p->normal_prio = normal_prio(p); - /* we are holding p->pi_lock already */ - p->prio = rt_mutex_getprio(p); - set_load_weight(p); -} - -/* - * check the target process has a UID that matches the current process's - */ -static bool check_same_owner(struct task_struct *p) -{ - const struct cred *cred = current_cred(), *pcred; - bool match; - - rcu_read_lock(); - pcred = __task_cred(p); - match = (cred->euid == pcred->euid || - cred->euid == pcred->uid); - rcu_read_unlock(); - return match; -} - -static int __sched_setscheduler(struct task_struct *p, int policy, - struct sched_param *param, bool user) -{ - int retval, oldprio, oldpolicy = -1, on_rq, running; - unsigned long flags; - const struct sched_class *prev_class = p->sched_class; - struct rq *rq; - - /* may grab non-irq protected spin_locks */ - BUG_ON(in_interrupt()); -recheck: - /* double check policy once rq lock held */ - if (policy < 0) - policy = oldpolicy = p->policy; - else if (policy != SCHED_FIFO && policy != SCHED_RR && - policy != SCHED_NORMAL && policy != SCHED_BATCH && - policy != SCHED_IDLE) - return -EINVAL; - /* - * Valid priorities for SCHED_FIFO and SCHED_RR are - * 1..MAX_USER_RT_PRIO-1, valid priority for SCHED_NORMAL, - * SCHED_BATCH and SCHED_IDLE is 0. - */ - if (param->sched_priority < 0 || - (p->mm && param->sched_priority > MAX_USER_RT_PRIO-1) || - (!p->mm && param->sched_priority > MAX_RT_PRIO-1)) - return -EINVAL; - if (rt_policy(policy) != (param->sched_priority != 0)) - return -EINVAL; - - /* - * Allow unprivileged RT tasks to decrease priority: - */ - if (user && !capable(CAP_SYS_NICE)) { - if (rt_policy(policy)) { - unsigned long rlim_rtprio; - - if (!lock_task_sighand(p, &flags)) - return -ESRCH; - rlim_rtprio = p->signal->rlim[RLIMIT_RTPRIO].rlim_cur; - unlock_task_sighand(p, &flags); - - /* can't set/change the rt policy */ - if (policy != p->policy && !rlim_rtprio) - return -EPERM; - - /* can't increase priority */ - if (param->sched_priority > p->rt_priority && - param->sched_priority > rlim_rtprio) - return -EPERM; - } - /* - * Like positive nice levels, dont allow tasks to - * move out of SCHED_IDLE either: - */ - if (p->policy == SCHED_IDLE && policy != SCHED_IDLE) - return -EPERM; - - /* can't change other user's priorities */ - if (!check_same_owner(p)) - return -EPERM; - } - - if (user) { -#ifdef CONFIG_RT_GROUP_SCHED - /* - * Do not allow realtime tasks into groups that have no runtime - * assigned. - */ - if (rt_bandwidth_enabled() && rt_policy(policy) && - task_group(p)->rt_bandwidth.rt_runtime == 0) - return -EPERM; -#endif - - retval = security_task_setscheduler(p, policy, param); - if (retval) - return retval; - } - - /* - * make sure no PI-waiters arrive (or leave) while we are - * changing the priority of the task: - */ - spin_lock_irqsave(&p->pi_lock, flags); - /* - * To be able to change p->policy safely, the apropriate - * runqueue lock must be held. - */ - rq = __task_rq_lock(p); - /* recheck policy now with rq lock held */ - if (unlikely(oldpolicy != -1 && oldpolicy != p->policy)) { - policy = oldpolicy = -1; - __task_rq_unlock(rq); - spin_unlock_irqrestore(&p->pi_lock, flags); - goto recheck; - } - update_rq_clock(rq); - on_rq = p->se.on_rq; - running = task_current(rq, p); - if (on_rq) - deactivate_task(rq, p, 0); - if (running) - p->sched_class->put_prev_task(rq, p); - - oldprio = p->prio; - __setscheduler(rq, p, policy, param->sched_priority); - - if (running) - p->sched_class->set_curr_task(rq); - if (on_rq) { - activate_task(rq, p, 0); - - check_class_changed(rq, p, prev_class, oldprio, running); - } - __task_rq_unlock(rq); - spin_unlock_irqrestore(&p->pi_lock, flags); - - rt_mutex_adjust_pi(p); - - return 0; -} - -/** - * sched_setscheduler - change the scheduling policy and/or RT priority of a thread. - * @p: the task in question. - * @policy: new policy. - * @param: structure containing the new RT priority. - * - * NOTE that the task may be already dead. - */ -int sched_setscheduler(struct task_struct *p, int policy, - struct sched_param *param) -{ - return __sched_setscheduler(p, policy, param, true); -} -EXPORT_SYMBOL_GPL(sched_setscheduler); - -/** - * sched_setscheduler_nocheck - change the scheduling policy and/or RT priority of a thread from kernelspace. - * @p: the task in question. - * @policy: new policy. - * @param: structure containing the new RT priority. - * - * Just like sched_setscheduler, only don't bother checking if the - * current context has permission. For example, this is needed in - * stop_machine(): we create temporary high priority worker threads, - * but our caller might not have that capability. - */ -int sched_setscheduler_nocheck(struct task_struct *p, int policy, - struct sched_param *param) -{ - return __sched_setscheduler(p, policy, param, false); -} - -static int -do_sched_setscheduler(pid_t pid, int policy, struct sched_param __user *param) -{ - struct sched_param lparam; - struct task_struct *p; - int retval; - - if (!param || pid < 0) - return -EINVAL; - if (copy_from_user(&lparam, param, sizeof(struct sched_param))) - return -EFAULT; - - rcu_read_lock(); - retval = -ESRCH; - p = find_process_by_pid(pid); - if (p != NULL) - retval = sched_setscheduler(p, policy, &lparam); - rcu_read_unlock(); - - return retval; -} - -/** - * sys_sched_setscheduler - set/change the scheduler policy and RT priority - * @pid: the pid in question. - * @policy: new policy. - * @param: structure containing the new RT priority. - */ -SYSCALL_DEFINE3(sched_setscheduler, pid_t, pid, int, policy, - struct sched_param __user *, param) -{ - /* negative values for policy are not valid */ - if (policy < 0) - return -EINVAL; - - return do_sched_setscheduler(pid, policy, param); -} - -/** - * sys_sched_setparam - set/change the RT priority of a thread - * @pid: the pid in question. - * @param: structure containing the new RT priority. - */ -SYSCALL_DEFINE2(sched_setparam, pid_t, pid, struct sched_param __user *, param) -{ - return do_sched_setscheduler(pid, -1, param); -} - -/** - * sys_sched_getscheduler - get the policy (scheduling class) of a thread - * @pid: the pid in question. - */ -SYSCALL_DEFINE1(sched_getscheduler, pid_t, pid) -{ - struct task_struct *p; - int retval; - - if (pid < 0) - return -EINVAL; - - retval = -ESRCH; - read_lock(&tasklist_lock); - p = find_process_by_pid(pid); - if (p) { - retval = security_task_getscheduler(p); - if (!retval) - retval = p->policy; - } - read_unlock(&tasklist_lock); - return retval; -} - -/** - * sys_sched_getscheduler - get the RT priority of a thread - * @pid: the pid in question. - * @param: structure containing the RT priority. - */ -SYSCALL_DEFINE2(sched_getparam, pid_t, pid, struct sched_param __user *, param) -{ - struct sched_param lp; - struct task_struct *p; - int retval; - - if (!param || pid < 0) - return -EINVAL; - - read_lock(&tasklist_lock); - p = find_process_by_pid(pid); - retval = -ESRCH; - if (!p) - goto out_unlock; - - retval = security_task_getscheduler(p); - if (retval) - goto out_unlock; - - lp.sched_priority = p->rt_priority; - read_unlock(&tasklist_lock); - - /* - * This one might sleep, we cannot do it with a spinlock held ... - */ - retval = copy_to_user(param, &lp, sizeof(*param)) ? -EFAULT : 0; - - return retval; - -out_unlock: - read_unlock(&tasklist_lock); - return retval; -} - -long sched_setaffinity(pid_t pid, const struct cpumask *in_mask) -{ - cpumask_var_t cpus_allowed, new_mask; - struct task_struct *p; - int retval; - - get_online_cpus(); - read_lock(&tasklist_lock); - - p = find_process_by_pid(pid); - if (!p) { - read_unlock(&tasklist_lock); - put_online_cpus(); - return -ESRCH; - } - - /* - * It is not safe to call set_cpus_allowed with the - * tasklist_lock held. We will bump the task_struct's - * usage count and then drop tasklist_lock. - */ - get_task_struct(p); - read_unlock(&tasklist_lock); - - if (!alloc_cpumask_var(&cpus_allowed, GFP_KERNEL)) { - retval = -ENOMEM; - goto out_put_task; - } - if (!alloc_cpumask_var(&new_mask, GFP_KERNEL)) { - retval = -ENOMEM; - goto out_free_cpus_allowed; - } - retval = -EPERM; - if (!check_same_owner(p) && !capable(CAP_SYS_NICE)) - goto out_unlock; - - retval = security_task_setscheduler(p, 0, NULL); - if (retval) - goto out_unlock; - - cpuset_cpus_allowed(p, cpus_allowed); - cpumask_and(new_mask, in_mask, cpus_allowed); - again: - retval = set_cpus_allowed_ptr(p, new_mask); - - if (!retval) { - cpuset_cpus_allowed(p, cpus_allowed); - if (!cpumask_subset(new_mask, cpus_allowed)) { - /* - * We must have raced with a concurrent cpuset - * update. Just reset the cpus_allowed to the - * cpuset's cpus_allowed - */ - cpumask_copy(new_mask, cpus_allowed); - goto again; - } - } -out_unlock: - free_cpumask_var(new_mask); -out_free_cpus_allowed: - free_cpumask_var(cpus_allowed); -out_put_task: - put_task_struct(p); - put_online_cpus(); - return retval; -} - -static int get_user_cpu_mask(unsigned long __user *user_mask_ptr, unsigned len, - struct cpumask *new_mask) -{ - if (len < cpumask_size()) - cpumask_clear(new_mask); - else if (len > cpumask_size()) - len = cpumask_size(); - - return copy_from_user(new_mask, user_mask_ptr, len) ? -EFAULT : 0; -} - -/** - * sys_sched_setaffinity - set the cpu affinity of a process - * @pid: pid of the process - * @len: length in bytes of the bitmask pointed to by user_mask_ptr - * @user_mask_ptr: user-space pointer to the new cpu mask - */ -SYSCALL_DEFINE3(sched_setaffinity, pid_t, pid, unsigned int, len, - unsigned long __user *, user_mask_ptr) -{ - cpumask_var_t new_mask; - int retval; - - if (!alloc_cpumask_var(&new_mask, GFP_KERNEL)) - return -ENOMEM; - - retval = get_user_cpu_mask(user_mask_ptr, len, new_mask); - if (retval == 0) - retval = sched_setaffinity(pid, new_mask); - free_cpumask_var(new_mask); - return retval; -} - -long sched_getaffinity(pid_t pid, struct cpumask *mask) -{ - struct task_struct *p; - int retval; - - get_online_cpus(); - read_lock(&tasklist_lock); - - retval = -ESRCH; - p = find_process_by_pid(pid); - if (!p) - goto out_unlock; - - retval = security_task_getscheduler(p); - if (retval) - goto out_unlock; - - cpumask_and(mask, &p->cpus_allowed, cpu_online_mask); - -out_unlock: - read_unlock(&tasklist_lock); - put_online_cpus(); - - return retval; -} - -/** - * sys_sched_getaffinity - get the cpu affinity of a process - * @pid: pid of the process - * @len: length in bytes of the bitmask pointed to by user_mask_ptr - * @user_mask_ptr: user-space pointer to hold the current cpu mask - */ -SYSCALL_DEFINE3(sched_getaffinity, pid_t, pid, unsigned int, len, - unsigned long __user *, user_mask_ptr) -{ - int ret; - cpumask_var_t mask; - - if (len < cpumask_size()) - return -EINVAL; - - if (!alloc_cpumask_var(&mask, GFP_KERNEL)) - return -ENOMEM; - - ret = sched_getaffinity(pid, mask); - if (ret == 0) { - if (copy_to_user(user_mask_ptr, mask, cpumask_size())) - ret = -EFAULT; - else - ret = cpumask_size(); - } - free_cpumask_var(mask); - - return ret; -} - -/** - * sys_sched_yield - yield the current processor to other threads. - * - * This function yields the current CPU to other tasks. If there are no - * other threads running on this CPU then this function will return. - */ -SYSCALL_DEFINE0(sched_yield) -{ - struct rq *rq = this_rq_lock(); - - schedstat_inc(rq, yld_count); - current->sched_class->yield_task(rq); - - /* - * Since we are going to call schedule() anyway, there's - * no need to preempt or enable interrupts: - */ - __release(rq->lock); - spin_release(&rq->lock.dep_map, 1, _THIS_IP_); - _raw_spin_unlock(&rq->lock); - preempt_enable_no_resched(); - - schedule(); - - return 0; -} - -static void __cond_resched(void) -{ -#ifdef CONFIG_DEBUG_SPINLOCK_SLEEP - __might_sleep(__FILE__, __LINE__); -#endif - /* - * The BKS might be reacquired before we have dropped - * PREEMPT_ACTIVE, which could trigger a second - * cond_resched() call. - */ - do { - add_preempt_count(PREEMPT_ACTIVE); - schedule(); - sub_preempt_count(PREEMPT_ACTIVE); - } while (need_resched()); -} - -int __sched _cond_resched(void) -{ - if (need_resched() && !(preempt_count() & PREEMPT_ACTIVE) && - system_state == SYSTEM_RUNNING) { - __cond_resched(); - return 1; - } - return 0; -} -EXPORT_SYMBOL(_cond_resched); - -/* - * cond_resched_lock() - if a reschedule is pending, drop the given lock, - * call schedule, and on return reacquire the lock. - * - * This works OK both with and without CONFIG_PREEMPT. We do strange low-level - * operations here to prevent schedule() from being called twice (once via - * spin_unlock(), once by hand). - */ -int cond_resched_lock(spinlock_t *lock) -{ - int resched = need_resched() && system_state == SYSTEM_RUNNING; - int ret = 0; - - if (spin_needbreak(lock) || resched) { - spin_unlock(lock); - if (resched && need_resched()) - __cond_resched(); - else - cpu_relax(); - ret = 1; - spin_lock(lock); - } - return ret; -} -EXPORT_SYMBOL(cond_resched_lock); - -int __sched cond_resched_softirq(void) -{ - BUG_ON(!in_softirq()); - - if (need_resched() && system_state == SYSTEM_RUNNING) { - local_bh_enable(); - __cond_resched(); - local_bh_disable(); - return 1; - } - return 0; -} -EXPORT_SYMBOL(cond_resched_softirq); - -/** - * yield - yield the current processor to other threads. - * - * This is a shortcut for kernel-space yielding - it marks the - * thread runnable and calls sys_sched_yield(). - */ -void __sched yield(void) -{ - set_current_state(TASK_RUNNING); - sys_sched_yield(); -} -EXPORT_SYMBOL(yield); - -/* - * This task is about to go to sleep on IO. Increment rq->nr_iowait so - * that process accounting knows that this is a task in IO wait state. - * - * But don't do that if it is a deliberate, throttling IO wait (this task - * has set its backing_dev_info: the queue against which it should throttle) - */ -void __sched io_schedule(void) -{ - struct rq *rq = &__raw_get_cpu_var(runqueues); - - delayacct_blkio_start(); - atomic_inc(&rq->nr_iowait); - schedule(); - atomic_dec(&rq->nr_iowait); - delayacct_blkio_end(); -} -EXPORT_SYMBOL(io_schedule); - -long __sched io_schedule_timeout(long timeout) -{ - struct rq *rq = &__raw_get_cpu_var(runqueues); - long ret; - - delayacct_blkio_start(); - atomic_inc(&rq->nr_iowait); - ret = schedule_timeout(timeout); - atomic_dec(&rq->nr_iowait); - delayacct_blkio_end(); - return ret; -} - -/** - * sys_sched_get_priority_max - return maximum RT priority. - * @policy: scheduling class. - * - * this syscall returns the maximum rt_priority that can be used - * by a given scheduling class. - */ -SYSCALL_DEFINE1(sched_get_priority_max, int, policy) -{ - int ret = -EINVAL; - - switch (policy) { - case SCHED_FIFO: - case SCHED_RR: - ret = MAX_USER_RT_PRIO-1; - break; - case SCHED_NORMAL: - case SCHED_BATCH: - case SCHED_IDLE: - ret = 0; - break; - } - return ret; -} - -/** - * sys_sched_get_priority_min - return minimum RT priority. - * @policy: scheduling class. - * - * this syscall returns the minimum rt_priority that can be used - * by a given scheduling class. - */ -SYSCALL_DEFINE1(sched_get_priority_min, int, policy) -{ - int ret = -EINVAL; - - switch (policy) { - case SCHED_FIFO: - case SCHED_RR: - ret = 1; - break; - case SCHED_NORMAL: - case SCHED_BATCH: - case SCHED_IDLE: - ret = 0; - } - return ret; -} - -/** - * sys_sched_rr_get_interval - return the default timeslice of a process. - * @pid: pid of the process. - * @interval: userspace pointer to the timeslice value. - * - * this syscall writes the default timeslice value of a given process - * into the user-space timespec buffer. A value of '0' means infinity. - */ -SYSCALL_DEFINE2(sched_rr_get_interval, pid_t, pid, - struct timespec __user *, interval) -{ - struct task_struct *p; - unsigned int time_slice; - int retval; - struct timespec t; - - if (pid < 0) - return -EINVAL; - - retval = -ESRCH; - read_lock(&tasklist_lock); - p = find_process_by_pid(pid); - if (!p) - goto out_unlock; - - retval = security_task_getscheduler(p); - if (retval) - goto out_unlock; - - /* - * Time slice is 0 for SCHED_FIFO tasks and for SCHED_OTHER - * tasks that are on an otherwise idle runqueue: - */ - time_slice = 0; - if (p->policy == SCHED_RR) { - time_slice = DEF_TIMESLICE; - } else if (p->policy != SCHED_FIFO) { - struct sched_entity *se = &p->se; - unsigned long flags; - struct rq *rq; - - rq = task_rq_lock(p, &flags); - if (rq->cfs.load.weight) - time_slice = NS_TO_JIFFIES(sched_slice(&rq->cfs, se)); - task_rq_unlock(rq, &flags); - } - read_unlock(&tasklist_lock); - jiffies_to_timespec(time_slice, &t); - retval = copy_to_user(interval, &t, sizeof(t)) ? -EFAULT : 0; - return retval; - -out_unlock: - read_unlock(&tasklist_lock); - return retval; -} - -static const char stat_nam[] = TASK_STATE_TO_CHAR_STR; - -void sched_show_task(struct task_struct *p) -{ - unsigned long free = 0; - unsigned state; - - state = p->state ? __ffs(p->state) + 1 : 0; - printk(KERN_INFO "%-13.13s %c", p->comm, - state < sizeof(stat_nam) - 1 ? stat_nam[state] : '?'); -#if BITS_PER_LONG == 32 - if (state == TASK_RUNNING) - printk(KERN_CONT " running "); - else - printk(KERN_CONT " %08lx ", thread_saved_pc(p)); -#else - if (state == TASK_RUNNING) - printk(KERN_CONT " running task "); - else - printk(KERN_CONT " %016lx ", thread_saved_pc(p)); -#endif -#ifdef CONFIG_DEBUG_STACK_USAGE - free = stack_not_used(p); -#endif - printk(KERN_CONT "%5lu %5d %6d\n", free, - task_pid_nr(p), task_pid_nr(p->real_parent)); - - show_stack(p, NULL); -} - -void show_state_filter(unsigned long state_filter) -{ - struct task_struct *g, *p; - -#if BITS_PER_LONG == 32 - printk(KERN_INFO - " task PC stack pid father\n"); -#else - printk(KERN_INFO - " task PC stack pid father\n"); -#endif - read_lock(&tasklist_lock); - do_each_thread(g, p) { - /* - * reset the NMI-timeout, listing all files on a slow - * console might take alot of time: - */ - touch_nmi_watchdog(); - if (!state_filter || (p->state & state_filter)) - sched_show_task(p); - } while_each_thread(g, p); - - touch_all_softlockup_watchdogs(); - -#ifdef CONFIG_SCHED_DEBUG - sysrq_sched_debug_show(); -#endif - read_unlock(&tasklist_lock); - /* - * Only show locks if all tasks are dumped: - */ - if (state_filter == -1) - debug_show_all_locks(); -} - -void __cpuinit init_idle_bootup_task(struct task_struct *idle) -{ - idle->sched_class = &idle_sched_class; -} - -/** - * init_idle - set up an idle thread for a given CPU - * @idle: task in question - * @cpu: cpu the idle task belongs to - * - * NOTE: this function does not set the idle thread's NEED_RESCHED - * flag, to make booting more robust. - */ -void __cpuinit init_idle(struct task_struct *idle, int cpu) -{ - struct rq *rq = cpu_rq(cpu); - unsigned long flags; - - spin_lock_irqsave(&rq->lock, flags); - - __sched_fork(idle); - idle->se.exec_start = sched_clock(); - - idle->prio = idle->normal_prio = MAX_PRIO; - cpumask_copy(&idle->cpus_allowed, cpumask_of(cpu)); - __set_task_cpu(idle, cpu); - - rq->curr = rq->idle = idle; -#if defined(CONFIG_SMP) && defined(__ARCH_WANT_UNLOCKED_CTXSW) - idle->oncpu = 1; -#endif - spin_unlock_irqrestore(&rq->lock, flags); - - /* Set the preempt count _outside_ the spinlocks! */ -#if defined(CONFIG_PREEMPT) - task_thread_info(idle)->preempt_count = (idle->lock_depth >= 0); -#else - task_thread_info(idle)->preempt_count = 0; -#endif - /* - * The idle tasks have their own, simple scheduling class: - */ - idle->sched_class = &idle_sched_class; - ftrace_graph_init_task(idle); -} - -/* - * In a system that switches off the HZ timer nohz_cpu_mask - * indicates which cpus entered this state. This is used - * in the rcu update to wait only for active cpus. For system - * which do not switch off the HZ timer nohz_cpu_mask should - * always be CPU_BITS_NONE. - */ -cpumask_var_t nohz_cpu_mask; - -/* - * Increase the granularity value when there are more CPUs, - * because with more CPUs the 'effective latency' as visible - * to users decreases. But the relationship is not linear, - * so pick a second-best guess by going with the log2 of the - * number of CPUs. - * - * This idea comes from the SD scheduler of Con Kolivas: - */ -static inline void sched_init_granularity(void) -{ - unsigned int factor = 1 + ilog2(num_online_cpus()); - const unsigned long limit = 200000000; - - sysctl_sched_min_granularity *= factor; - if (sysctl_sched_min_granularity > limit) - sysctl_sched_min_granularity = limit; - - sysctl_sched_latency *= factor; - if (sysctl_sched_latency > limit) - sysctl_sched_latency = limit; - - sysctl_sched_wakeup_granularity *= factor; - - sysctl_sched_shares_ratelimit *= factor; -} - -#ifdef CONFIG_SMP -/* - * This is how migration works: - * - * 1) we queue a struct migration_req structure in the source CPU's - * runqueue and wake up that CPU's migration thread. - * 2) we down() the locked semaphore => thread blocks. - * 3) migration thread wakes up (implicitly it forces the migrated - * thread off the CPU) - * 4) it gets the migration request and checks whether the migrated - * task is still in the wrong runqueue. - * 5) if it's in the wrong runqueue then the migration thread removes - * it and puts it into the right queue. - * 6) migration thread up()s the semaphore. - * 7) we wake up and the migration is done. - */ - -/* - * Change a given task's CPU affinity. Migrate the thread to a - * proper CPU and schedule it away if the CPU it's executing on - * is removed from the allowed bitmask. - * - * NOTE: the caller must have a valid reference to the task, the - * task must not exit() & deallocate itself prematurely. The - * call is not atomic; no spinlocks may be held. - */ -int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask) -{ - struct migration_req req; - unsigned long flags; - struct rq *rq; - int ret = 0; - - rq = task_rq_lock(p, &flags); - if (!cpumask_intersects(new_mask, cpu_online_mask)) { - ret = -EINVAL; - goto out; - } - - if (unlikely((p->flags & PF_THREAD_BOUND) && p != current && - !cpumask_equal(&p->cpus_allowed, new_mask))) { - ret = -EINVAL; - goto out; - } - - if (p->sched_class->set_cpus_allowed) - p->sched_class->set_cpus_allowed(p, new_mask); - else { - cpumask_copy(&p->cpus_allowed, new_mask); - p->rt.nr_cpus_allowed = cpumask_weight(new_mask); - } - - /* Can the task run on the task's current CPU? If so, we're done */ - if (cpumask_test_cpu(task_cpu(p), new_mask)) - goto out; - - if (migrate_task(p, cpumask_any_and(cpu_online_mask, new_mask), &req)) { - /* Need help from migration thread: drop lock and wait. */ - task_rq_unlock(rq, &flags); - wake_up_process(rq->migration_thread); - wait_for_completion(&req.done); - tlb_migrate_finish(p->mm); - return 0; - } -out: - task_rq_unlock(rq, &flags); - - return ret; -} -EXPORT_SYMBOL_GPL(set_cpus_allowed_ptr); - -/* - * Move (not current) task off this cpu, onto dest cpu. We're doing - * this because either it can't run here any more (set_cpus_allowed() - * away from this CPU, or CPU going down), or because we're - * attempting to rebalance this task on exec (sched_exec). - * - * So we race with normal scheduler movements, but that's OK, as long - * as the task is no longer on this CPU. - * - * Returns non-zero if task was successfully migrated. - */ -static int __migrate_task(struct task_struct *p, int src_cpu, int dest_cpu) -{ - struct rq *rq_dest, *rq_src; - int ret = 0, on_rq; - - if (unlikely(!cpu_active(dest_cpu))) - return ret; - - rq_src = cpu_rq(src_cpu); - rq_dest = cpu_rq(dest_cpu); - - double_rq_lock(rq_src, rq_dest); - /* Already moved. */ - if (task_cpu(p) != src_cpu) - goto done; - /* Affinity changed (again). */ - if (!cpumask_test_cpu(dest_cpu, &p->cpus_allowed)) - goto fail; - - on_rq = p->se.on_rq; - if (on_rq) - deactivate_task(rq_src, p, 0); - - set_task_cpu(p, dest_cpu); - if (on_rq) { - activate_task(rq_dest, p, 0); - check_preempt_curr(rq_dest, p, 0); - } -done: - ret = 1; -fail: - double_rq_unlock(rq_src, rq_dest); - return ret; -} - -/* - * migration_thread - this is a highprio system thread that performs - * thread migration by bumping thread off CPU then 'pushing' onto - * another runqueue. - */ -static int migration_thread(void *data) -{ - int cpu = (long)data; - struct rq *rq; - - rq = cpu_rq(cpu); - BUG_ON(rq->migration_thread != current); - - set_current_state(TASK_INTERRUPTIBLE); - while (!kthread_should_stop()) { - struct migration_req *req; - struct list_head *head; - - spin_lock_irq(&rq->lock); - - if (cpu_is_offline(cpu)) { - spin_unlock_irq(&rq->lock); - goto wait_to_die; - } - - if (rq->active_balance) { - active_load_balance(rq, cpu); - rq->active_balance = 0; - } - - head = &rq->migration_queue; - - if (list_empty(head)) { - spin_unlock_irq(&rq->lock); - schedule(); - set_current_state(TASK_INTERRUPTIBLE); - continue; - } - req = list_entry(head->next, struct migration_req, list); - list_del_init(head->next); - - spin_unlock(&rq->lock); - __migrate_task(req->task, cpu, req->dest_cpu); - local_irq_enable(); - - complete(&req->done); - } - __set_current_state(TASK_RUNNING); - return 0; - -wait_to_die: - /* Wait for kthread_stop */ - set_current_state(TASK_INTERRUPTIBLE); - while (!kthread_should_stop()) { - schedule(); - set_current_state(TASK_INTERRUPTIBLE); - } - __set_current_state(TASK_RUNNING); - return 0; -} - -#ifdef CONFIG_HOTPLUG_CPU - -static int __migrate_task_irq(struct task_struct *p, int src_cpu, int dest_cpu) -{ - int ret; - - local_irq_disable(); - ret = __migrate_task(p, src_cpu, dest_cpu); - local_irq_enable(); - return ret; -} - -/* - * Figure out where task on dead CPU should go, use force if necessary. - */ -static void move_task_off_dead_cpu(int dead_cpu, struct task_struct *p) -{ - int dest_cpu; - const struct cpumask *nodemask = cpumask_of_node(cpu_to_node(dead_cpu)); - -again: - /* Look for allowed, online CPU in same node. */ - for_each_cpu_and(dest_cpu, nodemask, cpu_online_mask) - if (cpumask_test_cpu(dest_cpu, &p->cpus_allowed)) - goto move; - - /* Any allowed, online CPU? */ - dest_cpu = cpumask_any_and(&p->cpus_allowed, cpu_online_mask); - if (dest_cpu < nr_cpu_ids) - goto move; - - /* No more Mr. Nice Guy. */ - if (dest_cpu >= nr_cpu_ids) { - cpuset_cpus_allowed_locked(p, &p->cpus_allowed); - dest_cpu = cpumask_any_and(cpu_online_mask, &p->cpus_allowed); - - /* - * Don't tell them about moving exiting tasks or - * kernel threads (both mm NULL), since they never - * leave kernel. - */ - if (p->mm && printk_ratelimit()) { - printk(KERN_INFO "process %d (%s) no " - "longer affine to cpu%d\n", - task_pid_nr(p), p->comm, dead_cpu); - } - } - -move: - /* It can have affinity changed while we were choosing. */ - if (unlikely(!__migrate_task_irq(p, dead_cpu, dest_cpu))) - goto again; -} - -/* - * While a dead CPU has no uninterruptible tasks queued at this point, - * it might still have a nonzero ->nr_uninterruptible counter, because - * for performance reasons the counter is not stricly tracking tasks to - * their home CPUs. So we just add the counter to another CPU's counter, - * to keep the global sum constant after CPU-down: - */ -static void migrate_nr_uninterruptible(struct rq *rq_src) -{ - struct rq *rq_dest = cpu_rq(cpumask_any(cpu_online_mask)); - unsigned long flags; - - local_irq_save(flags); - double_rq_lock(rq_src, rq_dest); - rq_dest->nr_uninterruptible += rq_src->nr_uninterruptible; - rq_src->nr_uninterruptible = 0; - double_rq_unlock(rq_src, rq_dest); - local_irq_restore(flags); -} - -/* Run through task list and migrate tasks from the dead cpu. */ -static void migrate_live_tasks(int src_cpu) -{ - struct task_struct *p, *t; - - read_lock(&tasklist_lock); - - do_each_thread(t, p) { - if (p == current) - continue; - - if (task_cpu(p) == src_cpu) - move_task_off_dead_cpu(src_cpu, p); - } while_each_thread(t, p); - - read_unlock(&tasklist_lock); -} - -/* - * Schedules idle task to be the next runnable task on current CPU. - * It does so by boosting its priority to highest possible. - * Used by CPU offline code. - */ -void sched_idle_next(void) -{ - int this_cpu = smp_processor_id(); - struct rq *rq = cpu_rq(this_cpu); - struct task_struct *p = rq->idle; - unsigned long flags; - - /* cpu has to be offline */ - BUG_ON(cpu_online(this_cpu)); - - /* - * Strictly not necessary since rest of the CPUs are stopped by now - * and interrupts disabled on the current cpu. - */ - spin_lock_irqsave(&rq->lock, flags); - - __setscheduler(rq, p, SCHED_FIFO, MAX_RT_PRIO-1); - - update_rq_clock(rq); - activate_task(rq, p, 0); - - spin_unlock_irqrestore(&rq->lock, flags); -} - -/* - * Ensures that the idle task is using init_mm right before its cpu goes - * offline. - */ -void idle_task_exit(void) -{ - struct mm_struct *mm = current->active_mm; - - BUG_ON(cpu_online(smp_processor_id())); - - if (mm != &init_mm) - switch_mm(mm, &init_mm, current); - mmdrop(mm); -} - -/* called under rq->lock with disabled interrupts */ -static void migrate_dead(unsigned int dead_cpu, struct task_struct *p) -{ - struct rq *rq = cpu_rq(dead_cpu); - - /* Must be exiting, otherwise would be on tasklist. */ - BUG_ON(!p->exit_state); - - /* Cannot have done final schedule yet: would have vanished. */ - BUG_ON(p->state == TASK_DEAD); - - get_task_struct(p); - - /* - * Drop lock around migration; if someone else moves it, - * that's OK. No task can be added to this CPU, so iteration is - * fine. - */ - spin_unlock_irq(&rq->lock); - move_task_off_dead_cpu(dead_cpu, p); - spin_lock_irq(&rq->lock); - - put_task_struct(p); -} - -/* release_task() removes task from tasklist, so we won't find dead tasks. */ -static void migrate_dead_tasks(unsigned int dead_cpu) -{ - struct rq *rq = cpu_rq(dead_cpu); - struct task_struct *next; - - for ( ; ; ) { - if (!rq->nr_running) - break; - update_rq_clock(rq); - next = pick_next_task(rq); - if (!next) - break; - next->sched_class->put_prev_task(rq, next); - migrate_dead(dead_cpu, next); - - } -} -#endif /* CONFIG_HOTPLUG_CPU */ - -#if defined(CONFIG_SCHED_DEBUG) && defined(CONFIG_SYSCTL) - -static struct ctl_table sd_ctl_dir[] = { - { - .procname = "sched_domain", - .mode = 0555, - }, - {0, }, -}; - -static struct ctl_table sd_ctl_root[] = { - { - .ctl_name = CTL_KERN, - .procname = "kernel", - .mode = 0555, - .child = sd_ctl_dir, - }, - {0, }, -}; - -static struct ctl_table *sd_alloc_ctl_entry(int n) -{ - struct ctl_table *entry = - kcalloc(n, sizeof(struct ctl_table), GFP_KERNEL); - - return entry; -} - -static void sd_free_ctl_entry(struct ctl_table **tablep) -{ - struct ctl_table *entry; - - /* - * In the intermediate directories, both the child directory and - * procname are dynamically allocated and could fail but the mode - * will always be set. In the lowest directory the names are - * static strings and all have proc handlers. - */ - for (entry = *tablep; entry->mode; entry++) { - if (entry->child) - sd_free_ctl_entry(&entry->child); - if (entry->proc_handler == NULL) - kfree(entry->procname); - } - - kfree(*tablep); - *tablep = NULL; -} - -static void -set_table_entry(struct ctl_table *entry, - const char *procname, void *data, int maxlen, - mode_t mode, proc_handler *proc_handler) -{ - entry->procname = procname; - entry->data = data; - entry->maxlen = maxlen; - entry->mode = mode; - entry->proc_handler = proc_handler; -} - -static struct ctl_table * -sd_alloc_ctl_domain_table(struct sched_domain *sd) -{ - struct ctl_table *table = sd_alloc_ctl_entry(13); - - if (table == NULL) - return NULL; - - set_table_entry(&table[0], "min_interval", &sd->min_interval, - sizeof(long), 0644, proc_doulongvec_minmax); - set_table_entry(&table[1], "max_interval", &sd->max_interval, - sizeof(long), 0644, proc_doulongvec_minmax); - set_table_entry(&table[2], "busy_idx", &sd->busy_idx, - sizeof(int), 0644, proc_dointvec_minmax); - set_table_entry(&table[3], "idle_idx", &sd->idle_idx, - sizeof(int), 0644, proc_dointvec_minmax); - set_table_entry(&table[4], "newidle_idx", &sd->newidle_idx, - sizeof(int), 0644, proc_dointvec_minmax); - set_table_entry(&table[5], "wake_idx", &sd->wake_idx, - sizeof(int), 0644, proc_dointvec_minmax); - set_table_entry(&table[6], "forkexec_idx", &sd->forkexec_idx, - sizeof(int), 0644, proc_dointvec_minmax); - set_table_entry(&table[7], "busy_factor", &sd->busy_factor, - sizeof(int), 0644, proc_dointvec_minmax); - set_table_entry(&table[8], "imbalance_pct", &sd->imbalance_pct, - sizeof(int), 0644, proc_dointvec_minmax); - set_table_entry(&table[9], "cache_nice_tries", - &sd->cache_nice_tries, - sizeof(int), 0644, proc_dointvec_minmax); - set_table_entry(&table[10], "flags", &sd->flags, - sizeof(int), 0644, proc_dointvec_minmax); - set_table_entry(&table[11], "name", sd->name, - CORENAME_MAX_SIZE, 0444, proc_dostring); - /* &table[12] is terminator */ - - return table; -} - -static ctl_table *sd_alloc_ctl_cpu_table(int cpu) -{ - struct ctl_table *entry, *table; - struct sched_domain *sd; - int domain_num = 0, i; - char buf[32]; - - for_each_domain(cpu, sd) - domain_num++; - entry = table = sd_alloc_ctl_entry(domain_num + 1); - if (table == NULL) - return NULL; - - i = 0; - for_each_domain(cpu, sd) { - snprintf(buf, 32, "domain%d", i); - entry->procname = kstrdup(buf, GFP_KERNEL); - entry->mode = 0555; - entry->child = sd_alloc_ctl_domain_table(sd); - entry++; - i++; - } - return table; -} - -static struct ctl_table_header *sd_sysctl_header; -static void register_sched_domain_sysctl(void) -{ - int i, cpu_num = num_online_cpus(); - struct ctl_table *entry = sd_alloc_ctl_entry(cpu_num + 1); - char buf[32]; - - WARN_ON(sd_ctl_dir[0].child); - sd_ctl_dir[0].child = entry; - - if (entry == NULL) - return; - - for_each_online_cpu(i) { - snprintf(buf, 32, "cpu%d", i); - entry->procname = kstrdup(buf, GFP_KERNEL); - entry->mode = 0555; - entry->child = sd_alloc_ctl_cpu_table(i); - entry++; - } - - WARN_ON(sd_sysctl_header); - sd_sysctl_header = register_sysctl_table(sd_ctl_root); -} - -/* may be called multiple times per register */ -static void unregister_sched_domain_sysctl(void) -{ - if (sd_sysctl_header) - unregister_sysctl_table(sd_sysctl_header); - sd_sysctl_header = NULL; - if (sd_ctl_dir[0].child) - sd_free_ctl_entry(&sd_ctl_dir[0].child); -} -#else -static void register_sched_domain_sysctl(void) -{ -} -static void unregister_sched_domain_sysctl(void) -{ -} -#endif - -static void set_rq_online(struct rq *rq) -{ - if (!rq->online) { - const struct sched_class *class; - - cpumask_set_cpu(rq->cpu, rq->rd->online); - rq->online = 1; - - for_each_class(class) { - if (class->rq_online) - class->rq_online(rq); - } - } -} - -static void set_rq_offline(struct rq *rq) -{ - if (rq->online) { - const struct sched_class *class; - - for_each_class(class) { - if (class->rq_offline) - class->rq_offline(rq); - } - - cpumask_clear_cpu(rq->cpu, rq->rd->online); - rq->online = 0; - } -} - -/* - * migration_call - callback that gets triggered when a CPU is added. - * Here we can start up the necessary migration thread for the new CPU. - */ -static int __cpuinit -migration_call(struct notifier_block *nfb, unsigned long action, void *hcpu) -{ - struct task_struct *p; - int cpu = (long)hcpu; - unsigned long flags; - struct rq *rq; - - switch (action) { - - case CPU_UP_PREPARE: - case CPU_UP_PREPARE_FROZEN: - p = kthread_create(migration_thread, hcpu, "migration/%d", cpu); - if (IS_ERR(p)) - return NOTIFY_BAD; - kthread_bind(p, cpu); - /* Must be high prio: stop_machine expects to yield to it. */ - rq = task_rq_lock(p, &flags); - __setscheduler(rq, p, SCHED_FIFO, MAX_RT_PRIO-1); - task_rq_unlock(rq, &flags); - cpu_rq(cpu)->migration_thread = p; - break; - - case CPU_ONLINE: - case CPU_ONLINE_FROZEN: - /* Strictly unnecessary, as first user will wake it. */ - wake_up_process(cpu_rq(cpu)->migration_thread); - - /* Update our root-domain */ - rq = cpu_rq(cpu); - spin_lock_irqsave(&rq->lock, flags); - if (rq->rd) { - BUG_ON(!cpumask_test_cpu(cpu, rq->rd->span)); - - set_rq_online(rq); - } - spin_unlock_irqrestore(&rq->lock, flags); - break; - -#ifdef CONFIG_HOTPLUG_CPU - case CPU_UP_CANCELED: - case CPU_UP_CANCELED_FROZEN: - if (!cpu_rq(cpu)->migration_thread) - break; - /* Unbind it from offline cpu so it can run. Fall thru. */ - kthread_bind(cpu_rq(cpu)->migration_thread, - cpumask_any(cpu_online_mask)); - kthread_stop(cpu_rq(cpu)->migration_thread); - cpu_rq(cpu)->migration_thread = NULL; - break; - - case CPU_DEAD: - case CPU_DEAD_FROZEN: - cpuset_lock(); /* around calls to cpuset_cpus_allowed_lock() */ - migrate_live_tasks(cpu); - rq = cpu_rq(cpu); - kthread_stop(rq->migration_thread); - rq->migration_thread = NULL; - /* Idle task back to normal (off runqueue, low prio) */ - spin_lock_irq(&rq->lock); - update_rq_clock(rq); - deactivate_task(rq, rq->idle, 0); - rq->idle->static_prio = MAX_PRIO; - __setscheduler(rq, rq->idle, SCHED_NORMAL, 0); - rq->idle->sched_class = &idle_sched_class; - migrate_dead_tasks(cpu); - spin_unlock_irq(&rq->lock); - cpuset_unlock(); - migrate_nr_uninterruptible(rq); - BUG_ON(rq->nr_running != 0); - - /* - * No need to migrate the tasks: it was best-effort if - * they didn't take sched_hotcpu_mutex. Just wake up - * the requestors. - */ - spin_lock_irq(&rq->lock); - while (!list_empty(&rq->migration_queue)) { - struct migration_req *req; - - req = list_entry(rq->migration_queue.next, - struct migration_req, list); - list_del_init(&req->list); - spin_unlock_irq(&rq->lock); - complete(&req->done); - spin_lock_irq(&rq->lock); - } - spin_unlock_irq(&rq->lock); - break; - - case CPU_DYING: - case CPU_DYING_FROZEN: - /* Update our root-domain */ - rq = cpu_rq(cpu); - spin_lock_irqsave(&rq->lock, flags); - if (rq->rd) { - BUG_ON(!cpumask_test_cpu(cpu, rq->rd->span)); - set_rq_offline(rq); - } - spin_unlock_irqrestore(&rq->lock, flags); - break; -#endif - } - return NOTIFY_OK; -} - -/* Register at highest priority so that task migration (migrate_all_tasks) - * happens before everything else. - */ -static struct notifier_block __cpuinitdata migration_notifier = { - .notifier_call = migration_call, - .priority = 10 -}; - -static int __init migration_init(void) -{ - void *cpu = (void *)(long)smp_processor_id(); - int err; - - /* Start one for the boot CPU: */ - err = migration_call(&migration_notifier, CPU_UP_PREPARE, cpu); - BUG_ON(err == NOTIFY_BAD); - migration_call(&migration_notifier, CPU_ONLINE, cpu); - register_cpu_notifier(&migration_notifier); - - return err; -} -early_initcall(migration_init); -#endif - -#ifdef CONFIG_SMP - -#ifdef CONFIG_SCHED_DEBUG - -static int sched_domain_debug_one(struct sched_domain *sd, int cpu, int level, - struct cpumask *groupmask) -{ - struct sched_group *group = sd->groups; - char str[256]; - - cpulist_scnprintf(str, sizeof(str), sched_domain_span(sd)); - cpumask_clear(groupmask); - - printk(KERN_DEBUG "%*s domain %d: ", level, "", level); - - if (!(sd->flags & SD_LOAD_BALANCE)) { - printk("does not load-balance\n"); - if (sd->parent) - printk(KERN_ERR "ERROR: !SD_LOAD_BALANCE domain" - " has parent"); - return -1; - } - - printk(KERN_CONT "span %s level %s\n", str, sd->name); - - if (!cpumask_test_cpu(cpu, sched_domain_span(sd))) { - printk(KERN_ERR "ERROR: domain->span does not contain " - "CPU%d\n", cpu); - } - if (!cpumask_test_cpu(cpu, sched_group_cpus(group))) { - printk(KERN_ERR "ERROR: domain->groups does not contain" - " CPU%d\n", cpu); - } - - printk(KERN_DEBUG "%*s groups:", level + 1, ""); - do { - if (!group) { - printk("\n"); - printk(KERN_ERR "ERROR: group is NULL\n"); - break; - } - - if (!group->__cpu_power) { - printk(KERN_CONT "\n"); - printk(KERN_ERR "ERROR: domain->cpu_power not " - "set\n"); - break; - } - - if (!cpumask_weight(sched_group_cpus(group))) { - printk(KERN_CONT "\n"); - printk(KERN_ERR "ERROR: empty group\n"); - break; - } - - if (cpumask_intersects(groupmask, sched_group_cpus(group))) { - printk(KERN_CONT "\n"); - printk(KERN_ERR "ERROR: repeated CPUs\n"); - break; - } - - cpumask_or(groupmask, groupmask, sched_group_cpus(group)); - - cpulist_scnprintf(str, sizeof(str), sched_group_cpus(group)); - - printk(KERN_CONT " %s", str); - if (group->__cpu_power != SCHED_LOAD_SCALE) { - printk(KERN_CONT " (__cpu_power = %d)", - group->__cpu_power); - } - - group = group->next; - } while (group != sd->groups); - printk(KERN_CONT "\n"); - - if (!cpumask_equal(sched_domain_span(sd), groupmask)) - printk(KERN_ERR "ERROR: groups don't span domain->span\n"); - - if (sd->parent && - !cpumask_subset(groupmask, sched_domain_span(sd->parent))) - printk(KERN_ERR "ERROR: parent span is not a superset " - "of domain->span\n"); - return 0; -} - -static void sched_domain_debug(struct sched_domain *sd, int cpu) -{ - cpumask_var_t groupmask; - int level = 0; - - if (!sd) { - printk(KERN_DEBUG "CPU%d attaching NULL sched-domain.\n", cpu); - return; - } - - printk(KERN_DEBUG "CPU%d attaching sched-domain:\n", cpu); - - if (!alloc_cpumask_var(&groupmask, GFP_KERNEL)) { - printk(KERN_DEBUG "Cannot load-balance (out of memory)\n"); - return; - } - - for (;;) { - if (sched_domain_debug_one(sd, cpu, level, groupmask)) - break; - level++; - sd = sd->parent; - if (!sd) - break; - } - free_cpumask_var(groupmask); -} -#else /* !CONFIG_SCHED_DEBUG */ -# define sched_domain_debug(sd, cpu) do { } while (0) -#endif /* CONFIG_SCHED_DEBUG */ - -static int sd_degenerate(struct sched_domain *sd) -{ - if (cpumask_weight(sched_domain_span(sd)) == 1) - return 1; - - /* Following flags need at least 2 groups */ - if (sd->flags & (SD_LOAD_BALANCE | - SD_BALANCE_NEWIDLE | - SD_BALANCE_FORK | - SD_BALANCE_EXEC | - SD_SHARE_CPUPOWER | - SD_SHARE_PKG_RESOURCES)) { - if (sd->groups != sd->groups->next) - return 0; - } - - /* Following flags don't use groups */ - if (sd->flags & (SD_WAKE_IDLE | - SD_WAKE_AFFINE | - SD_WAKE_BALANCE)) - return 0; - - return 1; -} - -static int -sd_parent_degenerate(struct sched_domain *sd, struct sched_domain *parent) -{ - unsigned long cflags = sd->flags, pflags = parent->flags; - - if (sd_degenerate(parent)) - return 1; - - if (!cpumask_equal(sched_domain_span(sd), sched_domain_span(parent))) - return 0; - - /* Does parent contain flags not in child? */ - /* WAKE_BALANCE is a subset of WAKE_AFFINE */ - if (cflags & SD_WAKE_AFFINE) - pflags &= ~SD_WAKE_BALANCE; - /* Flags needing groups don't count if only 1 group in parent */ - if (parent->groups == parent->groups->next) { - pflags &= ~(SD_LOAD_BALANCE | - SD_BALANCE_NEWIDLE | - SD_BALANCE_FORK | - SD_BALANCE_EXEC | - SD_SHARE_CPUPOWER | - SD_SHARE_PKG_RESOURCES); - if (nr_node_ids == 1) - pflags &= ~SD_SERIALIZE; - } - if (~cflags & pflags) - return 0; - - return 1; -} - -static void free_rootdomain(struct root_domain *rd) -{ - cpupri_cleanup(&rd->cpupri); - - free_cpumask_var(rd->rto_mask); - free_cpumask_var(rd->online); - free_cpumask_var(rd->span); - kfree(rd); -} - -static void rq_attach_root(struct rq *rq, struct root_domain *rd) -{ - struct root_domain *old_rd = NULL; - unsigned long flags; - - spin_lock_irqsave(&rq->lock, flags); - - if (rq->rd) { - old_rd = rq->rd; - - if (cpumask_test_cpu(rq->cpu, old_rd->online)) - set_rq_offline(rq); - - cpumask_clear_cpu(rq->cpu, old_rd->span); - - /* - * If we dont want to free the old_rt yet then - * set old_rd to NULL to skip the freeing later - * in this function: - */ - if (!atomic_dec_and_test(&old_rd->refcount)) - old_rd = NULL; - } - - atomic_inc(&rd->refcount); - rq->rd = rd; - - cpumask_set_cpu(rq->cpu, rd->span); - if (cpumask_test_cpu(rq->cpu, cpu_online_mask)) - set_rq_online(rq); - - spin_unlock_irqrestore(&rq->lock, flags); - - if (old_rd) - free_rootdomain(old_rd); -} - -static int __init_refok init_rootdomain(struct root_domain *rd, bool bootmem) -{ - memset(rd, 0, sizeof(*rd)); - - if (bootmem) { - alloc_bootmem_cpumask_var(&def_root_domain.span); - alloc_bootmem_cpumask_var(&def_root_domain.online); - alloc_bootmem_cpumask_var(&def_root_domain.rto_mask); - cpupri_init(&rd->cpupri, true); - return 0; - } - - if (!alloc_cpumask_var(&rd->span, GFP_KERNEL)) - goto out; - if (!alloc_cpumask_var(&rd->online, GFP_KERNEL)) - goto free_span; - if (!alloc_cpumask_var(&rd->rto_mask, GFP_KERNEL)) - goto free_online; - - if (cpupri_init(&rd->cpupri, false) != 0) - goto free_rto_mask; - return 0; - -free_rto_mask: - free_cpumask_var(rd->rto_mask); -free_online: - free_cpumask_var(rd->online); -free_span: - free_cpumask_var(rd->span); -out: - return -ENOMEM; -} - -static void init_defrootdomain(void) -{ - init_rootdomain(&def_root_domain, true); - - atomic_set(&def_root_domain.refcount, 1); -} - -static struct root_domain *alloc_rootdomain(void) -{ - struct root_domain *rd; - - rd = kmalloc(sizeof(*rd), GFP_KERNEL); - if (!rd) - return NULL; - - if (init_rootdomain(rd, false) != 0) { - kfree(rd); - return NULL; - } - - return rd; -} - -/* - * Attach the domain 'sd' to 'cpu' as its base domain. Callers must - * hold the hotplug lock. - */ -static void -cpu_attach_domain(struct sched_domain *sd, struct root_domain *rd, int cpu) -{ - struct rq *rq = cpu_rq(cpu); - struct sched_domain *tmp; - - /* Remove the sched domains which do not contribute to scheduling. */ - for (tmp = sd; tmp; ) { - struct sched_domain *parent = tmp->parent; - if (!parent) - break; - - if (sd_parent_degenerate(tmp, parent)) { - tmp->parent = parent->parent; - if (parent->parent) - parent->parent->child = tmp; - } else - tmp = tmp->parent; - } - - if (sd && sd_degenerate(sd)) { - sd = sd->parent; - if (sd) - sd->child = NULL; - } - - sched_domain_debug(sd, cpu); - - rq_attach_root(rq, rd); - rcu_assign_pointer(rq->sd, sd); -} - -/* cpus with isolated domains */ -static cpumask_var_t cpu_isolated_map; - -/* Setup the mask of cpus configured for isolated domains */ -static int __init isolated_cpu_setup(char *str) -{ - cpulist_parse(str, cpu_isolated_map); - return 1; -} - -__setup("isolcpus=", isolated_cpu_setup); - -/* - * init_sched_build_groups takes the cpumask we wish to span, and a pointer - * to a function which identifies what group(along with sched group) a CPU - * belongs to. The return value of group_fn must be a >= 0 and < nr_cpu_ids - * (due to the fact that we keep track of groups covered with a struct cpumask). - * - * init_sched_build_groups will build a circular linked list of the groups - * covered by the given span, and will set each group's ->cpumask correctly, - * and ->cpu_power to 0. - */ -static void -init_sched_build_groups(const struct cpumask *span, - const struct cpumask *cpu_map, - int (*group_fn)(int cpu, const struct cpumask *cpu_map, - struct sched_group **sg, - struct cpumask *tmpmask), - struct cpumask *covered, struct cpumask *tmpmask) -{ - struct sched_group *first = NULL, *last = NULL; - int i; - - cpumask_clear(covered); - - for_each_cpu(i, span) { - struct sched_group *sg; - int group = group_fn(i, cpu_map, &sg, tmpmask); - int j; - - if (cpumask_test_cpu(i, covered)) - continue; - - cpumask_clear(sched_group_cpus(sg)); - sg->__cpu_power = 0; - - for_each_cpu(j, span) { - if (group_fn(j, cpu_map, NULL, tmpmask) != group) - continue; - - cpumask_set_cpu(j, covered); - cpumask_set_cpu(j, sched_group_cpus(sg)); - } - if (!first) - first = sg; - if (last) - last->next = sg; - last = sg; - } - last->next = first; -} - -#define SD_NODES_PER_DOMAIN 16 - -#ifdef CONFIG_NUMA - -/** - * find_next_best_node - find the next node to include in a sched_domain - * @node: node whose sched_domain we're building - * @used_nodes: nodes already in the sched_domain - * - * Find the next node to include in a given scheduling domain. Simply - * finds the closest node not already in the @used_nodes map. - * - * Should use nodemask_t. - */ -static int find_next_best_node(int node, nodemask_t *used_nodes) -{ - int i, n, val, min_val, best_node = 0; - - min_val = INT_MAX; - - for (i = 0; i < nr_node_ids; i++) { - /* Start at @node */ - n = (node + i) % nr_node_ids; - - if (!nr_cpus_node(n)) - continue; - - /* Skip already used nodes */ - if (node_isset(n, *used_nodes)) - continue; - - /* Simple min distance search */ - val = node_distance(node, n); - - if (val < min_val) { - min_val = val; - best_node = n; - } - } - - node_set(best_node, *used_nodes); - return best_node; -} - -/** - * sched_domain_node_span - get a cpumask for a node's sched_domain - * @node: node whose cpumask we're constructing - * @span: resulting cpumask - * - * Given a node, construct a good cpumask for its sched_domain to span. It - * should be one that prevents unnecessary balancing, but also spreads tasks - * out optimally. - */ -static void sched_domain_node_span(int node, struct cpumask *span) -{ - nodemask_t used_nodes; - int i; - - cpumask_clear(span); - nodes_clear(used_nodes); - - cpumask_or(span, span, cpumask_of_node(node)); - node_set(node, used_nodes); - - for (i = 1; i < SD_NODES_PER_DOMAIN; i++) { - int next_node = find_next_best_node(node, &used_nodes); - - cpumask_or(span, span, cpumask_of_node(next_node)); - } -} -#endif /* CONFIG_NUMA */ - -int sched_smt_power_savings = 0, sched_mc_power_savings = 0; - -/* - * The cpus mask in sched_group and sched_domain hangs off the end. - * FIXME: use cpumask_var_t or dynamic percpu alloc to avoid wasting space - * for nr_cpu_ids < CONFIG_NR_CPUS. - */ -struct static_sched_group { - struct sched_group sg; - DECLARE_BITMAP(cpus, CONFIG_NR_CPUS); -}; - -struct static_sched_domain { - struct sched_domain sd; - DECLARE_BITMAP(span, CONFIG_NR_CPUS); -}; - -/* - * SMT sched-domains: - */ -#ifdef CONFIG_SCHED_SMT -static DEFINE_PER_CPU(struct static_sched_domain, cpu_domains); -static DEFINE_PER_CPU(struct static_sched_group, sched_group_cpus); - -static int -cpu_to_cpu_group(int cpu, const struct cpumask *cpu_map, - struct sched_group **sg, struct cpumask *unused) -{ - if (sg) - *sg = &per_cpu(sched_group_cpus, cpu).sg; - return cpu; -} -#endif /* CONFIG_SCHED_SMT */ - -/* - * multi-core sched-domains: - */ -#ifdef CONFIG_SCHED_MC -static DEFINE_PER_CPU(struct static_sched_domain, core_domains); -static DEFINE_PER_CPU(struct static_sched_group, sched_group_core); -#endif /* CONFIG_SCHED_MC */ - -#if defined(CONFIG_SCHED_MC) && defined(CONFIG_SCHED_SMT) -static int -cpu_to_core_group(int cpu, const struct cpumask *cpu_map, - struct sched_group **sg, struct cpumask *mask) -{ - int group; - - cpumask_and(mask, topology_thread_cpumask(cpu), cpu_map); - group = cpumask_first(mask); - if (sg) - *sg = &per_cpu(sched_group_core, group).sg; - return group; -} -#elif defined(CONFIG_SCHED_MC) -static int -cpu_to_core_group(int cpu, const struct cpumask *cpu_map, - struct sched_group **sg, struct cpumask *unused) -{ - if (sg) - *sg = &per_cpu(sched_group_core, cpu).sg; - return cpu; -} -#endif - -static DEFINE_PER_CPU(struct static_sched_domain, phys_domains); -static DEFINE_PER_CPU(struct static_sched_group, sched_group_phys); - -static int -cpu_to_phys_group(int cpu, const struct cpumask *cpu_map, - struct sched_group **sg, struct cpumask *mask) -{ - int group; -#ifdef CONFIG_SCHED_MC - cpumask_and(mask, cpu_coregroup_mask(cpu), cpu_map); - group = cpumask_first(mask); -#elif defined(CONFIG_SCHED_SMT) - cpumask_and(mask, topology_thread_cpumask(cpu), cpu_map); - group = cpumask_first(mask); -#else - group = cpu; -#endif - if (sg) - *sg = &per_cpu(sched_group_phys, group).sg; - return group; -} - -#ifdef CONFIG_NUMA -/* - * The init_sched_build_groups can't handle what we want to do with node - * groups, so roll our own. Now each node has its own list of groups which - * gets dynamically allocated. - */ -static DEFINE_PER_CPU(struct static_sched_domain, node_domains); -static struct sched_group ***sched_group_nodes_bycpu; - -static DEFINE_PER_CPU(struct static_sched_domain, allnodes_domains); -static DEFINE_PER_CPU(struct static_sched_group, sched_group_allnodes); - -static int cpu_to_allnodes_group(int cpu, const struct cpumask *cpu_map, - struct sched_group **sg, - struct cpumask *nodemask) -{ - int group; - - cpumask_and(nodemask, cpumask_of_node(cpu_to_node(cpu)), cpu_map); - group = cpumask_first(nodemask); - - if (sg) - *sg = &per_cpu(sched_group_allnodes, group).sg; - return group; -} - -static void init_numa_sched_groups_power(struct sched_group *group_head) -{ - struct sched_group *sg = group_head; - int j; - - if (!sg) - return; - do { - for_each_cpu(j, sched_group_cpus(sg)) { - struct sched_domain *sd; - - sd = &per_cpu(phys_domains, j).sd; - if (j != cpumask_first(sched_group_cpus(sd->groups))) { - /* - * Only add "power" once for each - * physical package. - */ - continue; - } - - sg_inc_cpu_power(sg, sd->groups->__cpu_power); - } - sg = sg->next; - } while (sg != group_head); -} -#endif /* CONFIG_NUMA */ - -#ifdef CONFIG_NUMA -/* Free memory allocated for various sched_group structures */ -static void free_sched_groups(const struct cpumask *cpu_map, - struct cpumask *nodemask) -{ - int cpu, i; - - for_each_cpu(cpu, cpu_map) { - struct sched_group **sched_group_nodes - = sched_group_nodes_bycpu[cpu]; - - if (!sched_group_nodes) - continue; - - for (i = 0; i < nr_node_ids; i++) { - struct sched_group *oldsg, *sg = sched_group_nodes[i]; - - cpumask_and(nodemask, cpumask_of_node(i), cpu_map); - if (cpumask_empty(nodemask)) - continue; - - if (sg == NULL) - continue; - sg = sg->next; -next_sg: - oldsg = sg; - sg = sg->next; - kfree(oldsg); - if (oldsg != sched_group_nodes[i]) - goto next_sg; - } - kfree(sched_group_nodes); - sched_group_nodes_bycpu[cpu] = NULL; - } -} -#else /* !CONFIG_NUMA */ -static void free_sched_groups(const struct cpumask *cpu_map, - struct cpumask *nodemask) -{ -} -#endif /* CONFIG_NUMA */ - -/* - * Initialize sched groups cpu_power. - * - * cpu_power indicates the capacity of sched group, which is used while - * distributing the load between different sched groups in a sched domain. - * Typically cpu_power for all the groups in a sched domain will be same unless - * there are asymmetries in the topology. If there are asymmetries, group - * having more cpu_power will pickup more load compared to the group having - * less cpu_power. - * - * cpu_power will be a multiple of SCHED_LOAD_SCALE. This multiple represents - * the maximum number of tasks a group can handle in the presence of other idle - * or lightly loaded groups in the same sched domain. - */ -static void init_sched_groups_power(int cpu, struct sched_domain *sd) -{ - struct sched_domain *child; - struct sched_group *group; - - WARN_ON(!sd || !sd->groups); - - if (cpu != cpumask_first(sched_group_cpus(sd->groups))) - return; - - child = sd->child; - - sd->groups->__cpu_power = 0; - - /* - * For perf policy, if the groups in child domain share resources - * (for example cores sharing some portions of the cache hierarchy - * or SMT), then set this domain groups cpu_power such that each group - * can handle only one task, when there are other idle groups in the - * same sched domain. - */ - if (!child || (!(sd->flags & SD_POWERSAVINGS_BALANCE) && - (child->flags & - (SD_SHARE_CPUPOWER | SD_SHARE_PKG_RESOURCES)))) { - sg_inc_cpu_power(sd->groups, SCHED_LOAD_SCALE); - return; - } - - /* - * add cpu_power of each child group to this groups cpu_power - */ - group = child->groups; - do { - sg_inc_cpu_power(sd->groups, group->__cpu_power); - group = group->next; - } while (group != child->groups); -} - -/* - * Initializers for schedule domains - * Non-inlined to reduce accumulated stack pressure in build_sched_domains() - */ - -#ifdef CONFIG_SCHED_DEBUG -# define SD_INIT_NAME(sd, type) sd->name = #type -#else -# define SD_INIT_NAME(sd, type) do { } while (0) -#endif - -#define SD_INIT(sd, type) sd_init_##type(sd) - -#define SD_INIT_FUNC(type) \ -static noinline void sd_init_##type(struct sched_domain *sd) \ -{ \ - memset(sd, 0, sizeof(*sd)); \ - *sd = SD_##type##_INIT; \ - sd->level = SD_LV_##type; \ - SD_INIT_NAME(sd, type); \ -} - -SD_INIT_FUNC(CPU) -#ifdef CONFIG_NUMA - SD_INIT_FUNC(ALLNODES) - SD_INIT_FUNC(NODE) -#endif -#ifdef CONFIG_SCHED_SMT - SD_INIT_FUNC(SIBLING) -#endif -#ifdef CONFIG_SCHED_MC - SD_INIT_FUNC(MC) -#endif - -static int default_relax_domain_level = -1; - -static int __init setup_relax_domain_level(char *str) -{ - unsigned long val; - - val = simple_strtoul(str, NULL, 0); - if (val < SD_LV_MAX) - default_relax_domain_level = val; - - return 1; -} -__setup("relax_domain_level=", setup_relax_domain_level); - -static void set_domain_attribute(struct sched_domain *sd, - struct sched_domain_attr *attr) -{ - int request; - - if (!attr || attr->relax_domain_level < 0) { - if (default_relax_domain_level < 0) - return; - else - request = default_relax_domain_level; - } else - request = attr->relax_domain_level; - if (request < sd->level) { - /* turn off idle balance on this domain */ - sd->flags &= ~(SD_WAKE_IDLE|SD_BALANCE_NEWIDLE); - } else { - /* turn on idle balance on this domain */ - sd->flags |= (SD_WAKE_IDLE_FAR|SD_BALANCE_NEWIDLE); - } -} - -/* - * Build sched domains for a given set of cpus and attach the sched domains - * to the individual cpus - */ -static int __build_sched_domains(const struct cpumask *cpu_map, - struct sched_domain_attr *attr) -{ - int i, err = -ENOMEM; - struct root_domain *rd; - cpumask_var_t nodemask, this_sibling_map, this_core_map, send_covered, - tmpmask; -#ifdef CONFIG_NUMA - cpumask_var_t domainspan, covered, notcovered; - struct sched_group **sched_group_nodes = NULL; - int sd_allnodes = 0; - - if (!alloc_cpumask_var(&domainspan, GFP_KERNEL)) - goto out; - if (!alloc_cpumask_var(&covered, GFP_KERNEL)) - goto free_domainspan; - if (!alloc_cpumask_var(¬covered, GFP_KERNEL)) - goto free_covered; -#endif - - if (!alloc_cpumask_var(&nodemask, GFP_KERNEL)) - goto free_notcovered; - if (!alloc_cpumask_var(&this_sibling_map, GFP_KERNEL)) - goto free_nodemask; - if (!alloc_cpumask_var(&this_core_map, GFP_KERNEL)) - goto free_this_sibling_map; - if (!alloc_cpumask_var(&send_covered, GFP_KERNEL)) - goto free_this_core_map; - if (!alloc_cpumask_var(&tmpmask, GFP_KERNEL)) - goto free_send_covered; - -#ifdef CONFIG_NUMA - /* - * Allocate the per-node list of sched groups - */ - sched_group_nodes = kcalloc(nr_node_ids, sizeof(struct sched_group *), - GFP_KERNEL); - if (!sched_group_nodes) { - printk(KERN_WARNING "Can not alloc sched group node list\n"); - goto free_tmpmask; - } -#endif - - rd = alloc_rootdomain(); - if (!rd) { - printk(KERN_WARNING "Cannot alloc root domain\n"); - goto free_sched_groups; - } - -#ifdef CONFIG_NUMA - sched_group_nodes_bycpu[cpumask_first(cpu_map)] = sched_group_nodes; -#endif - - /* - * Set up domains for cpus specified by the cpu_map. - */ - for_each_cpu(i, cpu_map) { - struct sched_domain *sd = NULL, *p; - - cpumask_and(nodemask, cpumask_of_node(cpu_to_node(i)), cpu_map); - -#ifdef CONFIG_NUMA - if (cpumask_weight(cpu_map) > - SD_NODES_PER_DOMAIN*cpumask_weight(nodemask)) { - sd = &per_cpu(allnodes_domains, i).sd; - SD_INIT(sd, ALLNODES); - set_domain_attribute(sd, attr); - cpumask_copy(sched_domain_span(sd), cpu_map); - cpu_to_allnodes_group(i, cpu_map, &sd->groups, tmpmask); - p = sd; - sd_allnodes = 1; - } else - p = NULL; - - sd = &per_cpu(node_domains, i).sd; - SD_INIT(sd, NODE); - set_domain_attribute(sd, attr); - sched_domain_node_span(cpu_to_node(i), sched_domain_span(sd)); - sd->parent = p; - if (p) - p->child = sd; - cpumask_and(sched_domain_span(sd), - sched_domain_span(sd), cpu_map); -#endif - - p = sd; - sd = &per_cpu(phys_domains, i).sd; - SD_INIT(sd, CPU); - set_domain_attribute(sd, attr); - cpumask_copy(sched_domain_span(sd), nodemask); - sd->parent = p; - if (p) - p->child = sd; - cpu_to_phys_group(i, cpu_map, &sd->groups, tmpmask); - -#ifdef CONFIG_SCHED_MC - p = sd; - sd = &per_cpu(core_domains, i).sd; - SD_INIT(sd, MC); - set_domain_attribute(sd, attr); - cpumask_and(sched_domain_span(sd), cpu_map, - cpu_coregroup_mask(i)); - sd->parent = p; - p->child = sd; - cpu_to_core_group(i, cpu_map, &sd->groups, tmpmask); -#endif - -#ifdef CONFIG_SCHED_SMT - p = sd; - sd = &per_cpu(cpu_domains, i).sd; - SD_INIT(sd, SIBLING); - set_domain_attribute(sd, attr); - cpumask_and(sched_domain_span(sd), - topology_thread_cpumask(i), cpu_map); - sd->parent = p; - p->child = sd; - cpu_to_cpu_group(i, cpu_map, &sd->groups, tmpmask); -#endif - } - -#ifdef CONFIG_SCHED_SMT - /* Set up CPU (sibling) groups */ - for_each_cpu(i, cpu_map) { - cpumask_and(this_sibling_map, - topology_thread_cpumask(i), cpu_map); - if (i != cpumask_first(this_sibling_map)) - continue; - - init_sched_build_groups(this_sibling_map, cpu_map, - &cpu_to_cpu_group, - send_covered, tmpmask); - } -#endif - -#ifdef CONFIG_SCHED_MC - /* Set up multi-core groups */ - for_each_cpu(i, cpu_map) { - cpumask_and(this_core_map, cpu_coregroup_mask(i), cpu_map); - if (i != cpumask_first(this_core_map)) - continue; - - init_sched_build_groups(this_core_map, cpu_map, - &cpu_to_core_group, - send_covered, tmpmask); - } -#endif - - /* Set up physical groups */ - for (i = 0; i < nr_node_ids; i++) { - cpumask_and(nodemask, cpumask_of_node(i), cpu_map); - if (cpumask_empty(nodemask)) - continue; - - init_sched_build_groups(nodemask, cpu_map, - &cpu_to_phys_group, - send_covered, tmpmask); - } - -#ifdef CONFIG_NUMA - /* Set up node groups */ - if (sd_allnodes) { - init_sched_build_groups(cpu_map, cpu_map, - &cpu_to_allnodes_group, - send_covered, tmpmask); - } - - for (i = 0; i < nr_node_ids; i++) { - /* Set up node groups */ - struct sched_group *sg, *prev; - int j; - - cpumask_clear(covered); - cpumask_and(nodemask, cpumask_of_node(i), cpu_map); - if (cpumask_empty(nodemask)) { - sched_group_nodes[i] = NULL; - continue; - } - - sched_domain_node_span(i, domainspan); - cpumask_and(domainspan, domainspan, cpu_map); - - sg = kmalloc_node(sizeof(struct sched_group) + cpumask_size(), - GFP_KERNEL, i); - if (!sg) { - printk(KERN_WARNING "Can not alloc domain group for " - "node %d\n", i); - goto error; - } - sched_group_nodes[i] = sg; - for_each_cpu(j, nodemask) { - struct sched_domain *sd; - - sd = &per_cpu(node_domains, j).sd; - sd->groups = sg; - } - sg->__cpu_power = 0; - cpumask_copy(sched_group_cpus(sg), nodemask); - sg->next = sg; - cpumask_or(covered, covered, nodemask); - prev = sg; - - for (j = 0; j < nr_node_ids; j++) { - int n = (i + j) % nr_node_ids; - - cpumask_complement(notcovered, covered); - cpumask_and(tmpmask, notcovered, cpu_map); - cpumask_and(tmpmask, tmpmask, domainspan); - if (cpumask_empty(tmpmask)) - break; - - cpumask_and(tmpmask, tmpmask, cpumask_of_node(n)); - if (cpumask_empty(tmpmask)) - continue; - - sg = kmalloc_node(sizeof(struct sched_group) + - cpumask_size(), - GFP_KERNEL, i); - if (!sg) { - printk(KERN_WARNING - "Can not alloc domain group for node %d\n", j); - goto error; - } - sg->__cpu_power = 0; - cpumask_copy(sched_group_cpus(sg), tmpmask); - sg->next = prev->next; - cpumask_or(covered, covered, tmpmask); - prev->next = sg; - prev = sg; - } - } -#endif - - /* Calculate CPU power for physical packages and nodes */ -#ifdef CONFIG_SCHED_SMT - for_each_cpu(i, cpu_map) { - struct sched_domain *sd = &per_cpu(cpu_domains, i).sd; - - init_sched_groups_power(i, sd); - } -#endif -#ifdef CONFIG_SCHED_MC - for_each_cpu(i, cpu_map) { - struct sched_domain *sd = &per_cpu(core_domains, i).sd; - - init_sched_groups_power(i, sd); - } -#endif - - for_each_cpu(i, cpu_map) { - struct sched_domain *sd = &per_cpu(phys_domains, i).sd; - - init_sched_groups_power(i, sd); - } - -#ifdef CONFIG_NUMA - for (i = 0; i < nr_node_ids; i++) - init_numa_sched_groups_power(sched_group_nodes[i]); - - if (sd_allnodes) { - struct sched_group *sg; - - cpu_to_allnodes_group(cpumask_first(cpu_map), cpu_map, &sg, - tmpmask); - init_numa_sched_groups_power(sg); - } -#endif - - /* Attach the domains */ - for_each_cpu(i, cpu_map) { - struct sched_domain *sd; -#ifdef CONFIG_SCHED_SMT - sd = &per_cpu(cpu_domains, i).sd; -#elif defined(CONFIG_SCHED_MC) - sd = &per_cpu(core_domains, i).sd; -#else - sd = &per_cpu(phys_domains, i).sd; -#endif - cpu_attach_domain(sd, rd, i); - } - - err = 0; - -free_tmpmask: - free_cpumask_var(tmpmask); -free_send_covered: - free_cpumask_var(send_covered); -free_this_core_map: - free_cpumask_var(this_core_map); -free_this_sibling_map: - free_cpumask_var(this_sibling_map); -free_nodemask: - free_cpumask_var(nodemask); -free_notcovered: -#ifdef CONFIG_NUMA - free_cpumask_var(notcovered); -free_covered: - free_cpumask_var(covered); -free_domainspan: - free_cpumask_var(domainspan); -out: -#endif - return err; - -free_sched_groups: -#ifdef CONFIG_NUMA - kfree(sched_group_nodes); -#endif - goto free_tmpmask; - -#ifdef CONFIG_NUMA -error: - free_sched_groups(cpu_map, tmpmask); - free_rootdomain(rd); - goto free_tmpmask; -#endif -} - -static int build_sched_domains(const struct cpumask *cpu_map) -{ - return __build_sched_domains(cpu_map, NULL); -} - -static struct cpumask *doms_cur; /* current sched domains */ -static int ndoms_cur; /* number of sched domains in 'doms_cur' */ -static struct sched_domain_attr *dattr_cur; - /* attribues of custom domains in 'doms_cur' */ - -/* - * Special case: If a kmalloc of a doms_cur partition (array of - * cpumask) fails, then fallback to a single sched domain, - * as determined by the single cpumask fallback_doms. - */ -static cpumask_var_t fallback_doms; - -/* - * arch_update_cpu_topology lets virtualized architectures update the - * cpu core maps. It is supposed to return 1 if the topology changed - * or 0 if it stayed the same. - */ -int __attribute__((weak)) arch_update_cpu_topology(void) -{ - return 0; -} - -/* - * Set up scheduler domains and groups. Callers must hold the hotplug lock. - * For now this just excludes isolated cpus, but could be used to - * exclude other special cases in the future. - */ -static int arch_init_sched_domains(const struct cpumask *cpu_map) -{ - int err; - - arch_update_cpu_topology(); - ndoms_cur = 1; - doms_cur = kmalloc(cpumask_size(), GFP_KERNEL); - if (!doms_cur) - doms_cur = fallback_doms; - cpumask_andnot(doms_cur, cpu_map, cpu_isolated_map); - dattr_cur = NULL; - err = build_sched_domains(doms_cur); - register_sched_domain_sysctl(); - - return err; -} - -static void arch_destroy_sched_domains(const struct cpumask *cpu_map, - struct cpumask *tmpmask) -{ - free_sched_groups(cpu_map, tmpmask); -} - -/* - * Detach sched domains from a group of cpus specified in cpu_map - * These cpus will now be attached to the NULL domain - */ -static void detach_destroy_domains(const struct cpumask *cpu_map) -{ - /* Save because hotplug lock held. */ - static DECLARE_BITMAP(tmpmask, CONFIG_NR_CPUS); - int i; - - for_each_cpu(i, cpu_map) - cpu_attach_domain(NULL, &def_root_domain, i); - synchronize_sched(); - arch_destroy_sched_domains(cpu_map, to_cpumask(tmpmask)); -} - -/* handle null as "default" */ -static int dattrs_equal(struct sched_domain_attr *cur, int idx_cur, - struct sched_domain_attr *new, int idx_new) -{ - struct sched_domain_attr tmp; - - /* fast path */ - if (!new && !cur) - return 1; - - tmp = SD_ATTR_INIT; - return !memcmp(cur ? (cur + idx_cur) : &tmp, - new ? (new + idx_new) : &tmp, - sizeof(struct sched_domain_attr)); -} - -/* - * Partition sched domains as specified by the 'ndoms_new' - * cpumasks in the array doms_new[] of cpumasks. This compares - * doms_new[] to the current sched domain partitioning, doms_cur[]. - * It destroys each deleted domain and builds each new domain. - * - * 'doms_new' is an array of cpumask's of length 'ndoms_new'. - * The masks don't intersect (don't overlap.) We should setup one - * sched domain for each mask. CPUs not in any of the cpumasks will - * not be load balanced. If the same cpumask appears both in the - * current 'doms_cur' domains and in the new 'doms_new', we can leave - * it as it is. - * - * The passed in 'doms_new' should be kmalloc'd. This routine takes - * ownership of it and will kfree it when done with it. If the caller - * failed the kmalloc call, then it can pass in doms_new == NULL && - * ndoms_new == 1, and partition_sched_domains() will fallback to - * the single partition 'fallback_doms', it also forces the domains - * to be rebuilt. - * - * If doms_new == NULL it will be replaced with cpu_online_mask. - * ndoms_new == 0 is a special case for destroying existing domains, - * and it will not create the default domain. - * - * Call with hotplug lock held - */ -/* FIXME: Change to struct cpumask *doms_new[] */ -void partition_sched_domains(int ndoms_new, struct cpumask *doms_new, - struct sched_domain_attr *dattr_new) -{ - int i, j, n; - int new_topology; - - mutex_lock(&sched_domains_mutex); - - /* always unregister in case we don't destroy any domains */ - unregister_sched_domain_sysctl(); - - /* Let architecture update cpu core mappings. */ - new_topology = arch_update_cpu_topology(); - - n = doms_new ? ndoms_new : 0; - - /* Destroy deleted domains */ - for (i = 0; i < ndoms_cur; i++) { - for (j = 0; j < n && !new_topology; j++) { - if (cpumask_equal(&doms_cur[i], &doms_new[j]) - && dattrs_equal(dattr_cur, i, dattr_new, j)) - goto match1; - } - /* no match - a current sched domain not in new doms_new[] */ - detach_destroy_domains(doms_cur + i); -match1: - ; - } - - if (doms_new == NULL) { - ndoms_cur = 0; - doms_new = fallback_doms; - cpumask_andnot(&doms_new[0], cpu_online_mask, cpu_isolated_map); - WARN_ON_ONCE(dattr_new); - } - - /* Build new domains */ - for (i = 0; i < ndoms_new; i++) { - for (j = 0; j < ndoms_cur && !new_topology; j++) { - if (cpumask_equal(&doms_new[i], &doms_cur[j]) - && dattrs_equal(dattr_new, i, dattr_cur, j)) - goto match2; - } - /* no match - add a new doms_new */ - __build_sched_domains(doms_new + i, - dattr_new ? dattr_new + i : NULL); -match2: - ; - } - - /* Remember the new sched domains */ - if (doms_cur != fallback_doms) - kfree(doms_cur); - kfree(dattr_cur); /* kfree(NULL) is safe */ - doms_cur = doms_new; - dattr_cur = dattr_new; - ndoms_cur = ndoms_new; - - register_sched_domain_sysctl(); - - mutex_unlock(&sched_domains_mutex); -} - -#if defined(CONFIG_SCHED_MC) || defined(CONFIG_SCHED_SMT) -static void arch_reinit_sched_domains(void) -{ - get_online_cpus(); - - /* Destroy domains first to force the rebuild */ - partition_sched_domains(0, NULL, NULL); - - rebuild_sched_domains(); - put_online_cpus(); -} - -static ssize_t sched_power_savings_store(const char *buf, size_t count, int smt) -{ - unsigned int level = 0; - - if (sscanf(buf, "%u", &level) != 1) - return -EINVAL; - - /* - * level is always be positive so don't check for - * level < POWERSAVINGS_BALANCE_NONE which is 0 - * What happens on 0 or 1 byte write, - * need to check for count as well? - */ - - if (level >= MAX_POWERSAVINGS_BALANCE_LEVELS) - return -EINVAL; - - if (smt) - sched_smt_power_savings = level; - else - sched_mc_power_savings = level; - - arch_reinit_sched_domains(); - - return count; -} - -#ifdef CONFIG_SCHED_MC -static ssize_t sched_mc_power_savings_show(struct sysdev_class *class, - char *page) -{ - return sprintf(page, "%u\n", sched_mc_power_savings); -} -static ssize_t sched_mc_power_savings_store(struct sysdev_class *class, - const char *buf, size_t count) -{ - return sched_power_savings_store(buf, count, 0); -} -static SYSDEV_CLASS_ATTR(sched_mc_power_savings, 0644, - sched_mc_power_savings_show, - sched_mc_power_savings_store); -#endif - -#ifdef CONFIG_SCHED_SMT -static ssize_t sched_smt_power_savings_show(struct sysdev_class *dev, - char *page) -{ - return sprintf(page, "%u\n", sched_smt_power_savings); -} -static ssize_t sched_smt_power_savings_store(struct sysdev_class *dev, - const char *buf, size_t count) -{ - return sched_power_savings_store(buf, count, 1); -} -static SYSDEV_CLASS_ATTR(sched_smt_power_savings, 0644, - sched_smt_power_savings_show, - sched_smt_power_savings_store); -#endif - -int __init sched_create_sysfs_power_savings_entries(struct sysdev_class *cls) -{ - int err = 0; - -#ifdef CONFIG_SCHED_SMT - if (smt_capable()) - err = sysfs_create_file(&cls->kset.kobj, - &attr_sched_smt_power_savings.attr); -#endif -#ifdef CONFIG_SCHED_MC - if (!err && mc_capable()) - err = sysfs_create_file(&cls->kset.kobj, - &attr_sched_mc_power_savings.attr); -#endif - return err; -} -#endif /* CONFIG_SCHED_MC || CONFIG_SCHED_SMT */ - -#ifndef CONFIG_CPUSETS -/* - * Add online and remove offline CPUs from the scheduler domains. - * When cpusets are enabled they take over this function. - */ -static int update_sched_domains(struct notifier_block *nfb, - unsigned long action, void *hcpu) -{ - switch (action) { - case CPU_ONLINE: - case CPU_ONLINE_FROZEN: - case CPU_DEAD: - case CPU_DEAD_FROZEN: - partition_sched_domains(1, NULL, NULL); - return NOTIFY_OK; - - default: - return NOTIFY_DONE; - } -} -#endif - -static int update_runtime(struct notifier_block *nfb, - unsigned long action, void *hcpu) -{ - int cpu = (int)(long)hcpu; - - switch (action) { - case CPU_DOWN_PREPARE: - case CPU_DOWN_PREPARE_FROZEN: - disable_runtime(cpu_rq(cpu)); - return NOTIFY_OK; - - case CPU_DOWN_FAILED: - case CPU_DOWN_FAILED_FROZEN: - case CPU_ONLINE: - case CPU_ONLINE_FROZEN: - enable_runtime(cpu_rq(cpu)); - return NOTIFY_OK; - - default: - return NOTIFY_DONE; - } -} - -void __init sched_init_smp(void) -{ - cpumask_var_t non_isolated_cpus; - - alloc_cpumask_var(&non_isolated_cpus, GFP_KERNEL); - -#if defined(CONFIG_NUMA) - sched_group_nodes_bycpu = kzalloc(nr_cpu_ids * sizeof(void **), - GFP_KERNEL); - BUG_ON(sched_group_nodes_bycpu == NULL); -#endif - get_online_cpus(); - mutex_lock(&sched_domains_mutex); - arch_init_sched_domains(cpu_online_mask); - cpumask_andnot(non_isolated_cpus, cpu_possible_mask, cpu_isolated_map); - if (cpumask_empty(non_isolated_cpus)) - cpumask_set_cpu(smp_processor_id(), non_isolated_cpus); - mutex_unlock(&sched_domains_mutex); - put_online_cpus(); - -#ifndef CONFIG_CPUSETS - /* XXX: Theoretical race here - CPU may be hotplugged now */ - hotcpu_notifier(update_sched_domains, 0); -#endif - - /* RT runtime code needs to handle some hotplug events */ - hotcpu_notifier(update_runtime, 0); - - init_hrtick(); - - /* Move init over to a non-isolated CPU */ - if (set_cpus_allowed_ptr(current, non_isolated_cpus) < 0) - BUG(); - sched_init_granularity(); - free_cpumask_var(non_isolated_cpus); - - alloc_cpumask_var(&fallback_doms, GFP_KERNEL); - init_sched_rt_class(); -} -#else -void __init sched_init_smp(void) -{ - sched_init_granularity(); -} -#endif /* CONFIG_SMP */ - -int in_sched_functions(unsigned long addr) -{ - return in_lock_functions(addr) || - (addr >= (unsigned long)__sched_text_start - && addr < (unsigned long)__sched_text_end); -} - -static void init_cfs_rq(struct cfs_rq *cfs_rq, struct rq *rq) -{ - cfs_rq->tasks_timeline = RB_ROOT; - INIT_LIST_HEAD(&cfs_rq->tasks); -#ifdef CONFIG_FAIR_GROUP_SCHED - cfs_rq->rq = rq; -#endif - cfs_rq->min_vruntime = (u64)(-(1LL << 20)); -} - -static void init_rt_rq(struct rt_rq *rt_rq, struct rq *rq) -{ - struct rt_prio_array *array; - int i; - - array = &rt_rq->active; - for (i = 0; i < MAX_RT_PRIO; i++) { - INIT_LIST_HEAD(array->queue + i); - __clear_bit(i, array->bitmap); - } - /* delimiter for bitsearch: */ - __set_bit(MAX_RT_PRIO, array->bitmap); - -#if defined CONFIG_SMP || defined CONFIG_RT_GROUP_SCHED - rt_rq->highest_prio.curr = MAX_RT_PRIO; -#ifdef CONFIG_SMP - rt_rq->highest_prio.next = MAX_RT_PRIO; -#endif -#endif -#ifdef CONFIG_SMP - rt_rq->rt_nr_migratory = 0; - rt_rq->overloaded = 0; - plist_head_init(&rq->rt.pushable_tasks, &rq->lock); -#endif - - rt_rq->rt_time = 0; - rt_rq->rt_throttled = 0; - rt_rq->rt_runtime = 0; - spin_lock_init(&rt_rq->rt_runtime_lock); - -#ifdef CONFIG_RT_GROUP_SCHED - rt_rq->rt_nr_boosted = 0; - rt_rq->rq = rq; -#endif -} - -#ifdef CONFIG_FAIR_GROUP_SCHED -static void init_tg_cfs_entry(struct task_group *tg, struct cfs_rq *cfs_rq, - struct sched_entity *se, int cpu, int add, - struct sched_entity *parent) -{ - struct rq *rq = cpu_rq(cpu); - tg->cfs_rq[cpu] = cfs_rq; - init_cfs_rq(cfs_rq, rq); - cfs_rq->tg = tg; - if (add) - list_add(&cfs_rq->leaf_cfs_rq_list, &rq->leaf_cfs_rq_list); - - tg->se[cpu] = se; - /* se could be NULL for init_task_group */ - if (!se) - return; - - if (!parent) - se->cfs_rq = &rq->cfs; - else - se->cfs_rq = parent->my_q; - - se->my_q = cfs_rq; - se->load.weight = tg->shares; - se->load.inv_weight = 0; - se->parent = parent; -} -#endif - -#ifdef CONFIG_RT_GROUP_SCHED -static void init_tg_rt_entry(struct task_group *tg, struct rt_rq *rt_rq, - struct sched_rt_entity *rt_se, int cpu, int add, - struct sched_rt_entity *parent) -{ - struct rq *rq = cpu_rq(cpu); - - tg->rt_rq[cpu] = rt_rq; - init_rt_rq(rt_rq, rq); - rt_rq->tg = tg; - rt_rq->rt_se = rt_se; - rt_rq->rt_runtime = tg->rt_bandwidth.rt_runtime; - if (add) - list_add(&rt_rq->leaf_rt_rq_list, &rq->leaf_rt_rq_list); - - tg->rt_se[cpu] = rt_se; - if (!rt_se) - return; - - if (!parent) - rt_se->rt_rq = &rq->rt; - else - rt_se->rt_rq = parent->my_q; - - rt_se->my_q = rt_rq; - rt_se->parent = parent; - INIT_LIST_HEAD(&rt_se->run_list); -} -#endif - -void __init sched_init(void) -{ - int i, j; - unsigned long alloc_size = 0, ptr; - -#ifdef CONFIG_FAIR_GROUP_SCHED - alloc_size += 2 * nr_cpu_ids * sizeof(void **); -#endif -#ifdef CONFIG_RT_GROUP_SCHED - alloc_size += 2 * nr_cpu_ids * sizeof(void **); -#endif -#ifdef CONFIG_USER_SCHED - alloc_size *= 2; -#endif -#ifdef CONFIG_CPUMASK_OFFSTACK - alloc_size += num_possible_cpus() * cpumask_size(); -#endif - /* - * As sched_init() is called before page_alloc is setup, - * we use alloc_bootmem(). - */ - if (alloc_size) { - ptr = (unsigned long)alloc_bootmem(alloc_size); - -#ifdef CONFIG_FAIR_GROUP_SCHED - init_task_group.se = (struct sched_entity **)ptr; - ptr += nr_cpu_ids * sizeof(void **); - - init_task_group.cfs_rq = (struct cfs_rq **)ptr; - ptr += nr_cpu_ids * sizeof(void **); - -#ifdef CONFIG_USER_SCHED - root_task_group.se = (struct sched_entity **)ptr; - ptr += nr_cpu_ids * sizeof(void **); - - root_task_group.cfs_rq = (struct cfs_rq **)ptr; - ptr += nr_cpu_ids * sizeof(void **); -#endif /* CONFIG_USER_SCHED */ -#endif /* CONFIG_FAIR_GROUP_SCHED */ -#ifdef CONFIG_RT_GROUP_SCHED - init_task_group.rt_se = (struct sched_rt_entity **)ptr; - ptr += nr_cpu_ids * sizeof(void **); - - init_task_group.rt_rq = (struct rt_rq **)ptr; - ptr += nr_cpu_ids * sizeof(void **); - -#ifdef CONFIG_USER_SCHED - root_task_group.rt_se = (struct sched_rt_entity **)ptr; - ptr += nr_cpu_ids * sizeof(void **); - - root_task_group.rt_rq = (struct rt_rq **)ptr; - ptr += nr_cpu_ids * sizeof(void **); -#endif /* CONFIG_USER_SCHED */ -#endif /* CONFIG_RT_GROUP_SCHED */ -#ifdef CONFIG_CPUMASK_OFFSTACK - for_each_possible_cpu(i) { - per_cpu(load_balance_tmpmask, i) = (void *)ptr; - ptr += cpumask_size(); - } -#endif /* CONFIG_CPUMASK_OFFSTACK */ - } - -#ifdef CONFIG_SMP - init_defrootdomain(); -#endif - - init_rt_bandwidth(&def_rt_bandwidth, - global_rt_period(), global_rt_runtime()); - -#ifdef CONFIG_RT_GROUP_SCHED - init_rt_bandwidth(&init_task_group.rt_bandwidth, - global_rt_period(), global_rt_runtime()); -#ifdef CONFIG_USER_SCHED - init_rt_bandwidth(&root_task_group.rt_bandwidth, - global_rt_period(), RUNTIME_INF); -#endif /* CONFIG_USER_SCHED */ -#endif /* CONFIG_RT_GROUP_SCHED */ - -#ifdef CONFIG_GROUP_SCHED - list_add(&init_task_group.list, &task_groups); - INIT_LIST_HEAD(&init_task_group.children); - -#ifdef CONFIG_USER_SCHED - INIT_LIST_HEAD(&root_task_group.children); - init_task_group.parent = &root_task_group; - list_add(&init_task_group.siblings, &root_task_group.children); -#endif /* CONFIG_USER_SCHED */ -#endif /* CONFIG_GROUP_SCHED */ - - for_each_possible_cpu(i) { - struct rq *rq; - - rq = cpu_rq(i); - spin_lock_init(&rq->lock); - rq->nr_running = 0; - init_cfs_rq(&rq->cfs, rq); - init_rt_rq(&rq->rt, rq); -#ifdef CONFIG_FAIR_GROUP_SCHED - init_task_group.shares = init_task_group_load; - INIT_LIST_HEAD(&rq->leaf_cfs_rq_list); -#ifdef CONFIG_CGROUP_SCHED - /* - * How much cpu bandwidth does init_task_group get? - * - * In case of task-groups formed thr' the cgroup filesystem, it - * gets 100% of the cpu resources in the system. This overall - * system cpu resource is divided among the tasks of - * init_task_group and its child task-groups in a fair manner, - * based on each entity's (task or task-group's) weight - * (se->load.weight). - * - * In other words, if init_task_group has 10 tasks of weight - * 1024) and two child groups A0 and A1 (of weight 1024 each), - * then A0's share of the cpu resource is: - * - * A0's bandwidth = 1024 / (10*1024 + 1024 + 1024) = 8.33% - * - * We achieve this by letting init_task_group's tasks sit - * directly in rq->cfs (i.e init_task_group->se[] = NULL). - */ - init_tg_cfs_entry(&init_task_group, &rq->cfs, NULL, i, 1, NULL); -#elif defined CONFIG_USER_SCHED - root_task_group.shares = NICE_0_LOAD; - init_tg_cfs_entry(&root_task_group, &rq->cfs, NULL, i, 0, NULL); - /* - * In case of task-groups formed thr' the user id of tasks, - * init_task_group represents tasks belonging to root user. - * Hence it forms a sibling of all subsequent groups formed. - * In this case, init_task_group gets only a fraction of overall - * system cpu resource, based on the weight assigned to root - * user's cpu share (INIT_TASK_GROUP_LOAD). This is accomplished - * by letting tasks of init_task_group sit in a separate cfs_rq - * (init_cfs_rq) and having one entity represent this group of - * tasks in rq->cfs (i.e init_task_group->se[] != NULL). - */ - init_tg_cfs_entry(&init_task_group, - &per_cpu(init_cfs_rq, i), - &per_cpu(init_sched_entity, i), i, 1, - root_task_group.se[i]); - -#endif -#endif /* CONFIG_FAIR_GROUP_SCHED */ - - rq->rt.rt_runtime = def_rt_bandwidth.rt_runtime; -#ifdef CONFIG_RT_GROUP_SCHED - INIT_LIST_HEAD(&rq->leaf_rt_rq_list); -#ifdef CONFIG_CGROUP_SCHED - init_tg_rt_entry(&init_task_group, &rq->rt, NULL, i, 1, NULL); -#elif defined CONFIG_USER_SCHED - init_tg_rt_entry(&root_task_group, &rq->rt, NULL, i, 0, NULL); - init_tg_rt_entry(&init_task_group, - &per_cpu(init_rt_rq, i), - &per_cpu(init_sched_rt_entity, i), i, 1, - root_task_group.rt_se[i]); -#endif -#endif - - for (j = 0; j < CPU_LOAD_IDX_MAX; j++) - rq->cpu_load[j] = 0; -#ifdef CONFIG_SMP - rq->sd = NULL; - rq->rd = NULL; - rq->active_balance = 0; - rq->next_balance = jiffies; - rq->push_cpu = 0; - rq->cpu = i; - rq->online = 0; - rq->migration_thread = NULL; - INIT_LIST_HEAD(&rq->migration_queue); - rq_attach_root(rq, &def_root_domain); -#endif - init_rq_hrtick(rq); - atomic_set(&rq->nr_iowait, 0); - } - - set_load_weight(&init_task); - -#ifdef CONFIG_PREEMPT_NOTIFIERS - INIT_HLIST_HEAD(&init_task.preempt_notifiers); -#endif - -#ifdef CONFIG_SMP - open_softirq(SCHED_SOFTIRQ, run_rebalance_domains); -#endif - -#ifdef CONFIG_RT_MUTEXES - plist_head_init(&init_task.pi_waiters, &init_task.pi_lock); -#endif - - /* - * The boot idle thread does lazy MMU switching as well: - */ - atomic_inc(&init_mm.mm_count); - enter_lazy_tlb(&init_mm, current); - - /* - * Make us the idle thread. Technically, schedule() should not be - * called from this thread, however somewhere below it might be, - * but because we are the idle thread, we just pick up running again - * when this runqueue becomes "idle". - */ - init_idle(current, smp_processor_id()); - /* - * During early bootup we pretend to be a normal task: - */ - current->sched_class = &fair_sched_class; - - /* Allocate the nohz_cpu_mask if CONFIG_CPUMASK_OFFSTACK */ - alloc_bootmem_cpumask_var(&nohz_cpu_mask); -#ifdef CONFIG_SMP -#ifdef CONFIG_NO_HZ - alloc_bootmem_cpumask_var(&nohz.cpu_mask); -#endif - alloc_bootmem_cpumask_var(&cpu_isolated_map); -#endif /* SMP */ - - scheduler_running = 1; -} - -#ifdef CONFIG_DEBUG_SPINLOCK_SLEEP -void __might_sleep(char *file, int line) -{ -#ifdef in_atomic - static unsigned long prev_jiffy; /* ratelimiting */ - - if ((!in_atomic() && !irqs_disabled()) || - system_state != SYSTEM_RUNNING || oops_in_progress) - return; - if (time_before(jiffies, prev_jiffy + HZ) && prev_jiffy) - return; - prev_jiffy = jiffies; - - printk(KERN_ERR - "BUG: sleeping function called from invalid context at %s:%d\n", - file, line); - printk(KERN_ERR - "in_atomic(): %d, irqs_disabled(): %d, pid: %d, name: %s\n", - in_atomic(), irqs_disabled(), - current->pid, current->comm); - - debug_show_held_locks(current); - if (irqs_disabled()) - print_irqtrace_events(current); - dump_stack(); -#endif -} -EXPORT_SYMBOL(__might_sleep); -#endif - -#ifdef CONFIG_MAGIC_SYSRQ -static void normalize_task(struct rq *rq, struct task_struct *p) -{ - int on_rq; - - update_rq_clock(rq); - on_rq = p->se.on_rq; - if (on_rq) - deactivate_task(rq, p, 0); - __setscheduler(rq, p, SCHED_NORMAL, 0); - if (on_rq) { - activate_task(rq, p, 0); - resched_task(rq->curr); - } -} - -void normalize_rt_tasks(void) -{ - struct task_struct *g, *p; - unsigned long flags; - struct rq *rq; - - read_lock_irqsave(&tasklist_lock, flags); - do_each_thread(g, p) { - /* - * Only normalize user tasks: - */ - if (!p->mm) - continue; - - p->se.exec_start = 0; -#ifdef CONFIG_SCHEDSTATS - p->se.wait_start = 0; - p->se.sleep_start = 0; - p->se.block_start = 0; -#endif - - if (!rt_task(p)) { - /* - * Renice negative nice level userspace - * tasks back to 0: - */ - if (TASK_NICE(p) < 0 && p->mm) - set_user_nice(p, 0); - continue; - } - - spin_lock(&p->pi_lock); - rq = __task_rq_lock(p); - - normalize_task(rq, p); - - __task_rq_unlock(rq); - spin_unlock(&p->pi_lock); - } while_each_thread(g, p); - - read_unlock_irqrestore(&tasklist_lock, flags); -} - -#endif /* CONFIG_MAGIC_SYSRQ */ - -#ifdef CONFIG_IA64 -/* - * These functions are only useful for the IA64 MCA handling. - * - * They can only be called when the whole system has been - * stopped - every CPU needs to be quiescent, and no scheduling - * activity can take place. Using them for anything else would - * be a serious bug, and as a result, they aren't even visible - * under any other configuration. - */ - -/** - * curr_task - return the current task for a given cpu. - * @cpu: the processor in question. - * - * ONLY VALID WHEN THE WHOLE SYSTEM IS STOPPED! - */ -struct task_struct *curr_task(int cpu) -{ - return cpu_curr(cpu); -} - -/** - * set_curr_task - set the current task for a given cpu. - * @cpu: the processor in question. - * @p: the task pointer to set. - * - * Description: This function must only be used when non-maskable interrupts - * are serviced on a separate stack. It allows the architecture to switch the - * notion of the current task on a cpu in a non-blocking manner. This function - * must be called with all CPU's synchronized, and interrupts disabled, the - * and caller must save the original value of the current task (see - * curr_task() above) and restore that value before reenabling interrupts and - * re-starting the system. - * - * ONLY VALID WHEN THE WHOLE SYSTEM IS STOPPED! - */ -void set_curr_task(int cpu, struct task_struct *p) -{ - cpu_curr(cpu) = p; -} - -#endif - -#ifdef CONFIG_FAIR_GROUP_SCHED -static void free_fair_sched_group(struct task_group *tg) -{ - int i; - - for_each_possible_cpu(i) { - if (tg->cfs_rq) - kfree(tg->cfs_rq[i]); - if (tg->se) - kfree(tg->se[i]); - } - - kfree(tg->cfs_rq); - kfree(tg->se); -} - -static -int alloc_fair_sched_group(struct task_group *tg, struct task_group *parent) -{ - struct cfs_rq *cfs_rq; - struct sched_entity *se; - struct rq *rq; - int i; - - tg->cfs_rq = kzalloc(sizeof(cfs_rq) * nr_cpu_ids, GFP_KERNEL); - if (!tg->cfs_rq) - goto err; - tg->se = kzalloc(sizeof(se) * nr_cpu_ids, GFP_KERNEL); - if (!tg->se) - goto err; - - tg->shares = NICE_0_LOAD; - - for_each_possible_cpu(i) { - rq = cpu_rq(i); - - cfs_rq = kzalloc_node(sizeof(struct cfs_rq), - GFP_KERNEL, cpu_to_node(i)); - if (!cfs_rq) - goto err; - - se = kzalloc_node(sizeof(struct sched_entity), - GFP_KERNEL, cpu_to_node(i)); - if (!se) - goto err; - - init_tg_cfs_entry(tg, cfs_rq, se, i, 0, parent->se[i]); - } - - return 1; - - err: - return 0; -} - -static inline void register_fair_sched_group(struct task_group *tg, int cpu) -{ - list_add_rcu(&tg->cfs_rq[cpu]->leaf_cfs_rq_list, - &cpu_rq(cpu)->leaf_cfs_rq_list); -} - -static inline void unregister_fair_sched_group(struct task_group *tg, int cpu) -{ - list_del_rcu(&tg->cfs_rq[cpu]->leaf_cfs_rq_list); -} -#else /* !CONFG_FAIR_GROUP_SCHED */ -static inline void free_fair_sched_group(struct task_group *tg) -{ -} - -static inline -int alloc_fair_sched_group(struct task_group *tg, struct task_group *parent) -{ - return 1; -} - -static inline void register_fair_sched_group(struct task_group *tg, int cpu) -{ -} - -static inline void unregister_fair_sched_group(struct task_group *tg, int cpu) -{ -} -#endif /* CONFIG_FAIR_GROUP_SCHED */ - -#ifdef CONFIG_RT_GROUP_SCHED -static void free_rt_sched_group(struct task_group *tg) -{ - int i; - - destroy_rt_bandwidth(&tg->rt_bandwidth); - - for_each_possible_cpu(i) { - if (tg->rt_rq) - kfree(tg->rt_rq[i]); - if (tg->rt_se) - kfree(tg->rt_se[i]); - } - - kfree(tg->rt_rq); - kfree(tg->rt_se); -} - -static -int alloc_rt_sched_group(struct task_group *tg, struct task_group *parent) -{ - struct rt_rq *rt_rq; - struct sched_rt_entity *rt_se; - struct rq *rq; - int i; - - tg->rt_rq = kzalloc(sizeof(rt_rq) * nr_cpu_ids, GFP_KERNEL); - if (!tg->rt_rq) - goto err; - tg->rt_se = kzalloc(sizeof(rt_se) * nr_cpu_ids, GFP_KERNEL); - if (!tg->rt_se) - goto err; - - init_rt_bandwidth(&tg->rt_bandwidth, - ktime_to_ns(def_rt_bandwidth.rt_period), 0); - - for_each_possible_cpu(i) { - rq = cpu_rq(i); - - rt_rq = kzalloc_node(sizeof(struct rt_rq), - GFP_KERNEL, cpu_to_node(i)); - if (!rt_rq) - goto err; - - rt_se = kzalloc_node(sizeof(struct sched_rt_entity), - GFP_KERNEL, cpu_to_node(i)); - if (!rt_se) - goto err; - - init_tg_rt_entry(tg, rt_rq, rt_se, i, 0, parent->rt_se[i]); - } - - return 1; - - err: - return 0; -} - -static inline void register_rt_sched_group(struct task_group *tg, int cpu) -{ - list_add_rcu(&tg->rt_rq[cpu]->leaf_rt_rq_list, - &cpu_rq(cpu)->leaf_rt_rq_list); -} - -static inline void unregister_rt_sched_group(struct task_group *tg, int cpu) -{ - list_del_rcu(&tg->rt_rq[cpu]->leaf_rt_rq_list); -} -#else /* !CONFIG_RT_GROUP_SCHED */ -static inline void free_rt_sched_group(struct task_group *tg) -{ -} - -static inline -int alloc_rt_sched_group(struct task_group *tg, struct task_group *parent) -{ - return 1; -} - -static inline void register_rt_sched_group(struct task_group *tg, int cpu) -{ -} - -static inline void unregister_rt_sched_group(struct task_group *tg, int cpu) -{ -} -#endif /* CONFIG_RT_GROUP_SCHED */ - -#ifdef CONFIG_GROUP_SCHED -static void free_sched_group(struct task_group *tg) -{ - free_fair_sched_group(tg); - free_rt_sched_group(tg); - kfree(tg); -} - -/* allocate runqueue etc for a new task group */ -struct task_group *sched_create_group(struct task_group *parent) -{ - struct task_group *tg; - unsigned long flags; - int i; - - tg = kzalloc(sizeof(*tg), GFP_KERNEL); - if (!tg) - return ERR_PTR(-ENOMEM); - - if (!alloc_fair_sched_group(tg, parent)) - goto err; - - if (!alloc_rt_sched_group(tg, parent)) - goto err; - - spin_lock_irqsave(&task_group_lock, flags); - for_each_possible_cpu(i) { - register_fair_sched_group(tg, i); - register_rt_sched_group(tg, i); - } - list_add_rcu(&tg->list, &task_groups); - - WARN_ON(!parent); /* root should already exist */ - - tg->parent = parent; - INIT_LIST_HEAD(&tg->children); - list_add_rcu(&tg->siblings, &parent->children); - spin_unlock_irqrestore(&task_group_lock, flags); - - return tg; - -err: - free_sched_group(tg); - return ERR_PTR(-ENOMEM); -} - -/* rcu callback to free various structures associated with a task group */ -static void free_sched_group_rcu(struct rcu_head *rhp) -{ - /* now it should be safe to free those cfs_rqs */ - free_sched_group(container_of(rhp, struct task_group, rcu)); -} - -/* Destroy runqueue etc associated with a task group */ -void sched_destroy_group(struct task_group *tg) -{ - unsigned long flags; - int i; - - spin_lock_irqsave(&task_group_lock, flags); - for_each_possible_cpu(i) { - unregister_fair_sched_group(tg, i); - unregister_rt_sched_group(tg, i); - } - list_del_rcu(&tg->list); - list_del_rcu(&tg->siblings); - spin_unlock_irqrestore(&task_group_lock, flags); - - /* wait for possible concurrent references to cfs_rqs complete */ - call_rcu(&tg->rcu, free_sched_group_rcu); -} - -/* change task's runqueue when it moves between groups. - * The caller of this function should have put the task in its new group - * by now. This function just updates tsk->se.cfs_rq and tsk->se.parent to - * reflect its new group. - */ -void sched_move_task(struct task_struct *tsk) -{ - int on_rq, running; - unsigned long flags; - struct rq *rq; - - rq = task_rq_lock(tsk, &flags); - - update_rq_clock(rq); - - running = task_current(rq, tsk); - on_rq = tsk->se.on_rq; - - if (on_rq) - dequeue_task(rq, tsk, 0); - if (unlikely(running)) - tsk->sched_class->put_prev_task(rq, tsk); - - set_task_rq(tsk, task_cpu(tsk)); - -#ifdef CONFIG_FAIR_GROUP_SCHED - if (tsk->sched_class->moved_group) - tsk->sched_class->moved_group(tsk); -#endif - - if (unlikely(running)) - tsk->sched_class->set_curr_task(rq); - if (on_rq) - enqueue_task(rq, tsk, 0); - - task_rq_unlock(rq, &flags); -} -#endif /* CONFIG_GROUP_SCHED */ - -#ifdef CONFIG_FAIR_GROUP_SCHED -static void __set_se_shares(struct sched_entity *se, unsigned long shares) -{ - struct cfs_rq *cfs_rq = se->cfs_rq; - int on_rq; - - on_rq = se->on_rq; - if (on_rq) - dequeue_entity(cfs_rq, se, 0); - - se->load.weight = shares; - se->load.inv_weight = 0; - - if (on_rq) - enqueue_entity(cfs_rq, se, 0); -} - -static void set_se_shares(struct sched_entity *se, unsigned long shares) -{ - struct cfs_rq *cfs_rq = se->cfs_rq; - struct rq *rq = cfs_rq->rq; - unsigned long flags; - - spin_lock_irqsave(&rq->lock, flags); - __set_se_shares(se, shares); - spin_unlock_irqrestore(&rq->lock, flags); -} - -static DEFINE_MUTEX(shares_mutex); - -int sched_group_set_shares(struct task_group *tg, unsigned long shares) -{ - int i; - unsigned long flags; - - /* - * We can't change the weight of the root cgroup. - */ - if (!tg->se[0]) - return -EINVAL; - - if (shares < MIN_SHARES) - shares = MIN_SHARES; - else if (shares > MAX_SHARES) - shares = MAX_SHARES; - - mutex_lock(&shares_mutex); - if (tg->shares == shares) - goto done; - - spin_lock_irqsave(&task_group_lock, flags); - for_each_possible_cpu(i) - unregister_fair_sched_group(tg, i); - list_del_rcu(&tg->siblings); - spin_unlock_irqrestore(&task_group_lock, flags); - - /* wait for any ongoing reference to this group to finish */ - synchronize_sched(); - - /* - * Now we are free to modify the group's share on each cpu - * w/o tripping rebalance_share or load_balance_fair. - */ - tg->shares = shares; - for_each_possible_cpu(i) { - /* - * force a rebalance - */ - cfs_rq_set_shares(tg->cfs_rq[i], 0); - set_se_shares(tg->se[i], shares); - } - - /* - * Enable load balance activity on this group, by inserting it back on - * each cpu's rq->leaf_cfs_rq_list. - */ - spin_lock_irqsave(&task_group_lock, flags); - for_each_possible_cpu(i) - register_fair_sched_group(tg, i); - list_add_rcu(&tg->siblings, &tg->parent->children); - spin_unlock_irqrestore(&task_group_lock, flags); -done: - mutex_unlock(&shares_mutex); - return 0; -} - -unsigned long sched_group_shares(struct task_group *tg) -{ - return tg->shares; -} -#endif - -#ifdef CONFIG_RT_GROUP_SCHED -/* - * Ensure that the real time constraints are schedulable. - */ -static DEFINE_MUTEX(rt_constraints_mutex); - -static unsigned long to_ratio(u64 period, u64 runtime) -{ - if (runtime == RUNTIME_INF) - return 1ULL << 20; - - return div64_u64(runtime << 20, period); -} - -/* Must be called with tasklist_lock held */ -static inline int tg_has_rt_tasks(struct task_group *tg) -{ - struct task_struct *g, *p; - - do_each_thread(g, p) { - if (rt_task(p) && rt_rq_of_se(&p->rt)->tg == tg) - return 1; - } while_each_thread(g, p); - - return 0; -} - -struct rt_schedulable_data { - struct task_group *tg; - u64 rt_period; - u64 rt_runtime; -}; - -static int tg_schedulable(struct task_group *tg, void *data) -{ - struct rt_schedulable_data *d = data; - struct task_group *child; - unsigned long total, sum = 0; - u64 period, runtime; - - period = ktime_to_ns(tg->rt_bandwidth.rt_period); - runtime = tg->rt_bandwidth.rt_runtime; - - if (tg == d->tg) { - period = d->rt_period; - runtime = d->rt_runtime; - } - -#ifdef CONFIG_USER_SCHED - if (tg == &root_task_group) { - period = global_rt_period(); - runtime = global_rt_runtime(); - } -#endif - - /* - * Cannot have more runtime than the period. - */ - if (runtime > period && runtime != RUNTIME_INF) - return -EINVAL; - - /* - * Ensure we don't starve existing RT tasks. - */ - if (rt_bandwidth_enabled() && !runtime && tg_has_rt_tasks(tg)) - return -EBUSY; - - total = to_ratio(period, runtime); - - /* - * Nobody can have more than the global setting allows. - */ - if (total > to_ratio(global_rt_period(), global_rt_runtime())) - return -EINVAL; - - /* - * The sum of our children's runtime should not exceed our own. - */ - list_for_each_entry_rcu(child, &tg->children, siblings) { - period = ktime_to_ns(child->rt_bandwidth.rt_period); - runtime = child->rt_bandwidth.rt_runtime; - - if (child == d->tg) { - period = d->rt_period; - runtime = d->rt_runtime; - } - - sum += to_ratio(period, runtime); - } - - if (sum > total) - return -EINVAL; - - return 0; -} - -static int __rt_schedulable(struct task_group *tg, u64 period, u64 runtime) -{ - struct rt_schedulable_data data = { - .tg = tg, - .rt_period = period, - .rt_runtime = runtime, - }; - - return walk_tg_tree(tg_schedulable, tg_nop, &data); -} - -static int tg_set_bandwidth(struct task_group *tg, - u64 rt_period, u64 rt_runtime) -{ - int i, err = 0; - - mutex_lock(&rt_constraints_mutex); - read_lock(&tasklist_lock); - err = __rt_schedulable(tg, rt_period, rt_runtime); - if (err) - goto unlock; - - spin_lock_irq(&tg->rt_bandwidth.rt_runtime_lock); - tg->rt_bandwidth.rt_period = ns_to_ktime(rt_period); - tg->rt_bandwidth.rt_runtime = rt_runtime; - - for_each_possible_cpu(i) { - struct rt_rq *rt_rq = tg->rt_rq[i]; - - spin_lock(&rt_rq->rt_runtime_lock); - rt_rq->rt_runtime = rt_runtime; - spin_unlock(&rt_rq->rt_runtime_lock); - } - spin_unlock_irq(&tg->rt_bandwidth.rt_runtime_lock); - unlock: - read_unlock(&tasklist_lock); - mutex_unlock(&rt_constraints_mutex); - - return err; -} - -int sched_group_set_rt_runtime(struct task_group *tg, long rt_runtime_us) -{ - u64 rt_runtime, rt_period; - - rt_period = ktime_to_ns(tg->rt_bandwidth.rt_period); - rt_runtime = (u64)rt_runtime_us * NSEC_PER_USEC; - if (rt_runtime_us < 0) - rt_runtime = RUNTIME_INF; - - return tg_set_bandwidth(tg, rt_period, rt_runtime); -} - -long sched_group_rt_runtime(struct task_group *tg) -{ - u64 rt_runtime_us; - - if (tg->rt_bandwidth.rt_runtime == RUNTIME_INF) - return -1; - - rt_runtime_us = tg->rt_bandwidth.rt_runtime; - do_div(rt_runtime_us, NSEC_PER_USEC); - return rt_runtime_us; -} - -int sched_group_set_rt_period(struct task_group *tg, long rt_period_us) -{ - u64 rt_runtime, rt_period; - - rt_period = (u64)rt_period_us * NSEC_PER_USEC; - rt_runtime = tg->rt_bandwidth.rt_runtime; - - if (rt_period == 0) - return -EINVAL; - - return tg_set_bandwidth(tg, rt_period, rt_runtime); -} - -long sched_group_rt_period(struct task_group *tg) -{ - u64 rt_period_us; - - rt_period_us = ktime_to_ns(tg->rt_bandwidth.rt_period); - do_div(rt_period_us, NSEC_PER_USEC); - return rt_period_us; -} - -static int sched_rt_global_constraints(void) -{ - u64 runtime, period; - int ret = 0; - - if (sysctl_sched_rt_period <= 0) - return -EINVAL; - - runtime = global_rt_runtime(); - period = global_rt_period(); - - /* - * Sanity check on the sysctl variables. - */ - if (runtime > period && runtime != RUNTIME_INF) - return -EINVAL; - - mutex_lock(&rt_constraints_mutex); - read_lock(&tasklist_lock); - ret = __rt_schedulable(NULL, 0, 0); - read_unlock(&tasklist_lock); - mutex_unlock(&rt_constraints_mutex); - - return ret; -} - -int sched_rt_can_attach(struct task_group *tg, struct task_struct *tsk) -{ - /* Don't accept realtime tasks when there is no way for them to run */ - if (rt_task(tsk) && tg->rt_bandwidth.rt_runtime == 0) - return 0; - - return 1; -} - -#else /* !CONFIG_RT_GROUP_SCHED */ -static int sched_rt_global_constraints(void) -{ - unsigned long flags; - int i; - - if (sysctl_sched_rt_period <= 0) - return -EINVAL; - - spin_lock_irqsave(&def_rt_bandwidth.rt_runtime_lock, flags); - for_each_possible_cpu(i) { - struct rt_rq *rt_rq = &cpu_rq(i)->rt; - - spin_lock(&rt_rq->rt_runtime_lock); - rt_rq->rt_runtime = global_rt_runtime(); - spin_unlock(&rt_rq->rt_runtime_lock); - } - spin_unlock_irqrestore(&def_rt_bandwidth.rt_runtime_lock, flags); - - return 0; -} -#endif /* CONFIG_RT_GROUP_SCHED */ - -int sched_rt_handler(struct ctl_table *table, int write, - struct file *filp, void __user *buffer, size_t *lenp, - loff_t *ppos) -{ - int ret; - int old_period, old_runtime; - static DEFINE_MUTEX(mutex); - - mutex_lock(&mutex); - old_period = sysctl_sched_rt_period; - old_runtime = sysctl_sched_rt_runtime; - - ret = proc_dointvec(table, write, filp, buffer, lenp, ppos); - - if (!ret && write) { - ret = sched_rt_global_constraints(); - if (ret) { - sysctl_sched_rt_period = old_period; - sysctl_sched_rt_runtime = old_runtime; - } else { - def_rt_bandwidth.rt_runtime = global_rt_runtime(); - def_rt_bandwidth.rt_period = - ns_to_ktime(global_rt_period()); - } - } - mutex_unlock(&mutex); - - return ret; -} - -#ifdef CONFIG_CGROUP_SCHED - -/* return corresponding task_group object of a cgroup */ -static inline struct task_group *cgroup_tg(struct cgroup *cgrp) -{ - return container_of(cgroup_subsys_state(cgrp, cpu_cgroup_subsys_id), - struct task_group, css); -} - -static struct cgroup_subsys_state * -cpu_cgroup_create(struct cgroup_subsys *ss, struct cgroup *cgrp) -{ - struct task_group *tg, *parent; - - if (!cgrp->parent) { - /* This is early initialization for the top cgroup */ - return &init_task_group.css; - } - - parent = cgroup_tg(cgrp->parent); - tg = sched_create_group(parent); - if (IS_ERR(tg)) - return ERR_PTR(-ENOMEM); - - return &tg->css; -} - -static void -cpu_cgroup_destroy(struct cgroup_subsys *ss, struct cgroup *cgrp) -{ - struct task_group *tg = cgroup_tg(cgrp); - - sched_destroy_group(tg); -} - -static int -cpu_cgroup_can_attach(struct cgroup_subsys *ss, struct cgroup *cgrp, - struct task_struct *tsk) -{ -#ifdef CONFIG_RT_GROUP_SCHED - if (!sched_rt_can_attach(cgroup_tg(cgrp), tsk)) - return -EINVAL; -#else - /* We don't support RT-tasks being in separate groups */ - if (tsk->sched_class != &fair_sched_class) - return -EINVAL; -#endif - - return 0; -} - -static void -cpu_cgroup_attach(struct cgroup_subsys *ss, struct cgroup *cgrp, - struct cgroup *old_cont, struct task_struct *tsk) -{ - sched_move_task(tsk); -} - -#ifdef CONFIG_FAIR_GROUP_SCHED -static int cpu_shares_write_u64(struct cgroup *cgrp, struct cftype *cftype, - u64 shareval) -{ - return sched_group_set_shares(cgroup_tg(cgrp), shareval); -} - -static u64 cpu_shares_read_u64(struct cgroup *cgrp, struct cftype *cft) -{ - struct task_group *tg = cgroup_tg(cgrp); - - return (u64) tg->shares; -} -#endif /* CONFIG_FAIR_GROUP_SCHED */ - -#ifdef CONFIG_RT_GROUP_SCHED -static int cpu_rt_runtime_write(struct cgroup *cgrp, struct cftype *cft, - s64 val) -{ - return sched_group_set_rt_runtime(cgroup_tg(cgrp), val); -} - -static s64 cpu_rt_runtime_read(struct cgroup *cgrp, struct cftype *cft) -{ - return sched_group_rt_runtime(cgroup_tg(cgrp)); -} - -static int cpu_rt_period_write_uint(struct cgroup *cgrp, struct cftype *cftype, - u64 rt_period_us) -{ - return sched_group_set_rt_period(cgroup_tg(cgrp), rt_period_us); -} - -static u64 cpu_rt_period_read_uint(struct cgroup *cgrp, struct cftype *cft) -{ - return sched_group_rt_period(cgroup_tg(cgrp)); -} -#endif /* CONFIG_RT_GROUP_SCHED */ - -static struct cftype cpu_files[] = { -#ifdef CONFIG_FAIR_GROUP_SCHED - { - .name = "shares", - .read_u64 = cpu_shares_read_u64, - .write_u64 = cpu_shares_write_u64, - }, -#endif -#ifdef CONFIG_RT_GROUP_SCHED - { - .name = "rt_runtime_us", - .read_s64 = cpu_rt_runtime_read, - .write_s64 = cpu_rt_runtime_write, - }, - { - .name = "rt_period_us", - .read_u64 = cpu_rt_period_read_uint, - .write_u64 = cpu_rt_period_write_uint, - }, -#endif -}; - -static int cpu_cgroup_populate(struct cgroup_subsys *ss, struct cgroup *cont) -{ - return cgroup_add_files(cont, ss, cpu_files, ARRAY_SIZE(cpu_files)); -} - -struct cgroup_subsys cpu_cgroup_subsys = { - .name = "cpu", - .create = cpu_cgroup_create, - .destroy = cpu_cgroup_destroy, - .can_attach = cpu_cgroup_can_attach, - .attach = cpu_cgroup_attach, - .populate = cpu_cgroup_populate, - .subsys_id = cpu_cgroup_subsys_id, - .early_init = 1, -}; - -#endif /* CONFIG_CGROUP_SCHED */ - -#ifdef CONFIG_CGROUP_CPUACCT - -/* - * CPU accounting code for task groups. - * - * Based on the work by Paul Menage (menage@google.com) and Balbir Singh - * (balbir@in.ibm.com). - */ - -/* track cpu usage of a group of tasks and its child groups */ -struct cpuacct { - struct cgroup_subsys_state css; - /* cpuusage holds pointer to a u64-type object on every cpu */ - u64 *cpuusage; - struct percpu_counter cpustat[CPUACCT_STAT_NSTATS]; - struct cpuacct *parent; -}; - -struct cgroup_subsys cpuacct_subsys; - -/* return cpu accounting group corresponding to this container */ -static inline struct cpuacct *cgroup_ca(struct cgroup *cgrp) -{ - return container_of(cgroup_subsys_state(cgrp, cpuacct_subsys_id), - struct cpuacct, css); -} - -/* return cpu accounting group to which this task belongs */ -static inline struct cpuacct *task_ca(struct task_struct *tsk) -{ - return container_of(task_subsys_state(tsk, cpuacct_subsys_id), - struct cpuacct, css); -} - -/* create a new cpu accounting group */ -static struct cgroup_subsys_state *cpuacct_create( - struct cgroup_subsys *ss, struct cgroup *cgrp) -{ - struct cpuacct *ca = kzalloc(sizeof(*ca), GFP_KERNEL); - int i; - - if (!ca) - goto out; - - ca->cpuusage = alloc_percpu(u64); - if (!ca->cpuusage) - goto out_free_ca; - - for (i = 0; i < CPUACCT_STAT_NSTATS; i++) - if (percpu_counter_init(&ca->cpustat[i], 0)) - goto out_free_counters; - - if (cgrp->parent) - ca->parent = cgroup_ca(cgrp->parent); - - return &ca->css; - -out_free_counters: - while (--i >= 0) - percpu_counter_destroy(&ca->cpustat[i]); - free_percpu(ca->cpuusage); -out_free_ca: - kfree(ca); -out: - return ERR_PTR(-ENOMEM); -} - -/* destroy an existing cpu accounting group */ -static void -cpuacct_destroy(struct cgroup_subsys *ss, struct cgroup *cgrp) -{ - struct cpuacct *ca = cgroup_ca(cgrp); - int i; - - for (i = 0; i < CPUACCT_STAT_NSTATS; i++) - percpu_counter_destroy(&ca->cpustat[i]); - free_percpu(ca->cpuusage); - kfree(ca); -} - -static u64 cpuacct_cpuusage_read(struct cpuacct *ca, int cpu) -{ - u64 *cpuusage = per_cpu_ptr(ca->cpuusage, cpu); - u64 data; - -#ifndef CONFIG_64BIT - /* - * Take rq->lock to make 64-bit read safe on 32-bit platforms. - */ - spin_lock_irq(&cpu_rq(cpu)->lock); - data = *cpuusage; - spin_unlock_irq(&cpu_rq(cpu)->lock); -#else - data = *cpuusage; -#endif - - return data; -} - -static void cpuacct_cpuusage_write(struct cpuacct *ca, int cpu, u64 val) -{ - u64 *cpuusage = per_cpu_ptr(ca->cpuusage, cpu); - -#ifndef CONFIG_64BIT - /* - * Take rq->lock to make 64-bit write safe on 32-bit platforms. - */ - spin_lock_irq(&cpu_rq(cpu)->lock); - *cpuusage = val; - spin_unlock_irq(&cpu_rq(cpu)->lock); -#else - *cpuusage = val; -#endif -} - -/* return total cpu usage (in nanoseconds) of a group */ -static u64 cpuusage_read(struct cgroup *cgrp, struct cftype *cft) -{ - struct cpuacct *ca = cgroup_ca(cgrp); - u64 totalcpuusage = 0; - int i; - - for_each_present_cpu(i) - totalcpuusage += cpuacct_cpuusage_read(ca, i); - - return totalcpuusage; -} - -static int cpuusage_write(struct cgroup *cgrp, struct cftype *cftype, - u64 reset) -{ - struct cpuacct *ca = cgroup_ca(cgrp); - int err = 0; - int i; - - if (reset) { - err = -EINVAL; - goto out; - } - - for_each_present_cpu(i) - cpuacct_cpuusage_write(ca, i, 0); - -out: - return err; -} - -static int cpuacct_percpu_seq_read(struct cgroup *cgroup, struct cftype *cft, - struct seq_file *m) -{ - struct cpuacct *ca = cgroup_ca(cgroup); - u64 percpu; - int i; - - for_each_present_cpu(i) { - percpu = cpuacct_cpuusage_read(ca, i); - seq_printf(m, "%llu ", (unsigned long long) percpu); - } - seq_printf(m, "\n"); - return 0; -} - -static const char *cpuacct_stat_desc[] = { - [CPUACCT_STAT_USER] = "user", - [CPUACCT_STAT_SYSTEM] = "system", -}; - -static int cpuacct_stats_show(struct cgroup *cgrp, struct cftype *cft, - struct cgroup_map_cb *cb) -{ - struct cpuacct *ca = cgroup_ca(cgrp); - int i; - - for (i = 0; i < CPUACCT_STAT_NSTATS; i++) { - s64 val = percpu_counter_read(&ca->cpustat[i]); - val = cputime64_to_clock_t(val); - cb->fill(cb, cpuacct_stat_desc[i], val); - } - return 0; -} - -static struct cftype files[] = { - { - .name = "usage", - .read_u64 = cpuusage_read, - .write_u64 = cpuusage_write, - }, - { - .name = "usage_percpu", - .read_seq_string = cpuacct_percpu_seq_read, - }, - { - .name = "stat", - .read_map = cpuacct_stats_show, - }, -}; - -static int cpuacct_populate(struct cgroup_subsys *ss, struct cgroup *cgrp) -{ - return cgroup_add_files(cgrp, ss, files, ARRAY_SIZE(files)); -} - -/* - * charge this task's execution time to its accounting group. - * - * called with rq->lock held. - */ -static void cpuacct_charge(struct task_struct *tsk, u64 cputime) -{ - struct cpuacct *ca; - int cpu; - - if (unlikely(!cpuacct_subsys.active)) - return; - - cpu = task_cpu(tsk); - - rcu_read_lock(); - - ca = task_ca(tsk); - - for (; ca; ca = ca->parent) { - u64 *cpuusage = per_cpu_ptr(ca->cpuusage, cpu); - *cpuusage += cputime; - } - - rcu_read_unlock(); -} - -/* - * Charge the system/user time to the task's accounting group. - */ -static void cpuacct_update_stats(struct task_struct *tsk, - enum cpuacct_stat_index idx, cputime_t val) -{ - struct cpuacct *ca; - - if (unlikely(!cpuacct_subsys.active)) - return; - - rcu_read_lock(); - ca = task_ca(tsk); - - do { - percpu_counter_add(&ca->cpustat[idx], val); - ca = ca->parent; - } while (ca); - rcu_read_unlock(); -} - -struct cgroup_subsys cpuacct_subsys = { - .name = "cpuacct", - .create = cpuacct_create, - .destroy = cpuacct_destroy, - .populate = cpuacct_populate, - .subsys_id = cpuacct_subsys_id, -}; -#endif /* CONFIG_CGROUP_CPUACCT */ Index: linux-2.6.30-bfs/kernel/sysctl.c =================================================================== --- linux-2.6.30-bfs.orig/kernel/sysctl.c 2009-09-03 19:50:51.867053380 +1000 +++ linux-2.6.30-bfs/kernel/sysctl.c 2009-09-03 19:51:10.311054330 +1000 @@ -83,6 +83,8 @@ extern int compat_log; extern int latencytop_enabled; extern int sysctl_nr_open_min, sysctl_nr_open_max; +extern int rr_interval; +extern int sched_iso_cpu; #ifndef CONFIG_MMU extern int sysctl_nr_trim_pages; #endif @@ -97,10 +99,11 @@ #endif static int zero; -static int __maybe_unused one = 1; static int __maybe_unused two = 2; static unsigned long one_ul = 1; -static int one_hundred = 100; +static int __read_mostly one = 1; +static int __read_mostly one_hundred = 100; +static int __read_mostly five_thousand = 5000; /* this is needed for the proc_doulongvec_minmax of vm_dirty_bytes */ static unsigned long dirty_bytes_min = 2 * PAGE_SIZE; @@ -234,123 +237,7 @@ { .ctl_name = 0 } }; -#ifdef CONFIG_SCHED_DEBUG -static int min_sched_granularity_ns = 100000; /* 100 usecs */ -static int max_sched_granularity_ns = NSEC_PER_SEC; /* 1 second */ -static int min_wakeup_granularity_ns; /* 0 usecs */ -static int max_wakeup_granularity_ns = NSEC_PER_SEC; /* 1 second */ -#endif - static struct ctl_table kern_table[] = { -#ifdef CONFIG_SCHED_DEBUG - { - .ctl_name = CTL_UNNUMBERED, - .procname = "sched_min_granularity_ns", - .data = &sysctl_sched_min_granularity, - .maxlen = sizeof(unsigned int), - .mode = 0644, - .proc_handler = &sched_nr_latency_handler, - .strategy = &sysctl_intvec, - .extra1 = &min_sched_granularity_ns, - .extra2 = &max_sched_granularity_ns, - }, - { - .ctl_name = CTL_UNNUMBERED, - .procname = "sched_latency_ns", - .data = &sysctl_sched_latency, - .maxlen = sizeof(unsigned int), - .mode = 0644, - .proc_handler = &sched_nr_latency_handler, - .strategy = &sysctl_intvec, - .extra1 = &min_sched_granularity_ns, - .extra2 = &max_sched_granularity_ns, - }, - { - .ctl_name = CTL_UNNUMBERED, - .procname = "sched_wakeup_granularity_ns", - .data = &sysctl_sched_wakeup_granularity, - .maxlen = sizeof(unsigned int), - .mode = 0644, - .proc_handler = &proc_dointvec_minmax, - .strategy = &sysctl_intvec, - .extra1 = &min_wakeup_granularity_ns, - .extra2 = &max_wakeup_granularity_ns, - }, - { - .ctl_name = CTL_UNNUMBERED, - .procname = "sched_shares_ratelimit", - .data = &sysctl_sched_shares_ratelimit, - .maxlen = sizeof(unsigned int), - .mode = 0644, - .proc_handler = &proc_dointvec, - }, - { - .ctl_name = CTL_UNNUMBERED, - .procname = "sched_shares_thresh", - .data = &sysctl_sched_shares_thresh, - .maxlen = sizeof(unsigned int), - .mode = 0644, - .proc_handler = &proc_dointvec_minmax, - .strategy = &sysctl_intvec, - .extra1 = &zero, - }, - { - .ctl_name = CTL_UNNUMBERED, - .procname = "sched_child_runs_first", - .data = &sysctl_sched_child_runs_first, - .maxlen = sizeof(unsigned int), - .mode = 0644, - .proc_handler = &proc_dointvec, - }, - { - .ctl_name = CTL_UNNUMBERED, - .procname = "sched_features", - .data = &sysctl_sched_features, - .maxlen = sizeof(unsigned int), - .mode = 0644, - .proc_handler = &proc_dointvec, - }, - { - .ctl_name = CTL_UNNUMBERED, - .procname = "sched_migration_cost", - .data = &sysctl_sched_migration_cost, - .maxlen = sizeof(unsigned int), - .mode = 0644, - .proc_handler = &proc_dointvec, - }, - { - .ctl_name = CTL_UNNUMBERED, - .procname = "sched_nr_migrate", - .data = &sysctl_sched_nr_migrate, - .maxlen = sizeof(unsigned int), - .mode = 0644, - .proc_handler = &proc_dointvec, - }, -#endif - { - .ctl_name = CTL_UNNUMBERED, - .procname = "sched_rt_period_us", - .data = &sysctl_sched_rt_period, - .maxlen = sizeof(unsigned int), - .mode = 0644, - .proc_handler = &sched_rt_handler, - }, - { - .ctl_name = CTL_UNNUMBERED, - .procname = "sched_rt_runtime_us", - .data = &sysctl_sched_rt_runtime, - .maxlen = sizeof(int), - .mode = 0644, - .proc_handler = &sched_rt_handler, - }, - { - .ctl_name = CTL_UNNUMBERED, - .procname = "sched_compat_yield", - .data = &sysctl_sched_compat_yield, - .maxlen = sizeof(unsigned int), - .mode = 0644, - .proc_handler = &proc_dointvec, - }, #ifdef CONFIG_PROVE_LOCKING { .ctl_name = CTL_UNNUMBERED, @@ -756,6 +643,28 @@ .proc_handler = &proc_dointvec, }, #endif + { + .ctl_name = CTL_UNNUMBERED, + .procname = "rr_interval", + .data = &rr_interval, + .maxlen = sizeof (int), + .mode = 0644, + .proc_handler = &proc_dointvec_minmax, + .strategy = &sysctl_intvec, + .extra1 = &one, + .extra2 = &five_thousand, + }, + { + .ctl_name = CTL_UNNUMBERED, + .procname = "iso_cpu", + .data = &sched_iso_cpu, + .maxlen = sizeof (int), + .mode = 0644, + .proc_handler = &proc_dointvec_minmax, + .strategy = &sysctl_intvec, + .extra1 = &zero, + .extra2 = &one_hundred, + }, #if defined(CONFIG_S390) && defined(CONFIG_SMP) { .ctl_name = KERN_SPIN_RETRY, Index: linux-2.6.30-bfs/kernel/workqueue.c =================================================================== --- linux-2.6.30-bfs.orig/kernel/workqueue.c 2009-09-03 19:50:51.895053538 +1000 +++ linux-2.6.30-bfs/kernel/workqueue.c 2009-09-03 19:51:10.366061008 +1000 @@ -320,8 +320,6 @@ if (cwq->wq->freezeable) set_freezable(); - set_user_nice(current, -5); - for (;;) { prepare_to_wait(&cwq->more_work, &wait, TASK_INTERRUPTIBLE); if (!freezing(current) && Index: linux-2.6.30-bfs/kernel/sched_fair.c =================================================================== --- linux-2.6.30-bfs.orig/kernel/sched_fair.c 2009-09-03 19:50:51.837054274 +1000 +++ /dev/null 1970-01-01 00:00:00.000000000 +0000 @@ -1,1835 +0,0 @@ -/* - * Completely Fair Scheduling (CFS) Class (SCHED_NORMAL/SCHED_BATCH) - * - * Copyright (C) 2007 Red Hat, Inc., Ingo Molnar <mingo@redhat.com> - * - * Interactivity improvements by Mike Galbraith - * (C) 2007 Mike Galbraith <efault@gmx.de> - * - * Various enhancements by Dmitry Adamushko. - * (C) 2007 Dmitry Adamushko <dmitry.adamushko@gmail.com> - * - * Group scheduling enhancements by Srivatsa Vaddagiri - * Copyright IBM Corporation, 2007 - * Author: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> - * - * Scaled math optimizations by Thomas Gleixner - * Copyright (C) 2007, Thomas Gleixner <tglx@linutronix.de> - * - * Adaptive scheduling granularity, math enhancements by Peter Zijlstra - * Copyright (C) 2007 Red Hat, Inc., Peter Zijlstra <pzijlstr@redhat.com> - */ - -#include <linux/latencytop.h> - -/* - * Targeted preemption latency for CPU-bound tasks: - * (default: 20ms * (1 + ilog(ncpus)), units: nanoseconds) - * - * NOTE: this latency value is not the same as the concept of - * 'timeslice length' - timeslices in CFS are of variable length - * and have no persistent notion like in traditional, time-slice - * based scheduling concepts. - * - * (to see the precise effective timeslice length of your workload, - * run vmstat and monitor the context-switches (cs) field) - */ -unsigned int sysctl_sched_latency = 20000000ULL; - -/* - * Minimal preemption granularity for CPU-bound tasks: - * (default: 4 msec * (1 + ilog(ncpus)), units: nanoseconds) - */ -unsigned int sysctl_sched_min_granularity = 4000000ULL; - -/* - * is kept at sysctl_sched_latency / sysctl_sched_min_granularity - */ -static unsigned int sched_nr_latency = 5; - -/* - * After fork, child runs first. (default) If set to 0 then - * parent will (try to) run first. - */ -const_debug unsigned int sysctl_sched_child_runs_first = 1; - -/* - * sys_sched_yield() compat mode - * - * This option switches the agressive yield implementation of the - * old scheduler back on. - */ -unsigned int __read_mostly sysctl_sched_compat_yield; - -/* - * SCHED_OTHER wake-up granularity. - * (default: 5 msec * (1 + ilog(ncpus)), units: nanoseconds) - * - * This option delays the preemption effects of decoupled workloads - * and reduces their over-scheduling. Synchronous workloads will still - * have immediate wakeup/sleep latencies. - */ -unsigned int sysctl_sched_wakeup_granularity = 5000000UL; - -const_debug unsigned int sysctl_sched_migration_cost = 500000UL; - -static const struct sched_class fair_sched_class; - -/************************************************************** - * CFS operations on generic schedulable entities: - */ - -static inline struct task_struct *task_of(struct sched_entity *se) -{ - return container_of(se, struct task_struct, se); -} - -#ifdef CONFIG_FAIR_GROUP_SCHED - -/* cpu runqueue to which this cfs_rq is attached */ -static inline struct rq *rq_of(struct cfs_rq *cfs_rq) -{ - return cfs_rq->rq; -} - -/* An entity is a task if it doesn't "own" a runqueue */ -#define entity_is_task(se) (!se->my_q) - -/* Walk up scheduling entities hierarchy */ -#define for_each_sched_entity(se) \ - for (; se; se = se->parent) - -static inline struct cfs_rq *task_cfs_rq(struct task_struct *p) -{ - return p->se.cfs_rq; -} - -/* runqueue on which this entity is (to be) queued */ -static inline struct cfs_rq *cfs_rq_of(struct sched_entity *se) -{ - return se->cfs_rq; -} - -/* runqueue "owned" by this group */ -static inline struct cfs_rq *group_cfs_rq(struct sched_entity *grp) -{ - return grp->my_q; -} - -/* Given a group's cfs_rq on one cpu, return its corresponding cfs_rq on - * another cpu ('this_cpu') - */ -static inline struct cfs_rq *cpu_cfs_rq(struct cfs_rq *cfs_rq, int this_cpu) -{ - return cfs_rq->tg->cfs_rq[this_cpu]; -} - -/* Iterate thr' all leaf cfs_rq's on a runqueue */ -#define for_each_leaf_cfs_rq(rq, cfs_rq) \ - list_for_each_entry_rcu(cfs_rq, &rq->leaf_cfs_rq_list, leaf_cfs_rq_list) - -/* Do the two (enqueued) entities belong to the same group ? */ -static inline int -is_same_group(struct sched_entity *se, struct sched_entity *pse) -{ - if (se->cfs_rq == pse->cfs_rq) - return 1; - - return 0; -} - -static inline struct sched_entity *parent_entity(struct sched_entity *se) -{ - return se->parent; -} - -/* return depth at which a sched entity is present in the hierarchy */ -static inline int depth_se(struct sched_entity *se) -{ - int depth = 0; - - for_each_sched_entity(se) - depth++; - - return depth; -} - -static void -find_matching_se(struct sched_entity **se, struct sched_entity **pse) -{ - int se_depth, pse_depth; - - /* - * preemption test can be made between sibling entities who are in the - * same cfs_rq i.e who have a common parent. Walk up the hierarchy of - * both tasks until we find their ancestors who are siblings of common - * parent. - */ - - /* First walk up until both entities are at same depth */ - se_depth = depth_se(*se); - pse_depth = depth_se(*pse); - - while (se_depth > pse_depth) { - se_depth--; - *se = parent_entity(*se); - } - - while (pse_depth > se_depth) { - pse_depth--; - *pse = parent_entity(*pse); - } - - while (!is_same_group(*se, *pse)) { - *se = parent_entity(*se); - *pse = parent_entity(*pse); - } -} - -#else /* CONFIG_FAIR_GROUP_SCHED */ - -static inline struct rq *rq_of(struct cfs_rq *cfs_rq) -{ - return container_of(cfs_rq, struct rq, cfs); -} - -#define entity_is_task(se) 1 - -#define for_each_sched_entity(se) \ - for (; se; se = NULL) - -static inline struct cfs_rq *task_cfs_rq(struct task_struct *p) -{ - return &task_rq(p)->cfs; -} - -static inline struct cfs_rq *cfs_rq_of(struct sched_entity *se) -{ - struct task_struct *p = task_of(se); - struct rq *rq = task_rq(p); - - return &rq->cfs; -} - -/* runqueue "owned" by this group */ -static inline struct cfs_rq *group_cfs_rq(struct sched_entity *grp) -{ - return NULL; -} - -static inline struct cfs_rq *cpu_cfs_rq(struct cfs_rq *cfs_rq, int this_cpu) -{ - return &cpu_rq(this_cpu)->cfs; -} - -#define for_each_leaf_cfs_rq(rq, cfs_rq) \ - for (cfs_rq = &rq->cfs; cfs_rq; cfs_rq = NULL) - -static inline int -is_same_group(struct sched_entity *se, struct sched_entity *pse) -{ - return 1; -} - -static inline struct sched_entity *parent_entity(struct sched_entity *se) -{ - return NULL; -} - -static inline void -find_matching_se(struct sched_entity **se, struct sched_entity **pse) -{ -} - -#endif /* CONFIG_FAIR_GROUP_SCHED */ - - -/************************************************************** - * Scheduling class tree data structure manipulation methods: - */ - -static inline u64 max_vruntime(u64 min_vruntime, u64 vruntime) -{ - s64 delta = (s64)(vruntime - min_vruntime); - if (delta > 0) - min_vruntime = vruntime; - - return min_vruntime; -} - -static inline u64 min_vruntime(u64 min_vruntime, u64 vruntime) -{ - s64 delta = (s64)(vruntime - min_vruntime); - if (delta < 0) - min_vruntime = vruntime; - - return min_vruntime; -} - -static inline s64 entity_key(struct cfs_rq *cfs_rq, struct sched_entity *se) -{ - return se->vruntime - cfs_rq->min_vruntime; -} - -static void update_min_vruntime(struct cfs_rq *cfs_rq) -{ - u64 vruntime = cfs_rq->min_vruntime; - - if (cfs_rq->curr) - vruntime = cfs_rq->curr->vruntime; - - if (cfs_rq->rb_leftmost) { - struct sched_entity *se = rb_entry(cfs_rq->rb_leftmost, - struct sched_entity, - run_node); - - if (!cfs_rq->curr) - vruntime = se->vruntime; - else - vruntime = min_vruntime(vruntime, se->vruntime); - } - - cfs_rq->min_vruntime = max_vruntime(cfs_rq->min_vruntime, vruntime); -} - -/* - * Enqueue an entity into the rb-tree: - */ -static void __enqueue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se) -{ - struct rb_node **link = &cfs_rq->tasks_timeline.rb_node; - struct rb_node *parent = NULL; - struct sched_entity *entry; - s64 key = entity_key(cfs_rq, se); - int leftmost = 1; - - /* - * Find the right place in the rbtree: - */ - while (*link) { - parent = *link; - entry = rb_entry(parent, struct sched_entity, run_node); - /* - * We dont care about collisions. Nodes with - * the same key stay together. - */ - if (key < entity_key(cfs_rq, entry)) { - link = &parent->rb_left; - } else { - link = &parent->rb_right; - leftmost = 0; - } - } - - /* - * Maintain a cache of leftmost tree entries (it is frequently - * used): - */ - if (leftmost) - cfs_rq->rb_leftmost = &se->run_node; - - rb_link_node(&se->run_node, parent, link); - rb_insert_color(&se->run_node, &cfs_rq->tasks_timeline); -} - -static void __dequeue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se) -{ - if (cfs_rq->rb_leftmost == &se->run_node) { - struct rb_node *next_node; - - next_node = rb_next(&se->run_node); - cfs_rq->rb_leftmost = next_node; - } - - rb_erase(&se->run_node, &cfs_rq->tasks_timeline); -} - -static struct sched_entity *__pick_next_entity(struct cfs_rq *cfs_rq) -{ - struct rb_node *left = cfs_rq->rb_leftmost; - - if (!left) - return NULL; - - return rb_entry(left, struct sched_entity, run_node); -} - -static struct sched_entity *__pick_last_entity(struct cfs_rq *cfs_rq) -{ - struct rb_node *last = rb_last(&cfs_rq->tasks_timeline); - - if (!last) - return NULL; - - return rb_entry(last, struct sched_entity, run_node); -} - -/************************************************************** - * Scheduling class statistics methods: - */ - -#ifdef CONFIG_SCHED_DEBUG -int sched_nr_latency_handler(struct ctl_table *table, int write, - struct file *filp, void __user *buffer, size_t *lenp, - loff_t *ppos) -{ - int ret = proc_dointvec_minmax(table, write, filp, buffer, lenp, ppos); - - if (ret || !write) - return ret; - - sched_nr_latency = DIV_ROUND_UP(sysctl_sched_latency, - sysctl_sched_min_granularity); - - return 0; -} -#endif - -/* - * delta /= w - */ -static inline unsigned long -calc_delta_fair(unsigned long delta, struct sched_entity *se) -{ - if (unlikely(se->load.weight != NICE_0_LOAD)) - delta = calc_delta_mine(delta, NICE_0_LOAD, &se->load); - - return delta; -} - -/* - * The idea is to set a period in which each task runs once. - * - * When there are too many tasks (sysctl_sched_nr_latency) we have to stretch - * this period because otherwise the slices get too small. - * - * p = (nr <= nl) ? l : l*nr/nl - */ -static u64 __sched_period(unsigned long nr_running) -{ - u64 period = sysctl_sched_latency; - unsigned long nr_latency = sched_nr_latency; - - if (unlikely(nr_running > nr_latency)) { - period = sysctl_sched_min_granularity; - period *= nr_running; - } - - return period; -} - -/* - * We calculate the wall-time slice from the period by taking a part - * proportional to the weight. - * - * s = p*P[w/rw] - */ -static u64 sched_slice(struct cfs_rq *cfs_rq, struct sched_entity *se) -{ - u64 slice = __sched_period(cfs_rq->nr_running + !se->on_rq); - - for_each_sched_entity(se) { - struct load_weight *load; - - cfs_rq = cfs_rq_of(se); - load = &cfs_rq->load; - - if (unlikely(!se->on_rq)) { - struct load_weight lw = cfs_rq->load; - - update_load_add(&lw, se->load.weight); - load = &lw; - } - slice = calc_delta_mine(slice, se->load.weight, load); - } - return slice; -} - -/* - * We calculate the vruntime slice of a to be inserted task - * - * vs = s/w - */ -static u64 sched_vslice(struct cfs_rq *cfs_rq, struct sched_entity *se) -{ - return calc_delta_fair(sched_slice(cfs_rq, se), se); -} - -/* - * Update the current task's runtime statistics. Skip current tasks that - * are not in our scheduling class. - */ -static inline void -__update_curr(struct cfs_rq *cfs_rq, struct sched_entity *curr, - unsigned long delta_exec) -{ - unsigned long delta_exec_weighted; - - schedstat_set(curr->exec_max, max((u64)delta_exec, curr->exec_max)); - - curr->sum_exec_runtime += delta_exec; - schedstat_add(cfs_rq, exec_clock, delta_exec); - delta_exec_weighted = calc_delta_fair(delta_exec, curr); - curr->vruntime += delta_exec_weighted; - update_min_vruntime(cfs_rq); -} - -static void update_curr(struct cfs_rq *cfs_rq) -{ - struct sched_entity *curr = cfs_rq->curr; - u64 now = rq_of(cfs_rq)->clock; - unsigned long delta_exec; - - if (unlikely(!curr)) - return; - - /* - * Get the amount of time the current task was running - * since the last time we changed load (this cannot - * overflow on 32 bits): - */ - delta_exec = (unsigned long)(now - curr->exec_start); - if (!delta_exec) - return; - - __update_curr(cfs_rq, curr, delta_exec); - curr->exec_start = now; - - if (entity_is_task(curr)) { - struct task_struct *curtask = task_of(curr); - - cpuacct_charge(curtask, delta_exec); - account_group_exec_runtime(curtask, delta_exec); - } -} - -static inline void -update_stats_wait_start(struct cfs_rq *cfs_rq, struct sched_entity *se) -{ - schedstat_set(se->wait_start, rq_of(cfs_rq)->clock); -} - -/* - * Task is being enqueued - update stats: - */ -static void update_stats_enqueue(struct cfs_rq *cfs_rq, struct sched_entity *se) -{ - /* - * Are we enqueueing a waiting task? (for current tasks - * a dequeue/enqueue event is a NOP) - */ - if (se != cfs_rq->curr) - update_stats_wait_start(cfs_rq, se); -} - -static void -update_stats_wait_end(struct cfs_rq *cfs_rq, struct sched_entity *se) -{ - schedstat_set(se->wait_max, max(se->wait_max, - rq_of(cfs_rq)->clock - se->wait_start)); - schedstat_set(se->wait_count, se->wait_count + 1); - schedstat_set(se->wait_sum, se->wait_sum + - rq_of(cfs_rq)->clock - se->wait_start); - schedstat_set(se->wait_start, 0); -} - -static inline void -update_stats_dequeue(struct cfs_rq *cfs_rq, struct sched_entity *se) -{ - /* - * Mark the end of the wait period if dequeueing a - * waiting task: - */ - if (se != cfs_rq->curr) - update_stats_wait_end(cfs_rq, se); -} - -/* - * We are picking a new current task - update its stats: - */ -static inline void -update_stats_curr_start(struct cfs_rq *cfs_rq, struct sched_entity *se) -{ - /* - * We are starting a new run period: - */ - se->exec_start = rq_of(cfs_rq)->clock; -} - -/************************************************** - * Scheduling class queueing methods: - */ - -#if defined CONFIG_SMP && defined CONFIG_FAIR_GROUP_SCHED -static void -add_cfs_task_weight(struct cfs_rq *cfs_rq, unsigned long weight) -{ - cfs_rq->task_weight += weight; -} -#else -static inline void -add_cfs_task_weight(struct cfs_rq *cfs_rq, unsigned long weight) -{ -} -#endif - -static void -account_entity_enqueue(struct cfs_rq *cfs_rq, struct sched_entity *se) -{ - update_load_add(&cfs_rq->load, se->load.weight); - if (!parent_entity(se)) - inc_cpu_load(rq_of(cfs_rq), se->load.weight); - if (entity_is_task(se)) { - add_cfs_task_weight(cfs_rq, se->load.weight); - list_add(&se->group_node, &cfs_rq->tasks); - } - cfs_rq->nr_running++; - se->on_rq = 1; -} - -static void -account_entity_dequeue(struct cfs_rq *cfs_rq, struct sched_entity *se) -{ - update_load_sub(&cfs_rq->load, se->load.weight); - if (!parent_entity(se)) - dec_cpu_load(rq_of(cfs_rq), se->load.weight); - if (entity_is_task(se)) { - add_cfs_task_weight(cfs_rq, -se->load.weight); - list_del_init(&se->group_node); - } - cfs_rq->nr_running--; - se->on_rq = 0; -} - -static void enqueue_sleeper(struct cfs_rq *cfs_rq, struct sched_entity *se) -{ -#ifdef CONFIG_SCHEDSTATS - if (se->sleep_start) { - u64 delta = rq_of(cfs_rq)->clock - se->sleep_start; - struct task_struct *tsk = task_of(se); - - if ((s64)delta < 0) - delta = 0; - - if (unlikely(delta > se->sleep_max)) - se->sleep_max = delta; - - se->sleep_start = 0; - se->sum_sleep_runtime += delta; - - account_scheduler_latency(tsk, delta >> 10, 1); - } - if (se->block_start) { - u64 delta = rq_of(cfs_rq)->clock - se->block_start; - struct task_struct *tsk = task_of(se); - - if ((s64)delta < 0) - delta = 0; - - if (unlikely(delta > se->block_max)) - se->block_max = delta; - - se->block_start = 0; - se->sum_sleep_runtime += delta; - - /* - * Blocking time is in units of nanosecs, so shift by 20 to - * get a milliseconds-range estimation of the amount of - * time that the task spent sleeping: - */ - if (unlikely(prof_on == SLEEP_PROFILING)) { - - profile_hits(SLEEP_PROFILING, (void *)get_wchan(tsk), - delta >> 20); - } - account_scheduler_latency(tsk, delta >> 10, 0); - } -#endif -} - -static void check_spread(struct cfs_rq *cfs_rq, struct sched_entity *se) -{ -#ifdef CONFIG_SCHED_DEBUG - s64 d = se->vruntime - cfs_rq->min_vruntime; - - if (d < 0) - d = -d; - - if (d > 3*sysctl_sched_latency) - schedstat_inc(cfs_rq, nr_spread_over); -#endif -} - -static void -place_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int initial) -{ - u64 vruntime = cfs_rq->min_vruntime; - - /* - * The 'current' period is already promised to the current tasks, - * however the extra weight of the new task will slow them down a - * little, place the new task so that it fits in the slot that - * stays open at the end. - */ - if (initial && sched_feat(START_DEBIT)) - vruntime += sched_vslice(cfs_rq, se); - - if (!initial) { - /* sleeps upto a single latency don't count. */ - if (sched_feat(NEW_FAIR_SLEEPERS)) { - unsigned long thresh = sysctl_sched_latency; - - /* - * Convert the sleeper threshold into virtual time. - * SCHED_IDLE is a special sub-class. We care about - * fairness only relative to other SCHED_IDLE tasks, - * all of which have the same weight. - */ - if (sched_feat(NORMALIZED_SLEEPER) && - task_of(se)->policy != SCHED_IDLE) - thresh = calc_delta_fair(thresh, se); - - vruntime -= thresh; - } - - /* ensure we never gain time by being placed backwards. */ - vruntime = max_vruntime(se->vruntime, vruntime); - } - - se->vruntime = vruntime; -} - -static void -enqueue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int wakeup) -{ - /* - * Update run-time statistics of the 'current'. - */ - update_curr(cfs_rq); - account_entity_enqueue(cfs_rq, se); - - if (wakeup) { - place_entity(cfs_rq, se, 0); - enqueue_sleeper(cfs_rq, se); - } - - update_stats_enqueue(cfs_rq, se); - check_spread(cfs_rq, se); - if (se != cfs_rq->curr) - __enqueue_entity(cfs_rq, se); -} - -static void __clear_buddies(struct cfs_rq *cfs_rq, struct sched_entity *se) -{ - if (cfs_rq->last == se) - cfs_rq->last = NULL; - - if (cfs_rq->next == se) - cfs_rq->next = NULL; -} - -static void clear_buddies(struct cfs_rq *cfs_rq, struct sched_entity *se) -{ - for_each_sched_entity(se) - __clear_buddies(cfs_rq_of(se), se); -} - -static void -dequeue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int sleep) -{ - /* - * Update run-time statistics of the 'current'. - */ - update_curr(cfs_rq); - - update_stats_dequeue(cfs_rq, se); - if (sleep) { -#ifdef CONFIG_SCHEDSTATS - if (entity_is_task(se)) { - struct task_struct *tsk = task_of(se); - - if (tsk->state & TASK_INTERRUPTIBLE) - se->sleep_start = rq_of(cfs_rq)->clock; - if (tsk->state & TASK_UNINTERRUPTIBLE) - se->block_start = rq_of(cfs_rq)->clock; - } -#endif - } - - clear_buddies(cfs_rq, se); - - if (se != cfs_rq->curr) - __dequeue_entity(cfs_rq, se); - account_entity_dequeue(cfs_rq, se); - update_min_vruntime(cfs_rq); -} - -/* - * Preempt the current task with a newly woken task if needed: - */ -static void -check_preempt_tick(struct cfs_rq *cfs_rq, struct sched_entity *curr) -{ - unsigned long ideal_runtime, delta_exec; - - ideal_runtime = sched_slice(cfs_rq, curr); - delta_exec = curr->sum_exec_runtime - curr->prev_sum_exec_runtime; - if (delta_exec > ideal_runtime) { - resched_task(rq_of(cfs_rq)->curr); - /* - * The current task ran long enough, ensure it doesn't get - * re-elected due to buddy favours. - */ - clear_buddies(cfs_rq, curr); - } -} - -static void -set_next_entity(struct cfs_rq *cfs_rq, struct sched_entity *se) -{ - /* 'current' is not kept within the tree. */ - if (se->on_rq) { - /* - * Any task has to be enqueued before it get to execute on - * a CPU. So account for the time it spent waiting on the - * runqueue. - */ - update_stats_wait_end(cfs_rq, se); - __dequeue_entity(cfs_rq, se); - } - - update_stats_curr_start(cfs_rq, se); - cfs_rq->curr = se; -#ifdef CONFIG_SCHEDSTATS - /* - * Track our maximum slice length, if the CPU's load is at - * least twice that of our own weight (i.e. dont track it - * when there are only lesser-weight tasks around): - */ - if (rq_of(cfs_rq)->load.weight >= 2*se->load.weight) { - se->slice_max = max(se->slice_max, - se->sum_exec_runtime - se->prev_sum_exec_runtime); - } -#endif - se->prev_sum_exec_runtime = se->sum_exec_runtime; -} - -static int -wakeup_preempt_entity(struct sched_entity *curr, struct sched_entity *se); - -static struct sched_entity *pick_next_entity(struct cfs_rq *cfs_rq) -{ - struct sched_entity *se = __pick_next_entity(cfs_rq); - - if (cfs_rq->next && wakeup_preempt_entity(cfs_rq->next, se) < 1) - return cfs_rq->next; - - if (cfs_rq->last && wakeup_preempt_entity(cfs_rq->last, se) < 1) - return cfs_rq->last; - - return se; -} - -static void put_prev_entity(struct cfs_rq *cfs_rq, struct sched_entity *prev) -{ - /* - * If still on the runqueue then deactivate_task() - * was not called and update_curr() has to be done: - */ - if (prev->on_rq) - update_curr(cfs_rq); - - check_spread(cfs_rq, prev); - if (prev->on_rq) { - update_stats_wait_start(cfs_rq, prev); - /* Put 'current' back into the tree. */ - __enqueue_entity(cfs_rq, prev); - } - cfs_rq->curr = NULL; -} - -static void -entity_tick(struct cfs_rq *cfs_rq, struct sched_entity *curr, int queued) -{ - /* - * Update run-time statistics of the 'current'. - */ - update_curr(cfs_rq); - -#ifdef CONFIG_SCHED_HRTICK - /* - * queued ticks are scheduled to match the slice, so don't bother - * validating it and just reschedule. - */ - if (queued) { - resched_task(rq_of(cfs_rq)->curr); - return; - } - /* - * don't let the period tick interfere with the hrtick preemption - */ - if (!sched_feat(DOUBLE_TICK) && - hrtimer_active(&rq_of(cfs_rq)->hrtick_timer)) - return; -#endif - - if (cfs_rq->nr_running > 1 || !sched_feat(WAKEUP_PREEMPT)) - check_preempt_tick(cfs_rq, curr); -} - -/************************************************** - * CFS operations on tasks: - */ - -#ifdef CONFIG_SCHED_HRTICK -static void hrtick_start_fair(struct rq *rq, struct task_struct *p) -{ - struct sched_entity *se = &p->se; - struct cfs_rq *cfs_rq = cfs_rq_of(se); - - WARN_ON(task_rq(p) != rq); - - if (hrtick_enabled(rq) && cfs_rq->nr_running > 1) { - u64 slice = sched_slice(cfs_rq, se); - u64 ran = se->sum_exec_runtime - se->prev_sum_exec_runtime; - s64 delta = slice - ran; - - if (delta < 0) { - if (rq->curr == p) - resched_task(p); - return; - } - - /* - * Don't schedule slices shorter than 10000ns, that just - * doesn't make sense. Rely on vruntime for fairness. - */ - if (rq->curr != p) - delta = max_t(s64, 10000LL, delta); - - hrtick_start(rq, delta); - } -} - -/* - * called from enqueue/dequeue and updates the hrtick when the - * current task is from our class and nr_running is low enough - * to matter. - */ -static void hrtick_update(struct rq *rq) -{ - struct task_struct *curr = rq->curr; - - if (curr->sched_class != &fair_sched_class) - return; - - if (cfs_rq_of(&curr->se)->nr_running < sched_nr_latency) - hrtick_start_fair(rq, curr); -} -#else /* !CONFIG_SCHED_HRTICK */ -static inline void -hrtick_start_fair(struct rq *rq, struct task_struct *p) -{ -} - -static inline void hrtick_update(struct rq *rq) -{ -} -#endif - -/* - * The enqueue_task method is called before nr_running is - * increased. Here we update the fair scheduling stats and - * then put the task into the rbtree: - */ -static void enqueue_task_fair(struct rq *rq, struct task_struct *p, int wakeup) -{ - struct cfs_rq *cfs_rq; - struct sched_entity *se = &p->se; - - for_each_sched_entity(se) { - if (se->on_rq) - break; - cfs_rq = cfs_rq_of(se); - enqueue_entity(cfs_rq, se, wakeup); - wakeup = 1; - } - - hrtick_update(rq); -} - -/* - * The dequeue_task method is called before nr_running is - * decreased. We remove the task from the rbtree and - * update the fair scheduling stats: - */ -static void dequeue_task_fair(struct rq *rq, struct task_struct *p, int sleep) -{ - struct cfs_rq *cfs_rq; - struct sched_entity *se = &p->se; - - for_each_sched_entity(se) { - cfs_rq = cfs_rq_of(se); - dequeue_entity(cfs_rq, se, sleep); - /* Don't dequeue parent if it has other entities besides us */ - if (cfs_rq->load.weight) - break; - sleep = 1; - } - - hrtick_update(rq); -} - -/* - * sched_yield() support is very simple - we dequeue and enqueue. - * - * If compat_yield is turned on then we requeue to the end of the tree. - */ -static void yield_task_fair(struct rq *rq) -{ - struct task_struct *curr = rq->curr; - struct cfs_rq *cfs_rq = task_cfs_rq(curr); - struct sched_entity *rightmost, *se = &curr->se; - - /* - * Are we the only task in the tree? - */ - if (unlikely(cfs_rq->nr_running == 1)) - return; - - clear_buddies(cfs_rq, se); - - if (likely(!sysctl_sched_compat_yield) && curr->policy != SCHED_BATCH) { - update_rq_clock(rq); - /* - * Update run-time statistics of the 'current'. - */ - update_curr(cfs_rq); - - return; - } - /* - * Find the rightmost entry in the rbtree: - */ - rightmost = __pick_last_entity(cfs_rq); - /* - * Already in the rightmost position? - */ - if (unlikely(!rightmost || rightmost->vruntime < se->vruntime)) - return; - - /* - * Minimally necessary key value to be last in the tree: - * Upon rescheduling, sched_class::put_prev_task() will place - * 'current' within the tree based on its new key value. - */ - se->vruntime = rightmost->vruntime + 1; -} - -/* - * wake_idle() will wake a task on an idle cpu if task->cpu is - * not idle and an idle cpu is available. The span of cpus to - * search starts with cpus closest then further out as needed, - * so we always favor a closer, idle cpu. - * Domains may include CPUs that are not usable for migration, - * hence we need to mask them out (cpu_active_mask) - * - * Returns the CPU we should wake onto. - */ -#if defined(ARCH_HAS_SCHED_WAKE_IDLE) -static int wake_idle(int cpu, struct task_struct *p) -{ - struct sched_domain *sd; - int i; - unsigned int chosen_wakeup_cpu; - int this_cpu; - - /* - * At POWERSAVINGS_BALANCE_WAKEUP level, if both this_cpu and prev_cpu - * are idle and this is not a kernel thread and this task's affinity - * allows it to be moved to preferred cpu, then just move! - */ - - this_cpu = smp_processor_id(); - chosen_wakeup_cpu = - cpu_rq(this_cpu)->rd->sched_mc_preferred_wakeup_cpu; - - if (sched_mc_power_savings >= POWERSAVINGS_BALANCE_WAKEUP && - idle_cpu(cpu) && idle_cpu(this_cpu) && - p->mm && !(p->flags & PF_KTHREAD) && - cpu_isset(chosen_wakeup_cpu, p->cpus_allowed)) - return chosen_wakeup_cpu; - - /* - * If it is idle, then it is the best cpu to run this task. - * - * This cpu is also the best, if it has more than one task already. - * Siblings must be also busy(in most cases) as they didn't already - * pickup the extra load from this cpu and hence we need not check - * sibling runqueue info. This will avoid the checks and cache miss - * penalities associated with that. - */ - if (idle_cpu(cpu) || cpu_rq(cpu)->cfs.nr_running > 1) - return cpu; - - for_each_domain(cpu, sd) { - if ((sd->flags & SD_WAKE_IDLE) - || ((sd->flags & SD_WAKE_IDLE_FAR) - && !task_hot(p, task_rq(p)->clock, sd))) { - for_each_cpu_and(i, sched_domain_span(sd), - &p->cpus_allowed) { - if (cpu_active(i) && idle_cpu(i)) { - if (i != task_cpu(p)) { - schedstat_inc(p, - se.nr_wakeups_idle); - } - return i; - } - } - } else { - break; - } - } - return cpu; -} -#else /* !ARCH_HAS_SCHED_WAKE_IDLE*/ -static inline int wake_idle(int cpu, struct task_struct *p) -{ - return cpu; -} -#endif - -#ifdef CONFIG_SMP - -#ifdef CONFIG_FAIR_GROUP_SCHED -/* - * effective_load() calculates the load change as seen from the root_task_group - * - * Adding load to a group doesn't make a group heavier, but can cause movement - * of group shares between cpus. Assuming the shares were perfectly aligned one - * can calculate the shift in shares. - * - * The problem is that perfectly aligning the shares is rather expensive, hence - * we try to avoid doing that too often - see update_shares(), which ratelimits - * this change. - * - * We compensate this by not only taking the current delta into account, but - * also considering the delta between when the shares were last adjusted and - * now. - * - * We still saw a performance dip, some tracing learned us that between - * cgroup:/ and cgroup:/foo balancing the number of affine wakeups increased - * significantly. Therefore try to bias the error in direction of failing - * the affine wakeup. - * - */ -static long effective_load(struct task_group *tg, int cpu, - long wl, long wg) -{ - struct sched_entity *se = tg->se[cpu]; - - if (!tg->parent) - return wl; - - /* - * By not taking the decrease of shares on the other cpu into - * account our error leans towards reducing the affine wakeups. - */ - if (!wl && sched_feat(ASYM_EFF_LOAD)) - return wl; - - for_each_sched_entity(se) { - long S, rw, s, a, b; - long more_w; - - /* - * Instead of using this increment, also add the difference - * between when the shares were last updated and now. - */ - more_w = se->my_q->load.weight - se->my_q->rq_weight; - wl += more_w; - wg += more_w; - - S = se->my_q->tg->shares; - s = se->my_q->shares; - rw = se->my_q->rq_weight; - - a = S*(rw + wl); - b = S*rw + s*wg; - - wl = s*(a-b); - - if (likely(b)) - wl /= b; - - /* - * Assume the group is already running and will - * thus already be accounted for in the weight. - * - * That is, moving shares between CPUs, does not - * alter the group weight. - */ - wg = 0; - } - - return wl; -} - -#else - -static inline unsigned long effective_load(struct task_group *tg, int cpu, - unsigned long wl, unsigned long wg) -{ - return wl; -} - -#endif - -static int -wake_affine(struct sched_domain *this_sd, struct rq *this_rq, - struct task_struct *p, int prev_cpu, int this_cpu, int sync, - int idx, unsigned long load, unsigned long this_load, - unsigned int imbalance) -{ - struct task_struct *curr = this_rq->curr; - struct task_group *tg; - unsigned long tl = this_load; - unsigned long tl_per_task; - unsigned long weight; - int balanced; - - if (!(this_sd->flags & SD_WAKE_AFFINE) || !sched_feat(AFFINE_WAKEUPS)) - return 0; - - if (sync && (curr->se.avg_overlap > sysctl_sched_migration_cost || - p->se.avg_overlap > sysctl_sched_migration_cost)) - sync = 0; - - /* - * If sync wakeup then subtract the (maximum possible) - * effect of the currently running task from the load - * of the current CPU: - */ - if (sync) { - tg = task_group(current); - weight = current->se.load.weight; - - tl += effective_load(tg, this_cpu, -weight, -weight); - load += effective_load(tg, prev_cpu, 0, -weight); - } - - tg = task_group(p); - weight = p->se.load.weight; - - balanced = 100*(tl + effective_load(tg, this_cpu, weight, weight)) <= - imbalance*(load + effective_load(tg, prev_cpu, 0, weight)); - - /* - * If the currently running task will sleep within - * a reasonable amount of time then attract this newly - * woken task: - */ - if (sync && balanced) - return 1; - - schedstat_inc(p, se.nr_wakeups_affine_attempts); - tl_per_task = cpu_avg_load_per_task(this_cpu); - - if (balanced || (tl <= load && tl + target_load(prev_cpu, idx) <= - tl_per_task)) { - /* - * This domain has SD_WAKE_AFFINE and - * p is cache cold in this domain, and - * there is no bad imbalance. - */ - schedstat_inc(this_sd, ttwu_move_affine); - schedstat_inc(p, se.nr_wakeups_affine); - - return 1; - } - return 0; -} - -static int select_task_rq_fair(struct task_struct *p, int sync) -{ - struct sched_domain *sd, *this_sd = NULL; - int prev_cpu, this_cpu, new_cpu; - unsigned long load, this_load; - struct rq *this_rq; - unsigned int imbalance; - int idx; - - prev_cpu = task_cpu(p); - this_cpu = smp_processor_id(); - this_rq = cpu_rq(this_cpu); - new_cpu = prev_cpu; - - if (prev_cpu == this_cpu) - goto out; - /* - * 'this_sd' is the first domain that both - * this_cpu and prev_cpu are present in: - */ - for_each_domain(this_cpu, sd) { - if (cpumask_test_cpu(prev_cpu, sched_domain_span(sd))) { - this_sd = sd; - break; - } - } - - if (unlikely(!cpumask_test_cpu(this_cpu, &p->cpus_allowed))) - goto out; - - /* - * Check for affine wakeup and passive balancing possibilities. - */ - if (!this_sd) - goto out; - - idx = this_sd->wake_idx; - - imbalance = 100 + (this_sd->imbalance_pct - 100) / 2; - - load = source_load(prev_cpu, idx); - this_load = target_load(this_cpu, idx); - - if (wake_affine(this_sd, this_rq, p, prev_cpu, this_cpu, sync, idx, - load, this_load, imbalance)) - return this_cpu; - - /* - * Start passive balancing when half the imbalance_pct - * limit is reached. - */ - if (this_sd->flags & SD_WAKE_BALANCE) { - if (imbalance*this_load <= 100*load) { - schedstat_inc(this_sd, ttwu_move_balance); - schedstat_inc(p, se.nr_wakeups_passive); - return this_cpu; - } - } - -out: - return wake_idle(new_cpu, p); -} -#endif /* CONFIG_SMP */ - -/* - * Adaptive granularity - * - * se->avg_wakeup gives the average time a task runs until it does a wakeup, - * with the limit of wakeup_gran -- when it never does a wakeup. - * - * So the smaller avg_wakeup is the faster we want this task to preempt, - * but we don't want to treat the preemptee unfairly and therefore allow it - * to run for at least the amount of time we'd like to run. - * - * NOTE: we use 2*avg_wakeup to increase the probability of actually doing one - * - * NOTE: we use *nr_running to scale with load, this nicely matches the - * degrading latency on load. - */ -static unsigned long -adaptive_gran(struct sched_entity *curr, struct sched_entity *se) -{ - u64 this_run = curr->sum_exec_runtime - curr->prev_sum_exec_runtime; - u64 expected_wakeup = 2*se->avg_wakeup * cfs_rq_of(se)->nr_running; - u64 gran = 0; - - if (this_run < expected_wakeup) - gran = expected_wakeup - this_run; - - return min_t(s64, gran, sysctl_sched_wakeup_granularity); -} - -static unsigned long -wakeup_gran(struct sched_entity *curr, struct sched_entity *se) -{ - unsigned long gran = sysctl_sched_wakeup_granularity; - - if (cfs_rq_of(curr)->curr && sched_feat(ADAPTIVE_GRAN)) - gran = adaptive_gran(curr, se); - - /* - * Since its curr running now, convert the gran from real-time - * to virtual-time in his units. - */ - if (sched_feat(ASYM_GRAN)) { - /* - * By using 'se' instead of 'curr' we penalize light tasks, so - * they get preempted easier. That is, if 'se' < 'curr' then - * the resulting gran will be larger, therefore penalizing the - * lighter, if otoh 'se' > 'curr' then the resulting gran will - * be smaller, again penalizing the lighter task. - * - * This is especially important for buddies when the leftmost - * task is higher priority than the buddy. - */ - if (unlikely(se->load.weight != NICE_0_LOAD)) - gran = calc_delta_fair(gran, se); - } else { - if (unlikely(curr->load.weight != NICE_0_LOAD)) - gran = calc_delta_fair(gran, curr); - } - - return gran; -} - -/* - * Should 'se' preempt 'curr'. - * - * |s1 - * |s2 - * |s3 - * g - * |<--->|c - * - * w(c, s1) = -1 - * w(c, s2) = 0 - * w(c, s3) = 1 - * - */ -static int -wakeup_preempt_entity(struct sched_entity *curr, struct sched_entity *se) -{ - s64 gran, vdiff = curr->vruntime - se->vruntime; - - if (vdiff <= 0) - return -1; - - gran = wakeup_gran(curr, se); - if (vdiff > gran) - return 1; - - return 0; -} - -static void set_last_buddy(struct sched_entity *se) -{ - if (likely(task_of(se)->policy != SCHED_IDLE)) { - for_each_sched_entity(se) - cfs_rq_of(se)->last = se; - } -} - -static void set_next_buddy(struct sched_entity *se) -{ - if (likely(task_of(se)->policy != SCHED_IDLE)) { - for_each_sched_entity(se) - cfs_rq_of(se)->next = se; - } -} - -/* - * Preempt the current task with a newly woken task if needed: - */ -static void check_preempt_wakeup(struct rq *rq, struct task_struct *p, int sync) -{ - struct task_struct *curr = rq->curr; - struct sched_entity *se = &curr->se, *pse = &p->se; - struct cfs_rq *cfs_rq = task_cfs_rq(curr); - - update_curr(cfs_rq); - - if (unlikely(rt_prio(p->prio))) { - resched_task(curr); - return; - } - - if (unlikely(p->sched_class != &fair_sched_class)) - return; - - if (unlikely(se == pse)) - return; - - /* - * Only set the backward buddy when the current task is still on the - * rq. This can happen when a wakeup gets interleaved with schedule on - * the ->pre_schedule() or idle_balance() point, either of which can - * drop the rq lock. - * - * Also, during early boot the idle thread is in the fair class, for - * obvious reasons its a bad idea to schedule back to the idle thread. - */ - if (sched_feat(LAST_BUDDY) && likely(se->on_rq && curr != rq->idle)) - set_last_buddy(se); - set_next_buddy(pse); - - /* - * We can come here with TIF_NEED_RESCHED already set from new task - * wake up path. - */ - if (test_tsk_need_resched(curr)) - return; - - /* - * Batch and idle tasks do not preempt (their preemption is driven by - * the tick): - */ - if (unlikely(p->policy != SCHED_NORMAL)) - return; - - /* Idle tasks are by definition preempted by everybody. */ - if (unlikely(curr->policy == SCHED_IDLE)) { - resched_task(curr); - return; - } - - if (!sched_feat(WAKEUP_PREEMPT)) - return; - - if (sched_feat(WAKEUP_OVERLAP) && (sync || - (se->avg_overlap < sysctl_sched_migration_cost && - pse->avg_overlap < sysctl_sched_migration_cost))) { - resched_task(curr); - return; - } - - find_matching_se(&se, &pse); - - while (se) { - BUG_ON(!pse); - - if (wakeup_preempt_entity(se, pse) == 1) { - resched_task(curr); - break; - } - - se = parent_entity(se); - pse = parent_entity(pse); - } -} - -static struct task_struct *pick_next_task_fair(struct rq *rq) -{ - struct task_struct *p; - struct cfs_rq *cfs_rq = &rq->cfs; - struct sched_entity *se; - - if (unlikely(!cfs_rq->nr_running)) - return NULL; - - do { - se = pick_next_entity(cfs_rq); - /* - * If se was a buddy, clear it so that it will have to earn - * the favour again. - */ - __clear_buddies(cfs_rq, se); - set_next_entity(cfs_rq, se); - cfs_rq = group_cfs_rq(se); - } while (cfs_rq); - - p = task_of(se); - hrtick_start_fair(rq, p); - - return p; -} - -/* - * Account for a descheduled task: - */ -static void put_prev_task_fair(struct rq *rq, struct task_struct *prev) -{ - struct sched_entity *se = &prev->se; - struct cfs_rq *cfs_rq; - - for_each_sched_entity(se) { - cfs_rq = cfs_rq_of(se); - put_prev_entity(cfs_rq, se); - } -} - -#ifdef CONFIG_SMP -/************************************************** - * Fair scheduling class load-balancing methods: - */ - -/* - * Load-balancing iterator. Note: while the runqueue stays locked - * during the whole iteration, the current task might be - * dequeued so the iterator has to be dequeue-safe. Here we - * achieve that by always pre-iterating before returning - * the current task: - */ -static struct task_struct * -__load_balance_iterator(struct cfs_rq *cfs_rq, struct list_head *next) -{ - struct task_struct *p = NULL; - struct sched_entity *se; - - if (next == &cfs_rq->tasks) - return NULL; - - se = list_entry(next, struct sched_entity, group_node); - p = task_of(se); - cfs_rq->balance_iterator = next->next; - - return p; -} - -static struct task_struct *load_balance_start_fair(void *arg) -{ - struct cfs_rq *cfs_rq = arg; - - return __load_balance_iterator(cfs_rq, cfs_rq->tasks.next); -} - -static struct task_struct *load_balance_next_fair(void *arg) -{ - struct cfs_rq *cfs_rq = arg; - - return __load_balance_iterator(cfs_rq, cfs_rq->balance_iterator); -} - -static unsigned long -__load_balance_fair(struct rq *this_rq, int this_cpu, struct rq *busiest, - unsigned long max_load_move, struct sched_domain *sd, - enum cpu_idle_type idle, int *all_pinned, int *this_best_prio, - struct cfs_rq *cfs_rq) -{ - struct rq_iterator cfs_rq_iterator; - - cfs_rq_iterator.start = load_balance_start_fair; - cfs_rq_iterator.next = load_balance_next_fair; - cfs_rq_iterator.arg = cfs_rq; - - return balance_tasks(this_rq, this_cpu, busiest, - max_load_move, sd, idle, all_pinned, - this_best_prio, &cfs_rq_iterator); -} - -#ifdef CONFIG_FAIR_GROUP_SCHED -static unsigned long -load_balance_fair(struct rq *this_rq, int this_cpu, struct rq *busiest, - unsigned long max_load_move, - struct sched_domain *sd, enum cpu_idle_type idle, - int *all_pinned, int *this_best_prio) -{ - long rem_load_move = max_load_move; - int busiest_cpu = cpu_of(busiest); - struct task_group *tg; - - rcu_read_lock(); - update_h_load(busiest_cpu); - - list_for_each_entry_rcu(tg, &task_groups, list) { - struct cfs_rq *busiest_cfs_rq = tg->cfs_rq[busiest_cpu]; - unsigned long busiest_h_load = busiest_cfs_rq->h_load; - unsigned long busiest_weight = busiest_cfs_rq->load.weight; - u64 rem_load, moved_load; - - /* - * empty group - */ - if (!busiest_cfs_rq->task_weight) - continue; - - rem_load = (u64)rem_load_move * busiest_weight; - rem_load = div_u64(rem_load, busiest_h_load + 1); - - moved_load = __load_balance_fair(this_rq, this_cpu, busiest, - rem_load, sd, idle, all_pinned, this_best_prio, - tg->cfs_rq[busiest_cpu]); - - if (!moved_load) - continue; - - moved_load *= busiest_h_load; - moved_load = div_u64(moved_load, busiest_weight + 1); - - rem_load_move -= moved_load; - if (rem_load_move < 0) - break; - } - rcu_read_unlock(); - - return max_load_move - rem_load_move; -} -#else -static unsigned long -load_balance_fair(struct rq *this_rq, int this_cpu, struct rq *busiest, - unsigned long max_load_move, - struct sched_domain *sd, enum cpu_idle_type idle, - int *all_pinned, int *this_best_prio) -{ - return __load_balance_fair(this_rq, this_cpu, busiest, - max_load_move, sd, idle, all_pinned, - this_best_prio, &busiest->cfs); -} -#endif - -static int -move_one_task_fair(struct rq *this_rq, int this_cpu, struct rq *busiest, - struct sched_domain *sd, enum cpu_idle_type idle) -{ - struct cfs_rq *busy_cfs_rq; - struct rq_iterator cfs_rq_iterator; - - cfs_rq_iterator.start = load_balance_start_fair; - cfs_rq_iterator.next = load_balance_next_fair; - - for_each_leaf_cfs_rq(busiest, busy_cfs_rq) { - /* - * pass busy_cfs_rq argument into - * load_balance_[start|next]_fair iterators - */ - cfs_rq_iterator.arg = busy_cfs_rq; - if (iter_move_one_task(this_rq, this_cpu, busiest, sd, idle, - &cfs_rq_iterator)) - return 1; - } - - return 0; -} -#endif /* CONFIG_SMP */ - -/* - * scheduler tick hitting a task of our scheduling class: - */ -static void task_tick_fair(struct rq *rq, struct task_struct *curr, int queued) -{ - struct cfs_rq *cfs_rq; - struct sched_entity *se = &curr->se; - - for_each_sched_entity(se) { - cfs_rq = cfs_rq_of(se); - entity_tick(cfs_rq, se, queued); - } -} - -/* - * Share the fairness runtime between parent and child, thus the - * total amount of pressure for CPU stays equal - new tasks - * get a chance to run but frequent forkers are not allowed to - * monopolize the CPU. Note: the parent runqueue is locked, - * the child is not running yet. - */ -static void task_new_fair(struct rq *rq, struct task_struct *p) -{ - struct cfs_rq *cfs_rq = task_cfs_rq(p); - struct sched_entity *se = &p->se, *curr = cfs_rq->curr; - int this_cpu = smp_processor_id(); - - sched_info_queued(p); - - update_curr(cfs_rq); - place_entity(cfs_rq, se, 1); - - /* 'curr' will be NULL if the child belongs to a different group */ - if (sysctl_sched_child_runs_first && this_cpu == task_cpu(p) && - curr && curr->vruntime < se->vruntime) { - /* - * Upon rescheduling, sched_class::put_prev_task() will place - * 'current' within the tree based on its new key value. - */ - swap(curr->vruntime, se->vruntime); - resched_task(rq->curr); - } - - enqueue_task_fair(rq, p, 0); -} - -/* - * Priority of the task has changed. Check to see if we preempt - * the current task. - */ -static void prio_changed_fair(struct rq *rq, struct task_struct *p, - int oldprio, int running) -{ - /* - * Reschedule if we are currently running on this runqueue and - * our priority decreased, or if we are not currently running on - * this runqueue and our priority is higher than the current's - */ - if (running) { - if (p->prio > oldprio) - resched_task(rq->curr); - } else - check_preempt_curr(rq, p, 0); -} - -/* - * We switched to the sched_fair class. - */ -static void switched_to_fair(struct rq *rq, struct task_struct *p, - int running) -{ - /* - * We were most likely switched from sched_rt, so - * kick off the schedule if running, otherwise just see - * if we can still preempt the current task. - */ - if (running) - resched_task(rq->curr); - else - check_preempt_curr(rq, p, 0); -} - -/* Account for a task changing its policy or group. - * - * This routine is mostly called to set cfs_rq->curr field when a task - * migrates between groups/classes. - */ -static void set_curr_task_fair(struct rq *rq) -{ - struct sched_entity *se = &rq->curr->se; - - for_each_sched_entity(se) - set_next_entity(cfs_rq_of(se), se); -} - -#ifdef CONFIG_FAIR_GROUP_SCHED -static void moved_group_fair(struct task_struct *p) -{ - struct cfs_rq *cfs_rq = task_cfs_rq(p); - - update_curr(cfs_rq); - place_entity(cfs_rq, &p->se, 1); -} -#endif - -/* - * All the scheduling class methods: - */ -static const struct sched_class fair_sched_class = { - .next = &idle_sched_class, - .enqueue_task = enqueue_task_fair, - .dequeue_task = dequeue_task_fair, - .yield_task = yield_task_fair, - - .check_preempt_curr = check_preempt_wakeup, - - .pick_next_task = pick_next_task_fair, - .put_prev_task = put_prev_task_fair, - -#ifdef CONFIG_SMP - .select_task_rq = select_task_rq_fair, - - .load_balance = load_balance_fair, - .move_one_task = move_one_task_fair, -#endif - - .set_curr_task = set_curr_task_fair, - .task_tick = task_tick_fair, - .task_new = task_new_fair, - - .prio_changed = prio_changed_fair, - .switched_to = switched_to_fair, - -#ifdef CONFIG_FAIR_GROUP_SCHED - .moved_group = moved_group_fair, -#endif -}; - -#ifdef CONFIG_SCHED_DEBUG -static void print_cfs_stats(struct seq_file *m, int cpu) -{ - struct cfs_rq *cfs_rq; - - rcu_read_lock(); - for_each_leaf_cfs_rq(cpu_rq(cpu), cfs_rq) - print_cfs_rq(m, cpu, cfs_rq); - rcu_read_unlock(); -} -#endif Index: linux-2.6.30-bfs/kernel/sched_idletask.c =================================================================== --- linux-2.6.30-bfs.orig/kernel/sched_idletask.c 2009-09-03 19:50:51.819053823 +1000 +++ /dev/null 1970-01-01 00:00:00.000000000 +0000 @@ -1,128 +0,0 @@ -/* - * idle-task scheduling class. - * - * (NOTE: these are not related to SCHED_IDLE tasks which are - * handled in sched_fair.c) - */ - -#ifdef CONFIG_SMP -static int select_task_rq_idle(struct task_struct *p, int sync) -{ - return task_cpu(p); /* IDLE tasks as never migrated */ -} -#endif /* CONFIG_SMP */ -/* - * Idle tasks are unconditionally rescheduled: - */ -static void check_preempt_curr_idle(struct rq *rq, struct task_struct *p, int sync) -{ - resched_task(rq->idle); -} - -static struct task_struct *pick_next_task_idle(struct rq *rq) -{ - schedstat_inc(rq, sched_goidle); - - return rq->idle; -} - -/* - * It is not legal to sleep in the idle task - print a warning - * message if some code attempts to do it: - */ -static void -dequeue_task_idle(struct rq *rq, struct task_struct *p, int sleep) -{ - spin_unlock_irq(&rq->lock); - printk(KERN_ERR "bad: scheduling from the idle thread!\n"); - dump_stack(); - spin_lock_irq(&rq->lock); -} - -static void put_prev_task_idle(struct rq *rq, struct task_struct *prev) -{ -} - -#ifdef CONFIG_SMP -static unsigned long -load_balance_idle(struct rq *this_rq, int this_cpu, struct rq *busiest, - unsigned long max_load_move, - struct sched_domain *sd, enum cpu_idle_type idle, - int *all_pinned, int *this_best_prio) -{ - return 0; -} - -static int -move_one_task_idle(struct rq *this_rq, int this_cpu, struct rq *busiest, - struct sched_domain *sd, enum cpu_idle_type idle) -{ - return 0; -} -#endif - -static void task_tick_idle(struct rq *rq, struct task_struct *curr, int queued) -{ -} - -static void set_curr_task_idle(struct rq *rq) -{ -} - -static void switched_to_idle(struct rq *rq, struct task_struct *p, - int running) -{ - /* Can this actually happen?? */ - if (running) - resched_task(rq->curr); - else - check_preempt_curr(rq, p, 0); -} - -static void prio_changed_idle(struct rq *rq, struct task_struct *p, - int oldprio, int running) -{ - /* This can happen for hot plug CPUS */ - - /* - * Reschedule if we are currently running on this runqueue and - * our priority decreased, or if we are not currently running on - * this runqueue and our priority is higher than the current's - */ - if (running) { - if (p->prio > oldprio) - resched_task(rq->curr); - } else - check_preempt_curr(rq, p, 0); -} - -/* - * Simple, special scheduling class for the per-CPU idle tasks: - */ -static const struct sched_class idle_sched_class = { - /* .next is NULL */ - /* no enqueue/yield_task for idle tasks */ - - /* dequeue is not valid, we print a debug message there: */ - .dequeue_task = dequeue_task_idle, - - .check_preempt_curr = check_preempt_curr_idle, - - .pick_next_task = pick_next_task_idle, - .put_prev_task = put_prev_task_idle, - -#ifdef CONFIG_SMP - .select_task_rq = select_task_rq_idle, - - .load_balance = load_balance_idle, - .move_one_task = move_one_task_idle, -#endif - - .set_curr_task = set_curr_task_idle, - .task_tick = task_tick_idle, - - .prio_changed = prio_changed_idle, - .switched_to = switched_to_idle, - - /* no .task_new for idle tasks */ -}; Index: linux-2.6.30-bfs/kernel/sched_rt.c =================================================================== --- linux-2.6.30-bfs.orig/kernel/sched_rt.c 2009-09-03 19:50:51.850053370 +1000 +++ /dev/null 1970-01-01 00:00:00.000000000 +0000 @@ -1,1771 +0,0 @@ -/* - * Real-Time Scheduling Class (mapped to the SCHED_FIFO and SCHED_RR - * policies) - */ - -static inline struct task_struct *rt_task_of(struct sched_rt_entity *rt_se) -{ - return container_of(rt_se, struct task_struct, rt); -} - -#ifdef CONFIG_RT_GROUP_SCHED - -static inline struct rq *rq_of_rt_rq(struct rt_rq *rt_rq) -{ - return rt_rq->rq; -} - -static inline struct rt_rq *rt_rq_of_se(struct sched_rt_entity *rt_se) -{ - return rt_se->rt_rq; -} - -#else /* CONFIG_RT_GROUP_SCHED */ - -static inline struct rq *rq_of_rt_rq(struct rt_rq *rt_rq) -{ - return container_of(rt_rq, struct rq, rt); -} - -static inline struct rt_rq *rt_rq_of_se(struct sched_rt_entity *rt_se) -{ - struct task_struct *p = rt_task_of(rt_se); - struct rq *rq = task_rq(p); - - return &rq->rt; -} - -#endif /* CONFIG_RT_GROUP_SCHED */ - -#ifdef CONFIG_SMP - -static inline int rt_overloaded(struct rq *rq) -{ - return atomic_read(&rq->rd->rto_count); -} - -static inline void rt_set_overload(struct rq *rq) -{ - if (!rq->online) - return; - - cpumask_set_cpu(rq->cpu, rq->rd->rto_mask); - /* - * Make sure the mask is visible before we set - * the overload count. That is checked to determine - * if we should look at the mask. It would be a shame - * if we looked at the mask, but the mask was not - * updated yet. - */ - wmb(); - atomic_inc(&rq->rd->rto_count); -} - -static inline void rt_clear_overload(struct rq *rq) -{ - if (!rq->online) - return; - - /* the order here really doesn't matter */ - atomic_dec(&rq->rd->rto_count); - cpumask_clear_cpu(rq->cpu, rq->rd->rto_mask); -} - -static void update_rt_migration(struct rt_rq *rt_rq) -{ - if (rt_rq->rt_nr_migratory && (rt_rq->rt_nr_running > 1)) { - if (!rt_rq->overloaded) { - rt_set_overload(rq_of_rt_rq(rt_rq)); - rt_rq->overloaded = 1; - } - } else if (rt_rq->overloaded) { - rt_clear_overload(rq_of_rt_rq(rt_rq)); - rt_rq->overloaded = 0; - } -} - -static void inc_rt_migration(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq) -{ - if (rt_se->nr_cpus_allowed > 1) - rt_rq->rt_nr_migratory++; - - update_rt_migration(rt_rq); -} - -static void dec_rt_migration(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq) -{ - if (rt_se->nr_cpus_allowed > 1) - rt_rq->rt_nr_migratory--; - - update_rt_migration(rt_rq); -} - -static void enqueue_pushable_task(struct rq *rq, struct task_struct *p) -{ - plist_del(&p->pushable_tasks, &rq->rt.pushable_tasks); - plist_node_init(&p->pushable_tasks, p->prio); - plist_add(&p->pushable_tasks, &rq->rt.pushable_tasks); -} - -static void dequeue_pushable_task(struct rq *rq, struct task_struct *p) -{ - plist_del(&p->pushable_tasks, &rq->rt.pushable_tasks); -} - -#else - -static inline void enqueue_pushable_task(struct rq *rq, struct task_struct *p) -{ -} - -static inline void dequeue_pushable_task(struct rq *rq, struct task_struct *p) -{ -} - -static inline -void inc_rt_migration(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq) -{ -} - -static inline -void dec_rt_migration(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq) -{ -} - -#endif /* CONFIG_SMP */ - -static inline int on_rt_rq(struct sched_rt_entity *rt_se) -{ - return !list_empty(&rt_se->run_list); -} - -#ifdef CONFIG_RT_GROUP_SCHED - -static inline u64 sched_rt_runtime(struct rt_rq *rt_rq) -{ - if (!rt_rq->tg) - return RUNTIME_INF; - - return rt_rq->rt_runtime; -} - -static inline u64 sched_rt_period(struct rt_rq *rt_rq) -{ - return ktime_to_ns(rt_rq->tg->rt_bandwidth.rt_period); -} - -#define for_each_leaf_rt_rq(rt_rq, rq) \ - list_for_each_entry_rcu(rt_rq, &rq->leaf_rt_rq_list, leaf_rt_rq_list) - -#define for_each_sched_rt_entity(rt_se) \ - for (; rt_se; rt_se = rt_se->parent) - -static inline struct rt_rq *group_rt_rq(struct sched_rt_entity *rt_se) -{ - return rt_se->my_q; -} - -static void enqueue_rt_entity(struct sched_rt_entity *rt_se); -static void dequeue_rt_entity(struct sched_rt_entity *rt_se); - -static void sched_rt_rq_enqueue(struct rt_rq *rt_rq) -{ - struct task_struct *curr = rq_of_rt_rq(rt_rq)->curr; - struct sched_rt_entity *rt_se = rt_rq->rt_se; - - if (rt_rq->rt_nr_running) { - if (rt_se && !on_rt_rq(rt_se)) - enqueue_rt_entity(rt_se); - if (rt_rq->highest_prio.curr < curr->prio) - resched_task(curr); - } -} - -static void sched_rt_rq_dequeue(struct rt_rq *rt_rq) -{ - struct sched_rt_entity *rt_se = rt_rq->rt_se; - - if (rt_se && on_rt_rq(rt_se)) - dequeue_rt_entity(rt_se); -} - -static inline int rt_rq_throttled(struct rt_rq *rt_rq) -{ - return rt_rq->rt_throttled && !rt_rq->rt_nr_boosted; -} - -static int rt_se_boosted(struct sched_rt_entity *rt_se) -{ - struct rt_rq *rt_rq = group_rt_rq(rt_se); - struct task_struct *p; - - if (rt_rq) - return !!rt_rq->rt_nr_boosted; - - p = rt_task_of(rt_se); - return p->prio != p->normal_prio; -} - -#ifdef CONFIG_SMP -static inline const struct cpumask *sched_rt_period_mask(void) -{ - return cpu_rq(smp_processor_id())->rd->span; -} -#else -static inline const struct cpumask *sched_rt_period_mask(void) -{ - return cpu_online_mask; -} -#endif - -static inline -struct rt_rq *sched_rt_period_rt_rq(struct rt_bandwidth *rt_b, int cpu) -{ - return container_of(rt_b, struct task_group, rt_bandwidth)->rt_rq[cpu]; -} - -static inline struct rt_bandwidth *sched_rt_bandwidth(struct rt_rq *rt_rq) -{ - return &rt_rq->tg->rt_bandwidth; -} - -#else /* !CONFIG_RT_GROUP_SCHED */ - -static inline u64 sched_rt_runtime(struct rt_rq *rt_rq) -{ - return rt_rq->rt_runtime; -} - -static inline u64 sched_rt_period(struct rt_rq *rt_rq) -{ - return ktime_to_ns(def_rt_bandwidth.rt_period); -} - -#define for_each_leaf_rt_rq(rt_rq, rq) \ - for (rt_rq = &rq->rt; rt_rq; rt_rq = NULL) - -#define for_each_sched_rt_entity(rt_se) \ - for (; rt_se; rt_se = NULL) - -static inline struct rt_rq *group_rt_rq(struct sched_rt_entity *rt_se) -{ - return NULL; -} - -static inline void sched_rt_rq_enqueue(struct rt_rq *rt_rq) -{ - if (rt_rq->rt_nr_running) - resched_task(rq_of_rt_rq(rt_rq)->curr); -} - -static inline void sched_rt_rq_dequeue(struct rt_rq *rt_rq) -{ -} - -static inline int rt_rq_throttled(struct rt_rq *rt_rq) -{ - return rt_rq->rt_throttled; -} - -static inline const struct cpumask *sched_rt_period_mask(void) -{ - return cpu_online_mask; -} - -static inline -struct rt_rq *sched_rt_period_rt_rq(struct rt_bandwidth *rt_b, int cpu) -{ - return &cpu_rq(cpu)->rt; -} - -static inline struct rt_bandwidth *sched_rt_bandwidth(struct rt_rq *rt_rq) -{ - return &def_rt_bandwidth; -} - -#endif /* CONFIG_RT_GROUP_SCHED */ - -#ifdef CONFIG_SMP -/* - * We ran out of runtime, see if we can borrow some from our neighbours. - */ -static int do_balance_runtime(struct rt_rq *rt_rq) -{ - struct rt_bandwidth *rt_b = sched_rt_bandwidth(rt_rq); - struct root_domain *rd = cpu_rq(smp_processor_id())->rd; - int i, weight, more = 0; - u64 rt_period; - - weight = cpumask_weight(rd->span); - - spin_lock(&rt_b->rt_runtime_lock); - rt_period = ktime_to_ns(rt_b->rt_period); - for_each_cpu(i, rd->span) { - struct rt_rq *iter = sched_rt_period_rt_rq(rt_b, i); - s64 diff; - - if (iter == rt_rq) - continue; - - spin_lock(&iter->rt_runtime_lock); - /* - * Either all rqs have inf runtime and there's nothing to steal - * or __disable_runtime() below sets a specific rq to inf to - * indicate its been disabled and disalow stealing. - */ - if (iter->rt_runtime == RUNTIME_INF) - goto next; - - /* - * From runqueues with spare time, take 1/n part of their - * spare time, but no more than our period. - */ - diff = iter->rt_runtime - iter->rt_time; - if (diff > 0) { - diff = div_u64((u64)diff, weight); - if (rt_rq->rt_runtime + diff > rt_period) - diff = rt_period - rt_rq->rt_runtime; - iter->rt_runtime -= diff; - rt_rq->rt_runtime += diff; - more = 1; - if (rt_rq->rt_runtime == rt_period) { - spin_unlock(&iter->rt_runtime_lock); - break; - } - } -next: - spin_unlock(&iter->rt_runtime_lock); - } - spin_unlock(&rt_b->rt_runtime_lock); - - return more; -} - -/* - * Ensure this RQ takes back all the runtime it lend to its neighbours. - */ -static void __disable_runtime(struct rq *rq) -{ - struct root_domain *rd = rq->rd; - struct rt_rq *rt_rq; - - if (unlikely(!scheduler_running)) - return; - - for_each_leaf_rt_rq(rt_rq, rq) { - struct rt_bandwidth *rt_b = sched_rt_bandwidth(rt_rq); - s64 want; - int i; - - spin_lock(&rt_b->rt_runtime_lock); - spin_lock(&rt_rq->rt_runtime_lock); - /* - * Either we're all inf and nobody needs to borrow, or we're - * already disabled and thus have nothing to do, or we have - * exactly the right amount of runtime to take out. - */ - if (rt_rq->rt_runtime == RUNTIME_INF || - rt_rq->rt_runtime == rt_b->rt_runtime) - goto balanced; - spin_unlock(&rt_rq->rt_runtime_lock); - - /* - * Calculate the difference between what we started out with - * and what we current have, that's the amount of runtime - * we lend and now have to reclaim. - */ - want = rt_b->rt_runtime - rt_rq->rt_runtime; - - /* - * Greedy reclaim, take back as much as we can. - */ - for_each_cpu(i, rd->span) { - struct rt_rq *iter = sched_rt_period_rt_rq(rt_b, i); - s64 diff; - - /* - * Can't reclaim from ourselves or disabled runqueues. - */ - if (iter == rt_rq || iter->rt_runtime == RUNTIME_INF) - continue; - - spin_lock(&iter->rt_runtime_lock); - if (want > 0) { - diff = min_t(s64, iter->rt_runtime, want); - iter->rt_runtime -= diff; - want -= diff; - } else { - iter->rt_runtime -= want; - want -= want; - } - spin_unlock(&iter->rt_runtime_lock); - - if (!want) - break; - } - - spin_lock(&rt_rq->rt_runtime_lock); - /* - * We cannot be left wanting - that would mean some runtime - * leaked out of the system. - */ - BUG_ON(want); -balanced: - /* - * Disable all the borrow logic by pretending we have inf - * runtime - in which case borrowing doesn't make sense. - */ - rt_rq->rt_runtime = RUNTIME_INF; - spin_unlock(&rt_rq->rt_runtime_lock); - spin_unlock(&rt_b->rt_runtime_lock); - } -} - -static void disable_runtime(struct rq *rq) -{ - unsigned long flags; - - spin_lock_irqsave(&rq->lock, flags); - __disable_runtime(rq); - spin_unlock_irqrestore(&rq->lock, flags); -} - -static void __enable_runtime(struct rq *rq) -{ - struct rt_rq *rt_rq; - - if (unlikely(!scheduler_running)) - return; - - /* - * Reset each runqueue's bandwidth settings - */ - for_each_leaf_rt_rq(rt_rq, rq) { - struct rt_bandwidth *rt_b = sched_rt_bandwidth(rt_rq); - - spin_lock(&rt_b->rt_runtime_lock); - spin_lock(&rt_rq->rt_runtime_lock); - rt_rq->rt_runtime = rt_b->rt_runtime; - rt_rq->rt_time = 0; - rt_rq->rt_throttled = 0; - spin_unlock(&rt_rq->rt_runtime_lock); - spin_unlock(&rt_b->rt_runtime_lock); - } -} - -static void enable_runtime(struct rq *rq) -{ - unsigned long flags; - - spin_lock_irqsave(&rq->lock, flags); - __enable_runtime(rq); - spin_unlock_irqrestore(&rq->lock, flags); -} - -static int balance_runtime(struct rt_rq *rt_rq) -{ - int more = 0; - - if (rt_rq->rt_time > rt_rq->rt_runtime) { - spin_unlock(&rt_rq->rt_runtime_lock); - more = do_balance_runtime(rt_rq); - spin_lock(&rt_rq->rt_runtime_lock); - } - - return more; -} -#else /* !CONFIG_SMP */ -static inline int balance_runtime(struct rt_rq *rt_rq) -{ - return 0; -} -#endif /* CONFIG_SMP */ - -static int do_sched_rt_period_timer(struct rt_bandwidth *rt_b, int overrun) -{ - int i, idle = 1; - const struct cpumask *span; - - if (!rt_bandwidth_enabled() || rt_b->rt_runtime == RUNTIME_INF) - return 1; - - span = sched_rt_period_mask(); - for_each_cpu(i, span) { - int enqueue = 0; - struct rt_rq *rt_rq = sched_rt_period_rt_rq(rt_b, i); - struct rq *rq = rq_of_rt_rq(rt_rq); - - spin_lock(&rq->lock); - if (rt_rq->rt_time) { - u64 runtime; - - spin_lock(&rt_rq->rt_runtime_lock); - if (rt_rq->rt_throttled) - balance_runtime(rt_rq); - runtime = rt_rq->rt_runtime; - rt_rq->rt_time -= min(rt_rq->rt_time, overrun*runtime); - if (rt_rq->rt_throttled && rt_rq->rt_time < runtime) { - rt_rq->rt_throttled = 0; - enqueue = 1; - } - if (rt_rq->rt_time || rt_rq->rt_nr_running) - idle = 0; - spin_unlock(&rt_rq->rt_runtime_lock); - } else if (rt_rq->rt_nr_running) - idle = 0; - - if (enqueue) - sched_rt_rq_enqueue(rt_rq); - spin_unlock(&rq->lock); - } - - return idle; -} - -static inline int rt_se_prio(struct sched_rt_entity *rt_se) -{ -#ifdef CONFIG_RT_GROUP_SCHED - struct rt_rq *rt_rq = group_rt_rq(rt_se); - - if (rt_rq) - return rt_rq->highest_prio.curr; -#endif - - return rt_task_of(rt_se)->prio; -} - -static int sched_rt_runtime_exceeded(struct rt_rq *rt_rq) -{ - u64 runtime = sched_rt_runtime(rt_rq); - - if (rt_rq->rt_throttled) - return rt_rq_throttled(rt_rq); - - if (sched_rt_runtime(rt_rq) >= sched_rt_period(rt_rq)) - return 0; - - balance_runtime(rt_rq); - runtime = sched_rt_runtime(rt_rq); - if (runtime == RUNTIME_INF) - return 0; - - if (rt_rq->rt_time > runtime) { - rt_rq->rt_throttled = 1; - if (rt_rq_throttled(rt_rq)) { - sched_rt_rq_dequeue(rt_rq); - return 1; - } - } - - return 0; -} - -/* - * Update the current task's runtime statistics. Skip current tasks that - * are not in our scheduling class. - */ -static void update_curr_rt(struct rq *rq) -{ - struct task_struct *curr = rq->curr; - struct sched_rt_entity *rt_se = &curr->rt; - struct rt_rq *rt_rq = rt_rq_of_se(rt_se); - u64 delta_exec; - - if (!task_has_rt_policy(curr)) - return; - - delta_exec = rq->clock - curr->se.exec_start; - if (unlikely((s64)delta_exec < 0)) - delta_exec = 0; - - schedstat_set(curr->se.exec_max, max(curr->se.exec_max, delta_exec)); - - curr->se.sum_exec_runtime += delta_exec; - account_group_exec_runtime(curr, delta_exec); - - curr->se.exec_start = rq->clock; - cpuacct_charge(curr, delta_exec); - - if (!rt_bandwidth_enabled()) - return; - - for_each_sched_rt_entity(rt_se) { - rt_rq = rt_rq_of_se(rt_se); - - if (sched_rt_runtime(rt_rq) != RUNTIME_INF) { - spin_lock(&rt_rq->rt_runtime_lock); - rt_rq->rt_time += delta_exec; - if (sched_rt_runtime_exceeded(rt_rq)) - resched_task(curr); - spin_unlock(&rt_rq->rt_runtime_lock); - } - } -} - -#if defined CONFIG_SMP - -static struct task_struct *pick_next_highest_task_rt(struct rq *rq, int cpu); - -static inline int next_prio(struct rq *rq) -{ - struct task_struct *next = pick_next_highest_task_rt(rq, rq->cpu); - - if (next && rt_prio(next->prio)) - return next->prio; - else - return MAX_RT_PRIO; -} - -static void -inc_rt_prio_smp(struct rt_rq *rt_rq, int prio, int prev_prio) -{ - struct rq *rq = rq_of_rt_rq(rt_rq); - - if (prio < prev_prio) { - - /* - * If the new task is higher in priority than anything on the - * run-queue, we know that the previous high becomes our - * next-highest. - */ - rt_rq->highest_prio.next = prev_prio; - - if (rq->online) - cpupri_set(&rq->rd->cpupri, rq->cpu, prio); - - } else if (prio == rt_rq->highest_prio.curr) - /* - * If the next task is equal in priority to the highest on - * the run-queue, then we implicitly know that the next highest - * task cannot be any lower than current - */ - rt_rq->highest_prio.next = prio; - else if (prio < rt_rq->highest_prio.next) - /* - * Otherwise, we need to recompute next-highest - */ - rt_rq->highest_prio.next = next_prio(rq); -} - -static void -dec_rt_prio_smp(struct rt_rq *rt_rq, int prio, int prev_prio) -{ - struct rq *rq = rq_of_rt_rq(rt_rq); - - if (rt_rq->rt_nr_running && (prio <= rt_rq->highest_prio.next)) - rt_rq->highest_prio.next = next_prio(rq); - - if (rq->online && rt_rq->highest_prio.curr != prev_prio) - cpupri_set(&rq->rd->cpupri, rq->cpu, rt_rq->highest_prio.curr); -} - -#else /* CONFIG_SMP */ - -static inline -void inc_rt_prio_smp(struct rt_rq *rt_rq, int prio, int prev_prio) {} -static inline -void dec_rt_prio_smp(struct rt_rq *rt_rq, int prio, int prev_prio) {} - -#endif /* CONFIG_SMP */ - -#if defined CONFIG_SMP || defined CONFIG_RT_GROUP_SCHED -static void -inc_rt_prio(struct rt_rq *rt_rq, int prio) -{ - int prev_prio = rt_rq->highest_prio.curr; - - if (prio < prev_prio) - rt_rq->highest_prio.curr = prio; - - inc_rt_prio_smp(rt_rq, prio, prev_prio); -} - -static void -dec_rt_prio(struct rt_rq *rt_rq, int prio) -{ - int prev_prio = rt_rq->highest_prio.curr; - - if (rt_rq->rt_nr_running) { - - WARN_ON(prio < prev_prio); - - /* - * This may have been our highest task, and therefore - * we may have some recomputation to do - */ - if (prio == prev_prio) { - struct rt_prio_array *array = &rt_rq->active; - - rt_rq->highest_prio.curr = - sched_find_first_bit(array->bitmap); - } - - } else - rt_rq->highest_prio.curr = MAX_RT_PRIO; - - dec_rt_prio_smp(rt_rq, prio, prev_prio); -} - -#else - -static inline void inc_rt_prio(struct rt_rq *rt_rq, int prio) {} -static inline void dec_rt_prio(struct rt_rq *rt_rq, int prio) {} - -#endif /* CONFIG_SMP || CONFIG_RT_GROUP_SCHED */ - -#ifdef CONFIG_RT_GROUP_SCHED - -static void -inc_rt_group(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq) -{ - if (rt_se_boosted(rt_se)) - rt_rq->rt_nr_boosted++; - - if (rt_rq->tg) - start_rt_bandwidth(&rt_rq->tg->rt_bandwidth); -} - -static void -dec_rt_group(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq) -{ - if (rt_se_boosted(rt_se)) - rt_rq->rt_nr_boosted--; - - WARN_ON(!rt_rq->rt_nr_running && rt_rq->rt_nr_boosted); -} - -#else /* CONFIG_RT_GROUP_SCHED */ - -static void -inc_rt_group(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq) -{ - start_rt_bandwidth(&def_rt_bandwidth); -} - -static inline -void dec_rt_group(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq) {} - -#endif /* CONFIG_RT_GROUP_SCHED */ - -static inline -void inc_rt_tasks(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq) -{ - int prio = rt_se_prio(rt_se); - - WARN_ON(!rt_prio(prio)); - rt_rq->rt_nr_running++; - - inc_rt_prio(rt_rq, prio); - inc_rt_migration(rt_se, rt_rq); - inc_rt_group(rt_se, rt_rq); -} - -static inline -void dec_rt_tasks(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq) -{ - WARN_ON(!rt_prio(rt_se_prio(rt_se))); - WARN_ON(!rt_rq->rt_nr_running); - rt_rq->rt_nr_running--; - - dec_rt_prio(rt_rq, rt_se_prio(rt_se)); - dec_rt_migration(rt_se, rt_rq); - dec_rt_group(rt_se, rt_rq); -} - -static void __enqueue_rt_entity(struct sched_rt_entity *rt_se) -{ - struct rt_rq *rt_rq = rt_rq_of_se(rt_se); - struct rt_prio_array *array = &rt_rq->active; - struct rt_rq *group_rq = group_rt_rq(rt_se); - struct list_head *queue = array->queue + rt_se_prio(rt_se); - - /* - * Don't enqueue the group if its throttled, or when empty. - * The latter is a consequence of the former when a child group - * get throttled and the current group doesn't have any other - * active members. - */ - if (group_rq && (rt_rq_throttled(group_rq) || !group_rq->rt_nr_running)) - return; - - list_add_tail(&rt_se->run_list, queue); - __set_bit(rt_se_prio(rt_se), array->bitmap); - - inc_rt_tasks(rt_se, rt_rq); -} - -static void __dequeue_rt_entity(struct sched_rt_entity *rt_se) -{ - struct rt_rq *rt_rq = rt_rq_of_se(rt_se); - struct rt_prio_array *array = &rt_rq->active; - - list_del_init(&rt_se->run_list); - if (list_empty(array->queue + rt_se_prio(rt_se))) - __clear_bit(rt_se_prio(rt_se), array->bitmap); - - dec_rt_tasks(rt_se, rt_rq); -} - -/* - * Because the prio of an upper entry depends on the lower - * entries, we must remove entries top - down. - */ -static void dequeue_rt_stack(struct sched_rt_entity *rt_se) -{ - struct sched_rt_entity *back = NULL; - - for_each_sched_rt_entity(rt_se) { - rt_se->back = back; - back = rt_se; - } - - for (rt_se = back; rt_se; rt_se = rt_se->back) { - if (on_rt_rq(rt_se)) - __dequeue_rt_entity(rt_se); - } -} - -static void enqueue_rt_entity(struct sched_rt_entity *rt_se) -{ - dequeue_rt_stack(rt_se); - for_each_sched_rt_entity(rt_se) - __enqueue_rt_entity(rt_se); -} - -static void dequeue_rt_entity(struct sched_rt_entity *rt_se) -{ - dequeue_rt_stack(rt_se); - - for_each_sched_rt_entity(rt_se) { - struct rt_rq *rt_rq = group_rt_rq(rt_se); - - if (rt_rq && rt_rq->rt_nr_running) - __enqueue_rt_entity(rt_se); - } -} - -/* - * Adding/removing a task to/from a priority array: - */ -static void enqueue_task_rt(struct rq *rq, struct task_struct *p, int wakeup) -{ - struct sched_rt_entity *rt_se = &p->rt; - - if (wakeup) - rt_se->timeout = 0; - - enqueue_rt_entity(rt_se); - - if (!task_current(rq, p) && p->rt.nr_cpus_allowed > 1) - enqueue_pushable_task(rq, p); - - inc_cpu_load(rq, p->se.load.weight); -} - -static void dequeue_task_rt(struct rq *rq, struct task_struct *p, int sleep) -{ - struct sched_rt_entity *rt_se = &p->rt; - - update_curr_rt(rq); - dequeue_rt_entity(rt_se); - - dequeue_pushable_task(rq, p); - - dec_cpu_load(rq, p->se.load.weight); -} - -/* - * Put task to the end of the run list without the overhead of dequeue - * followed by enqueue. - */ -static void -requeue_rt_entity(struct rt_rq *rt_rq, struct sched_rt_entity *rt_se, int head) -{ - if (on_rt_rq(rt_se)) { - struct rt_prio_array *array = &rt_rq->active; - struct list_head *queue = array->queue + rt_se_prio(rt_se); - - if (head) - list_move(&rt_se->run_list, queue); - else - list_move_tail(&rt_se->run_list, queue); - } -} - -static void requeue_task_rt(struct rq *rq, struct task_struct *p, int head) -{ - struct sched_rt_entity *rt_se = &p->rt; - struct rt_rq *rt_rq; - - for_each_sched_rt_entity(rt_se) { - rt_rq = rt_rq_of_se(rt_se); - requeue_rt_entity(rt_rq, rt_se, head); - } -} - -static void yield_task_rt(struct rq *rq) -{ - requeue_task_rt(rq, rq->curr, 0); -} - -#ifdef CONFIG_SMP -static int find_lowest_rq(struct task_struct *task); - -static int select_task_rq_rt(struct task_struct *p, int sync) -{ - struct rq *rq = task_rq(p); - - /* - * If the current task is an RT task, then - * try to see if we can wake this RT task up on another - * runqueue. Otherwise simply start this RT task - * on its current runqueue. - * - * We want to avoid overloading runqueues. Even if - * the RT task is of higher priority than the current RT task. - * RT tasks behave differently than other tasks. If - * one gets preempted, we try to push it off to another queue. - * So trying to keep a preempting RT task on the same - * cache hot CPU will force the running RT task to - * a cold CPU. So we waste all the cache for the lower - * RT task in hopes of saving some of a RT task - * that is just being woken and probably will have - * cold cache anyway. - */ - if (unlikely(rt_task(rq->curr)) && - (p->rt.nr_cpus_allowed > 1)) { - int cpu = find_lowest_rq(p); - - return (cpu == -1) ? task_cpu(p) : cpu; - } - - /* - * Otherwise, just let it ride on the affined RQ and the - * post-schedule router will push the preempted task away - */ - return task_cpu(p); -} - -static void check_preempt_equal_prio(struct rq *rq, struct task_struct *p) -{ - if (rq->curr->rt.nr_cpus_allowed == 1) - return; - - if (p->rt.nr_cpus_allowed != 1 - && cpupri_find(&rq->rd->cpupri, p, NULL)) - return; - - if (!cpupri_find(&rq->rd->cpupri, rq->curr, NULL)) - return; - - /* - * There appears to be other cpus that can accept - * current and none to run 'p', so lets reschedule - * to try and push current away: - */ - requeue_task_rt(rq, p, 1); - resched_task(rq->curr); -} - -#endif /* CONFIG_SMP */ - -/* - * Preempt the current task with a newly woken task if needed: - */ -static void check_preempt_curr_rt(struct rq *rq, struct task_struct *p, int sync) -{ - if (p->prio < rq->curr->prio) { - resched_task(rq->curr); - return; - } - -#ifdef CONFIG_SMP - /* - * If: - * - * - the newly woken task is of equal priority to the current task - * - the newly woken task is non-migratable while current is migratable - * - current will be preempted on the next reschedule - * - * we should check to see if current can readily move to a different - * cpu. If so, we will reschedule to allow the push logic to try - * to move current somewhere else, making room for our non-migratable - * task. - */ - if (p->prio == rq->curr->prio && !need_resched()) - check_preempt_equal_prio(rq, p); -#endif -} - -static struct sched_rt_entity *pick_next_rt_entity(struct rq *rq, - struct rt_rq *rt_rq) -{ - struct rt_prio_array *array = &rt_rq->active; - struct sched_rt_entity *next = NULL; - struct list_head *queue; - int idx; - - idx = sched_find_first_bit(array->bitmap); - BUG_ON(idx >= MAX_RT_PRIO); - - queue = array->queue + idx; - next = list_entry(queue->next, struct sched_rt_entity, run_list); - - return next; -} - -static struct task_struct *_pick_next_task_rt(struct rq *rq) -{ - struct sched_rt_entity *rt_se; - struct task_struct *p; - struct rt_rq *rt_rq; - - rt_rq = &rq->rt; - - if (unlikely(!rt_rq->rt_nr_running)) - return NULL; - - if (rt_rq_throttled(rt_rq)) - return NULL; - - do { - rt_se = pick_next_rt_entity(rq, rt_rq); - BUG_ON(!rt_se); - rt_rq = group_rt_rq(rt_se); - } while (rt_rq); - - p = rt_task_of(rt_se); - p->se.exec_start = rq->clock; - - return p; -} - -static struct task_struct *pick_next_task_rt(struct rq *rq) -{ - struct task_struct *p = _pick_next_task_rt(rq); - - /* The running task is never eligible for pushing */ - if (p) - dequeue_pushable_task(rq, p); - - return p; -} - -static void put_prev_task_rt(struct rq *rq, struct task_struct *p) -{ - update_curr_rt(rq); - p->se.exec_start = 0; - - /* - * The previous task needs to be made eligible for pushing - * if it is still active - */ - if (p->se.on_rq && p->rt.nr_cpus_allowed > 1) - enqueue_pushable_task(rq, p); -} - -#ifdef CONFIG_SMP - -/* Only try algorithms three times */ -#define RT_MAX_TRIES 3 - -static void deactivate_task(struct rq *rq, struct task_struct *p, int sleep); - -static int pick_rt_task(struct rq *rq, struct task_struct *p, int cpu) -{ - if (!task_running(rq, p) && - (cpu < 0 || cpumask_test_cpu(cpu, &p->cpus_allowed)) && - (p->rt.nr_cpus_allowed > 1)) - return 1; - return 0; -} - -/* Return the second highest RT task, NULL otherwise */ -static struct task_struct *pick_next_highest_task_rt(struct rq *rq, int cpu) -{ - struct task_struct *next = NULL; - struct sched_rt_entity *rt_se; - struct rt_prio_array *array; - struct rt_rq *rt_rq; - int idx; - - for_each_leaf_rt_rq(rt_rq, rq) { - array = &rt_rq->active; - idx = sched_find_first_bit(array->bitmap); - next_idx: - if (idx >= MAX_RT_PRIO) - continue; - if (next && next->prio < idx) - continue; - list_for_each_entry(rt_se, array->queue + idx, run_list) { - struct task_struct *p = rt_task_of(rt_se); - if (pick_rt_task(rq, p, cpu)) { - next = p; - break; - } - } - if (!next) { - idx = find_next_bit(array->bitmap, MAX_RT_PRIO, idx+1); - goto next_idx; - } - } - - return next; -} - -static DEFINE_PER_CPU(cpumask_var_t, local_cpu_mask); - -static inline int pick_optimal_cpu(int this_cpu, - const struct cpumask *mask) -{ - int first; - - /* "this_cpu" is cheaper to preempt than a remote processor */ - if ((this_cpu != -1) && cpumask_test_cpu(this_cpu, mask)) - return this_cpu; - - first = cpumask_first(mask); - if (first < nr_cpu_ids) - return first; - - return -1; -} - -static int find_lowest_rq(struct task_struct *task) -{ - struct sched_domain *sd; - struct cpumask *lowest_mask = __get_cpu_var(local_cpu_mask); - int this_cpu = smp_processor_id(); - int cpu = task_cpu(task); - cpumask_var_t domain_mask; - - if (task->rt.nr_cpus_allowed == 1) - return -1; /* No other targets possible */ - - if (!cpupri_find(&task_rq(task)->rd->cpupri, task, lowest_mask)) - return -1; /* No targets found */ - - /* - * Only consider CPUs that are usable for migration. - * I guess we might want to change cpupri_find() to ignore those - * in the first place. - */ - cpumask_and(lowest_mask, lowest_mask, cpu_active_mask); - - /* - * At this point we have built a mask of cpus representing the - * lowest priority tasks in the system. Now we want to elect - * the best one based on our affinity and topology. - * - * We prioritize the last cpu that the task executed on since - * it is most likely cache-hot in that location. - */ - if (cpumask_test_cpu(cpu, lowest_mask)) - return cpu; - - /* - * Otherwise, we consult the sched_domains span maps to figure - * out which cpu is logically closest to our hot cache data. - */ - if (this_cpu == cpu) - this_cpu = -1; /* Skip this_cpu opt if the same */ - - if (alloc_cpumask_var(&domain_mask, GFP_ATOMIC)) { - for_each_domain(cpu, sd) { - if (sd->flags & SD_WAKE_AFFINE) { - int best_cpu; - - cpumask_and(domain_mask, - sched_domain_span(sd), - lowest_mask); - - best_cpu = pick_optimal_cpu(this_cpu, - domain_mask); - - if (best_cpu != -1) { - free_cpumask_var(domain_mask); - return best_cpu; - } - } - } - free_cpumask_var(domain_mask); - } - - /* - * And finally, if there were no matches within the domains - * just give the caller *something* to work with from the compatible - * locations. - */ - return pick_optimal_cpu(this_cpu, lowest_mask); -} - -/* Will lock the rq it finds */ -static struct rq *find_lock_lowest_rq(struct task_struct *task, struct rq *rq) -{ - struct rq *lowest_rq = NULL; - int tries; - int cpu; - - for (tries = 0; tries < RT_MAX_TRIES; tries++) { - cpu = find_lowest_rq(task); - - if ((cpu == -1) || (cpu == rq->cpu)) - break; - - lowest_rq = cpu_rq(cpu); - - /* if the prio of this runqueue changed, try again */ - if (double_lock_balance(rq, lowest_rq)) { - /* - * We had to unlock the run queue. In - * the mean time, task could have - * migrated already or had its affinity changed. - * Also make sure that it wasn't scheduled on its rq. - */ - if (unlikely(task_rq(task) != rq || - !cpumask_test_cpu(lowest_rq->cpu, - &task->cpus_allowed) || - task_running(rq, task) || - !task->se.on_rq)) { - - spin_unlock(&lowest_rq->lock); - lowest_rq = NULL; - break; - } - } - - /* If this rq is still suitable use it. */ - if (lowest_rq->rt.highest_prio.curr > task->prio) - break; - - /* try again */ - double_unlock_balance(rq, lowest_rq); - lowest_rq = NULL; - } - - return lowest_rq; -} - -static inline int has_pushable_tasks(struct rq *rq) -{ - return !plist_head_empty(&rq->rt.pushable_tasks); -} - -static struct task_struct *pick_next_pushable_task(struct rq *rq) -{ - struct task_struct *p; - - if (!has_pushable_tasks(rq)) - return NULL; - - p = plist_first_entry(&rq->rt.pushable_tasks, - struct task_struct, pushable_tasks); - - BUG_ON(rq->cpu != task_cpu(p)); - BUG_ON(task_current(rq, p)); - BUG_ON(p->rt.nr_cpus_allowed <= 1); - - BUG_ON(!p->se.on_rq); - BUG_ON(!rt_task(p)); - - return p; -} - -/* - * If the current CPU has more than one RT task, see if the non - * running task can migrate over to a CPU that is running a task - * of lesser priority. - */ -static int push_rt_task(struct rq *rq) -{ - struct task_struct *next_task; - struct rq *lowest_rq; - - if (!rq->rt.overloaded) - return 0; - - next_task = pick_next_pushable_task(rq); - if (!next_task) - return 0; - - retry: - if (unlikely(next_task == rq->curr)) { - WARN_ON(1); - return 0; - } - - /* - * It's possible that the next_task slipped in of - * higher priority than current. If that's the case - * just reschedule current. - */ - if (unlikely(next_task->prio < rq->curr->prio)) { - resched_task(rq->curr); - return 0; - } - - /* We might release rq lock */ - get_task_struct(next_task); - - /* find_lock_lowest_rq locks the rq if found */ - lowest_rq = find_lock_lowest_rq(next_task, rq); - if (!lowest_rq) { - struct task_struct *task; - /* - * find lock_lowest_rq releases rq->lock - * so it is possible that next_task has migrated. - * - * We need to make sure that the task is still on the same - * run-queue and is also still the next task eligible for - * pushing. - */ - task = pick_next_pushable_task(rq); - if (task_cpu(next_task) == rq->cpu && task == next_task) { - /* - * If we get here, the task hasnt moved at all, but - * it has failed to push. We will not try again, - * since the other cpus will pull from us when they - * are ready. - */ - dequeue_pushable_task(rq, next_task); - goto out; - } - - if (!task) - /* No more tasks, just exit */ - goto out; - - /* - * Something has shifted, try again. - */ - put_task_struct(next_task); - next_task = task; - goto retry; - } - - deactivate_task(rq, next_task, 0); - set_task_cpu(next_task, lowest_rq->cpu); - activate_task(lowest_rq, next_task, 0); - - resched_task(lowest_rq->curr); - - double_unlock_balance(rq, lowest_rq); - -out: - put_task_struct(next_task); - - return 1; -} - -static void push_rt_tasks(struct rq *rq) -{ - /* push_rt_task will return true if it moved an RT */ - while (push_rt_task(rq)) - ; -} - -static int pull_rt_task(struct rq *this_rq) -{ - int this_cpu = this_rq->cpu, ret = 0, cpu; - struct task_struct *p; - struct rq *src_rq; - - if (likely(!rt_overloaded(this_rq))) - return 0; - - for_each_cpu(cpu, this_rq->rd->rto_mask) { - if (this_cpu == cpu) - continue; - - src_rq = cpu_rq(cpu); - - /* - * Don't bother taking the src_rq->lock if the next highest - * task is known to be lower-priority than our current task. - * This may look racy, but if this value is about to go - * logically higher, the src_rq will push this task away. - * And if its going logically lower, we do not care - */ - if (src_rq->rt.highest_prio.next >= - this_rq->rt.highest_prio.curr) - continue; - - /* - * We can potentially drop this_rq's lock in - * double_lock_balance, and another CPU could - * alter this_rq - */ - double_lock_balance(this_rq, src_rq); - - /* - * Are there still pullable RT tasks? - */ - if (src_rq->rt.rt_nr_running <= 1) - goto skip; - - p = pick_next_highest_task_rt(src_rq, this_cpu); - - /* - * Do we have an RT task that preempts - * the to-be-scheduled task? - */ - if (p && (p->prio < this_rq->rt.highest_prio.curr)) { - WARN_ON(p == src_rq->curr); - WARN_ON(!p->se.on_rq); - - /* - * There's a chance that p is higher in priority - * than what's currently running on its cpu. - * This is just that p is wakeing up and hasn't - * had a chance to schedule. We only pull - * p if it is lower in priority than the - * current task on the run queue - */ - if (p->prio < src_rq->curr->prio) - goto skip; - - ret = 1; - - deactivate_task(src_rq, p, 0); - set_task_cpu(p, this_cpu); - activate_task(this_rq, p, 0); - /* - * We continue with the search, just in - * case there's an even higher prio task - * in another runqueue. (low likelyhood - * but possible) - */ - } - skip: - double_unlock_balance(this_rq, src_rq); - } - - return ret; -} - -static void pre_schedule_rt(struct rq *rq, struct task_struct *prev) -{ - /* Try to pull RT tasks here if we lower this rq's prio */ - if (unlikely(rt_task(prev)) && rq->rt.highest_prio.curr > prev->prio) - pull_rt_task(rq); -} - -/* - * assumes rq->lock is held - */ -static int needs_post_schedule_rt(struct rq *rq) -{ - return has_pushable_tasks(rq); -} - -static void post_schedule_rt(struct rq *rq) -{ - /* - * This is only called if needs_post_schedule_rt() indicates that - * we need to push tasks away - */ - spin_lock_irq(&rq->lock); - push_rt_tasks(rq); - spin_unlock_irq(&rq->lock); -} - -/* - * If we are not running and we are not going to reschedule soon, we should - * try to push tasks away now - */ -static void task_wake_up_rt(struct rq *rq, struct task_struct *p) -{ - if (!task_running(rq, p) && - !test_tsk_need_resched(rq->curr) && - has_pushable_tasks(rq) && - p->rt.nr_cpus_allowed > 1) - push_rt_tasks(rq); -} - -static unsigned long -load_balance_rt(struct rq *this_rq, int this_cpu, struct rq *busiest, - unsigned long max_load_move, - struct sched_domain *sd, enum cpu_idle_type idle, - int *all_pinned, int *this_best_prio) -{ - /* don't touch RT tasks */ - return 0; -} - -static int -move_one_task_rt(struct rq *this_rq, int this_cpu, struct rq *busiest, - struct sched_domain *sd, enum cpu_idle_type idle) -{ - /* don't touch RT tasks */ - return 0; -} - -static void set_cpus_allowed_rt(struct task_struct *p, - const struct cpumask *new_mask) -{ - int weight = cpumask_weight(new_mask); - - BUG_ON(!rt_task(p)); - - /* - * Update the migration status of the RQ if we have an RT task - * which is running AND changing its weight value. - */ - if (p->se.on_rq && (weight != p->rt.nr_cpus_allowed)) { - struct rq *rq = task_rq(p); - - if (!task_current(rq, p)) { - /* - * Make sure we dequeue this task from the pushable list - * before going further. It will either remain off of - * the list because we are no longer pushable, or it - * will be requeued. - */ - if (p->rt.nr_cpus_allowed > 1) - dequeue_pushable_task(rq, p); - - /* - * Requeue if our weight is changing and still > 1 - */ - if (weight > 1) - enqueue_pushable_task(rq, p); - - } - - if ((p->rt.nr_cpus_allowed <= 1) && (weight > 1)) { - rq->rt.rt_nr_migratory++; - } else if ((p->rt.nr_cpus_allowed > 1) && (weight <= 1)) { - BUG_ON(!rq->rt.rt_nr_migratory); - rq->rt.rt_nr_migratory--; - } - - update_rt_migration(&rq->rt); - } - - cpumask_copy(&p->cpus_allowed, new_mask); - p->rt.nr_cpus_allowed = weight; -} - -/* Assumes rq->lock is held */ -static void rq_online_rt(struct rq *rq) -{ - if (rq->rt.overloaded) - rt_set_overload(rq); - - __enable_runtime(rq); - - cpupri_set(&rq->rd->cpupri, rq->cpu, rq->rt.highest_prio.curr); -} - -/* Assumes rq->lock is held */ -static void rq_offline_rt(struct rq *rq) -{ - if (rq->rt.overloaded) - rt_clear_overload(rq); - - __disable_runtime(rq); - - cpupri_set(&rq->rd->cpupri, rq->cpu, CPUPRI_INVALID); -} - -/* - * When switch from the rt queue, we bring ourselves to a position - * that we might want to pull RT tasks from other runqueues. - */ -static void switched_from_rt(struct rq *rq, struct task_struct *p, - int running) -{ - /* - * If there are other RT tasks then we will reschedule - * and the scheduling of the other RT tasks will handle - * the balancing. But if we are the last RT task - * we may need to handle the pulling of RT tasks - * now. - */ - if (!rq->rt.rt_nr_running) - pull_rt_task(rq); -} - -static inline void init_sched_rt_class(void) -{ - unsigned int i; - - for_each_possible_cpu(i) - zalloc_cpumask_var_node(&per_cpu(local_cpu_mask, i), - GFP_KERNEL, cpu_to_node(i)); -} -#endif /* CONFIG_SMP */ - -/* - * When switching a task to RT, we may overload the runqueue - * with RT tasks. In this case we try to push them off to - * other runqueues. - */ -static void switched_to_rt(struct rq *rq, struct task_struct *p, - int running) -{ - int check_resched = 1; - - /* - * If we are already running, then there's nothing - * that needs to be done. But if we are not running - * we may need to preempt the current running task. - * If that current running task is also an RT task - * then see if we can move to another run queue. - */ - if (!running) { -#ifdef CONFIG_SMP - if (rq->rt.overloaded && push_rt_task(rq) && - /* Don't resched if we changed runqueues */ - rq != task_rq(p)) - check_resched = 0; -#endif /* CONFIG_SMP */ - if (check_resched && p->prio < rq->curr->prio) - resched_task(rq->curr); - } -} - -/* - * Priority of the task has changed. This may cause - * us to initiate a push or pull. - */ -static void prio_changed_rt(struct rq *rq, struct task_struct *p, - int oldprio, int running) -{ - if (running) { -#ifdef CONFIG_SMP - /* - * If our priority decreases while running, we - * may need to pull tasks to this runqueue. - */ - if (oldprio < p->prio) - pull_rt_task(rq); - /* - * If there's a higher priority task waiting to run - * then reschedule. Note, the above pull_rt_task - * can release the rq lock and p could migrate. - * Only reschedule if p is still on the same runqueue. - */ - if (p->prio > rq->rt.highest_prio.curr && rq->curr == p) - resched_task(p); -#else - /* For UP simply resched on drop of prio */ - if (oldprio < p->prio) - resched_task(p); -#endif /* CONFIG_SMP */ - } else { - /* - * This task is not running, but if it is - * greater than the current running task - * then reschedule. - */ - if (p->prio < rq->curr->prio) - resched_task(rq->curr); - } -} - -static void watchdog(struct rq *rq, struct task_struct *p) -{ - unsigned long soft, hard; - - if (!p->signal) - return; - - soft = p->signal->rlim[RLIMIT_RTTIME].rlim_cur; - hard = p->signal->rlim[RLIMIT_RTTIME].rlim_max; - - if (soft != RLIM_INFINITY) { - unsigned long next; - - p->rt.timeout++; - next = DIV_ROUND_UP(min(soft, hard), USEC_PER_SEC/HZ); - if (p->rt.timeout > next) - p->cputime_expires.sched_exp = p->se.sum_exec_runtime; - } -} - -static void task_tick_rt(struct rq *rq, struct task_struct *p, int queued) -{ - update_curr_rt(rq); - - watchdog(rq, p); - - /* - * RR tasks need a special form of timeslice management. - * FIFO tasks have no timeslices. - */ - if (p->policy != SCHED_RR) - return; - - if (--p->rt.time_slice) - return; - - p->rt.time_slice = DEF_TIMESLICE; - - /* - * Requeue to the end of queue if we are not the only element - * on the queue: - */ - if (p->rt.run_list.prev != p->rt.run_list.next) { - requeue_task_rt(rq, p, 0); - set_tsk_need_resched(p); - } -} - -static void set_curr_task_rt(struct rq *rq) -{ - struct task_struct *p = rq->curr; - - p->se.exec_start = rq->clock; - - /* The running task is never eligible for pushing */ - dequeue_pushable_task(rq, p); -} - -static const struct sched_class rt_sched_class = { - .next = &fair_sched_class, - .enqueue_task = enqueue_task_rt, - .dequeue_task = dequeue_task_rt, - .yield_task = yield_task_rt, - - .check_preempt_curr = check_preempt_curr_rt, - - .pick_next_task = pick_next_task_rt, - .put_prev_task = put_prev_task_rt, - -#ifdef CONFIG_SMP - .select_task_rq = select_task_rq_rt, - - .load_balance = load_balance_rt, - .move_one_task = move_one_task_rt, - .set_cpus_allowed = set_cpus_allowed_rt, - .rq_online = rq_online_rt, - .rq_offline = rq_offline_rt, - .pre_schedule = pre_schedule_rt, - .needs_post_schedule = needs_post_schedule_rt, - .post_schedule = post_schedule_rt, - .task_wake_up = task_wake_up_rt, - .switched_from = switched_from_rt, -#endif - - .set_curr_task = set_curr_task_rt, - .task_tick = task_tick_rt, - - .prio_changed = prio_changed_rt, - .switched_to = switched_to_rt, -}; - -#ifdef CONFIG_SCHED_DEBUG -extern void print_rt_rq(struct seq_file *m, int cpu, struct rt_rq *rt_rq); - -static void print_rt_stats(struct seq_file *m, int cpu) -{ - struct rt_rq *rt_rq; - - rcu_read_lock(); - for_each_leaf_rt_rq(rt_rq, cpu_rq(cpu)) - print_rt_rq(m, cpu, rt_rq); - rcu_read_unlock(); -} -#endif /* CONFIG_SCHED_DEBUG */ - Index: linux-2.6.30-bfs/kernel/sched_bfs.c =================================================================== --- /dev/null 1970-01-01 00:00:00.000000000 +0000 +++ linux-2.6.30-bfs/kernel/sched_bfs.c 2009-09-06 18:56:58.389602008 +1000 @@ -0,0 +1,5793 @@ +/* + * kernel/sched_bfs.c, was sched.c + * + * Kernel scheduler and related syscalls + * + * Copyright (C) 1991-2002 Linus Torvalds + * + * 1996-12-23 Modified by Dave Grothe to fix bugs in semaphores and + * make semaphores SMP safe + * 1998-11-19 Implemented schedule_timeout() and related stuff + * by Andrea Arcangeli + * 2002-01-04 New ultra-scalable O(1) scheduler by Ingo Molnar: + * hybrid priority-list and round-robin design with + * an array-switch method of distributing timeslices + * and per-CPU runqueues. Cleanups and useful suggestions + * by Davide Libenzi, preemptible kernel bits by Robert Love. + * 2003-09-03 Interactivity tuning by Con Kolivas. + * 2004-04-02 Scheduler domains code by Nick Piggin + * 2007-04-15 Work begun on replacing all interactivity tuning with a + * fair scheduling design by Con Kolivas. + * 2007-05-05 Load balancing (smp-nice) and other improvements + * by Peter Williams + * 2007-05-06 Interactivity improvements to CFS by Mike Galbraith + * 2007-07-01 Group scheduling enhancements by Srivatsa Vaddagiri + * 2007-11-29 RT balancing improvements by Steven Rostedt, Gregory Haskins, + * Thomas Gleixner, Mike Kravetz + * now Brainfuck deadline scheduling policy by Con Kolivas deletes + * a whole lot of those previous things. + */ + +#include <linux/mm.h> +#include <linux/module.h> +#include <linux/nmi.h> +#include <linux/init.h> +#include <asm/uaccess.h> +#include <linux/highmem.h> +#include <linux/smp_lock.h> +#include <asm/mmu_context.h> +#include <linux/interrupt.h> +#include <linux/capability.h> +#include <linux/completion.h> +#include <linux/kernel_stat.h> +#include <linux/debug_locks.h> +#include <linux/security.h> +#include <linux/notifier.h> +#include <linux/profile.h> +#include <linux/freezer.h> +#include <linux/vmalloc.h> +#include <linux/blkdev.h> +#include <linux/delay.h> +#include <linux/smp.h> +#include <linux/threads.h> +#include <linux/timer.h> +#include <linux/rcupdate.h> +#include <linux/cpu.h> +#include <linux/cpuset.h> +#include <linux/cpumask.h> +#include <linux/percpu.h> +#include <linux/kthread.h> +#include <linux/proc_fs.h> +#include <linux/seq_file.h> +#include <linux/syscalls.h> +#include <linux/times.h> +#include <linux/tsacct_kern.h> +#include <linux/kprobes.h> +#include <linux/delayacct.h> +#include <linux/reciprocal_div.h> +#include <linux/log2.h> +#include <linux/ftrace.h> +#include <trace/sched.h> + +#include <asm/tlb.h> +#include <asm/unistd.h> + +#define rt_prio(prio) unlikely((prio) < MAX_RT_PRIO) +#define rt_task(p) rt_prio((p)->prio) +#define batch_task(p) (unlikely((p)->policy == SCHED_BATCH)) +#define is_rt_policy(policy) ((policy) == SCHED_FIFO || \ + (policy) == SCHED_RR) +#define has_rt_policy(p) unlikely(is_rt_policy((p)->policy)) +#define idleprio_task(p) unlikely((p)->policy == SCHED_IDLEPRIO) +#define iso_task(p) unlikely((p)->policy == SCHED_ISO) +#define ISO_PERIOD ((5 * HZ * num_online_cpus()) + 1) + +/* + * Convert user-nice values [ -20 ... 0 ... 19 ] + * to static priority [ MAX_RT_PRIO..MAX_PRIO-1 ], + * and back. + */ +#define NICE_TO_PRIO(nice) (MAX_RT_PRIO + (nice) + 20) +#define PRIO_TO_NICE(prio) ((prio) - MAX_RT_PRIO - 20) +#define TASK_NICE(p) PRIO_TO_NICE((p)->static_prio) + +/* + * 'User priority' is the nice value converted to something we + * can work with better when scaling various scheduler parameters, + * it's a [ 0 ... 39 ] range. + */ +#define USER_PRIO(p) ((p)-MAX_RT_PRIO) +#define TASK_USER_PRIO(p) USER_PRIO((p)->static_prio) +#define MAX_USER_PRIO (USER_PRIO(MAX_PRIO)) +#define SCHED_PRIO(p) ((p)+MAX_RT_PRIO) + +/* Some helpers for converting to/from various scales.*/ +#define JIFFIES_TO_NS(TIME) ((TIME) * (1000000000 / HZ)) +#define MS_TO_NS(TIME) ((TIME) * 1000000) +#define MS_TO_US(TIME) ((TIME) * 1000) + + +DEFINE_TRACE(sched_wait_task); +DEFINE_TRACE(sched_wakeup); +DEFINE_TRACE(sched_wakeup_new); +DEFINE_TRACE(sched_switch); +DEFINE_TRACE(sched_migrate_task); + +#ifdef CONFIG_SMP +/* + * Divide a load by a sched group cpu_power : (load / sg->__cpu_power) + * Since cpu_power is a 'constant', we can use a reciprocal divide. + */ +static inline u32 sg_div_cpu_power(const struct sched_group *sg, u32 load) +{ + return reciprocal_divide(load, sg->reciprocal_cpu_power); +} + +/* + * Each time a sched group cpu_power is changed, + * we must compute its reciprocal value + */ +static inline void sg_inc_cpu_power(struct sched_group *sg, u32 val) +{ + sg->__cpu_power += val; + sg->reciprocal_cpu_power = reciprocal_value(sg->__cpu_power); +} +#endif + +/* + * This is the time all tasks within the same priority round robin. + * Value is in ms and set to a minimum of 6ms. Scales with number of cpus. + * Tunable via /proc interface. + */ +int rr_interval __read_mostly = 6; + +/* + * sched_iso_cpu - sysctl which determines the cpu percentage SCHED_ISO tasks + * are allowed to run five seconds as real time tasks. This is the total over + * all online cpus. + */ +int sched_iso_cpu __read_mostly = 70; + +int prio_ratios[PRIO_RANGE] __read_mostly; + +static inline unsigned long timeslice(void) +{ + return MS_TO_US(rr_interval); +} + +struct global_rq { + spinlock_t lock; + unsigned long nr_running; + unsigned long nr_uninterruptible; + unsigned long long nr_switches; + struct list_head queue[PRIO_LIMIT]; + DECLARE_BITMAP(prio_bitmap, PRIO_LIMIT + 1); + unsigned long iso_ticks; + unsigned short iso_refractory; +#ifdef CONFIG_SMP + cpumask_t cpu_idle_map; +#endif +}; + +static struct global_rq grq; + +/* + * This is the main, per-CPU runqueue data structure. + * All this is protected by the global_rq lock. + */ +struct rq { +#ifdef CONFIG_SMP +#ifdef CONFIG_NO_HZ + unsigned char in_nohz_recently; +#endif +#endif + + struct task_struct *preempt_next; + struct task_struct *curr, *idle; + struct mm_struct *prev_mm; + + unsigned long queued_deadline; + int queued_prio; + + atomic_t nr_iowait; + + int cpu; /* cpu of this runqueue */ + int online; + +#ifdef CONFIG_SMP + struct root_domain *rd; + struct sched_domain *sd; + + struct list_head migration_queue; +#endif + + u64 clock; +#ifdef CONFIG_SCHEDSTATS + + /* latency stats */ + struct sched_info rq_sched_info; + unsigned long long rq_cpu_time; + /* could above be rq->cfs_rq.exec_clock + rq->rt_rq.rt_runtime ? */ + + /* sys_sched_yield() stats */ + unsigned int yld_count; + + /* schedule() stats */ + unsigned int sched_switch; + unsigned int sched_count; + unsigned int sched_goidle; + + /* try_to_wake_up() stats */ + unsigned int ttwu_count; + unsigned int ttwu_local; + + /* BKL stats */ + unsigned int bkl_count; +#endif +}; + +static DEFINE_PER_CPU(struct rq, runqueues) ____cacheline_aligned_in_smp; +static DEFINE_MUTEX(sched_hotcpu_mutex); + +#ifdef CONFIG_SMP + +/* + * We add the notion of a root-domain which will be used to define per-domain + * variables. Each exclusive cpuset essentially defines an island domain by + * fully partitioning the member cpus from any other cpuset. Whenever a new + * exclusive cpuset is created, we also create and attach a new root-domain + * object. + * + */ +struct root_domain { + atomic_t refcount; + cpumask_var_t span; + cpumask_var_t online; + + /* + * The "RT overload" flag: it gets set if a CPU has more than + * one runnable RT task. + */ + cpumask_var_t rto_mask; + atomic_t rto_count; +#if defined(CONFIG_SCHED_MC) || defined(CONFIG_SCHED_SMT) + /* + * Preferred wake up cpu nominated by sched_mc balance that will be + * used when most cpus are idle in the system indicating overall very + * low system utilisation. Triggered at POWERSAVINGS_BALANCE_WAKEUP(2) + */ + unsigned int sched_mc_preferred_wakeup_cpu; +#endif +}; + +/* + * By default the system creates a single root-domain with all cpus as + * members (mimicking the global state we have today). + */ +static struct root_domain def_root_domain; + +#endif + +static inline int cpu_of(struct rq *rq) +{ +#ifdef CONFIG_SMP + return rq->cpu; +#else + return 0; +#endif +} + +/* + * The domain tree (rq->sd) is protected by RCU's quiescent state transition. + * See detach_destroy_domains: synchronize_sched for details. + * + * The domain tree of any CPU may only be accessed from within + * preempt-disabled sections. + */ +#define for_each_domain(cpu, __sd) \ + for (__sd = rcu_dereference(cpu_rq(cpu)->sd); __sd; __sd = __sd->parent) + +#define cpu_rq(cpu) (&per_cpu(runqueues, (cpu))) +#define this_rq() (&__get_cpu_var(runqueues)) +#define task_rq(p) cpu_rq(task_cpu(p)) +#define cpu_curr(cpu) (cpu_rq(cpu)->curr) + +#include "sched_stats.h" + +#ifndef prepare_arch_switch +# define prepare_arch_switch(next) do { } while (0) +#endif +#ifndef finish_arch_switch +# define finish_arch_switch(prev) do { } while (0) +#endif + +static inline void update_rq_clock(struct rq *rq) +{ + rq->clock = sched_clock_cpu(cpu_of(rq)); +} + +static inline int task_running(struct task_struct *p) +{ + return (!!p->oncpu); +} + +static inline void grq_lock(void) + __acquires(grq.lock) +{ + spin_lock(&grq.lock); +} + +static inline void grq_unlock(void) + __releases(grq.lock) +{ + spin_unlock(&grq.lock); +} + +static inline void grq_lock_irq(void) + __acquires(grq.lock) +{ + spin_lock_irq(&grq.lock); +} + +static inline void time_lock_rq(struct rq *rq) + __acquires(grq.lock) +{ + grq_lock(); + update_rq_clock(rq); +} + +static inline void grq_unlock_irq(void) + __releases(grq.lock) +{ + spin_unlock_irq(&grq.lock); +} + +static inline void grq_lock_irqsave(unsigned long *flags) + __acquires(grq.lock) +{ + local_irq_save(*flags); + spin_lock(&grq.lock); +} + +static inline void grq_unlock_irqrestore(unsigned long *flags) + __releases(grq.lock) +{ + spin_unlock(&grq.lock); + local_irq_restore(*flags); +} + +static inline struct rq +*task_grq_lock(struct task_struct *p, unsigned long *flags) + __acquires(grq.lock) +{ + grq_lock_irqsave(flags); + return task_rq(p); +} + +static inline struct rq +*time_task_grq_lock(struct task_struct *p, unsigned long *flags) + __acquires(grq.lock) +{ + struct rq *rq; + + grq_lock_irqsave(flags); + rq = task_rq(p); + update_rq_clock(rq); + return rq; +} + +static inline void task_grq_unlock(unsigned long *flags) + __releases(grq.lock) +{ + grq_unlock_irqrestore(flags); +} + +/** + * grunqueue_is_locked + * + * Returns true if the global runqueue is locked. + * This interface allows printk to be called with the runqueue lock + * held and know whether or not it is OK to wake up the klogd. + */ +int grunqueue_is_locked(void) +{ + return spin_is_locked(&grq.lock); +} + +void grq_unlock_wait(void) + __releases(grq.lock) +{ + smp_mb(); /* spin-unlock-wait is not a full memory barrier */ + spin_unlock_wait(&grq.lock); +} + +static inline void time_grq_lock(struct rq *rq, unsigned long *flags) + __acquires(grq.lock) +{ + local_irq_save(*flags); + time_lock_rq(rq); +} + +static inline struct rq *__task_grq_lock(struct task_struct *p) + __acquires(grq.lock) +{ + grq_lock(); + return task_rq(p); +} + +static inline void __task_grq_unlock(void) + __releases(grq.lock) +{ + grq_unlock(); +} + +#ifndef __ARCH_WANT_UNLOCKED_CTXSW +static inline void prepare_lock_switch(struct rq *rq, struct task_struct *next) +{ +} + +static inline void finish_lock_switch(struct rq *rq, struct task_struct *prev) +{ +#ifdef CONFIG_DEBUG_SPINLOCK + /* this is a valid case when another task releases the spinlock */ + grq.lock.owner = current; +#endif + /* + * If we are tracking spinlock dependencies then we have to + * fix up the runqueue lock - which gets 'carried over' from + * prev into current: + */ + spin_acquire(&grq.lock.dep_map, 0, 0, _THIS_IP_); + + grq_unlock_irq(); +} + +#else /* __ARCH_WANT_UNLOCKED_CTXSW */ + +static inline void prepare_lock_switch(struct rq *rq, struct task_struct *next) +{ +#ifdef __ARCH_WANT_INTERRUPTS_ON_CTXSW + grq_unlock_irq(); +#else + grq_unlock(); +#endif +} + +static inline void finish_lock_switch(struct rq *rq, struct task_struct *prev) +{ + smp_wmb(); +#ifndef __ARCH_WANT_INTERRUPTS_ON_CTXSW + local_irq_enable(); +#endif +} +#endif /* __ARCH_WANT_UNLOCKED_CTXSW */ + +/* + * A task that is queued will be on the grq run list. + * A task that is not running or queued will not be on the grq run list. + * A task that is currently running will have ->oncpu set. + * The only time a task will be both queued and running by these definitions + * is during schedule, and all under grq_lock so it should never be seen. + */ + +static inline int task_queued(struct task_struct *p) +{ + return (!list_empty(&p->run_list)); +} + +static inline int queued_or_running(struct task_struct *p) +{ + return (task_queued(p) || task_running(p)); +} + +/* + * Removing from the global runqueue. Enter with grq locked. + */ +static void dequeue_task(struct task_struct *p) +{ + list_del_init(&p->run_list); + if (list_empty(grq.queue + p->prio)) + __clear_bit(p->prio, grq.prio_bitmap); +} + +static inline void reset_first_time_slice(struct task_struct *p) +{ + if (unlikely(p->first_time_slice)) + p->first_time_slice = 0; +} + +static int idleprio_suitable(struct task_struct *p) +{ + return (!freezing(p) && !signal_pending(p) && + !(task_contributes_to_load(p)) && !(p->flags & (PF_EXITING))); +} + +static int isoprio_suitable(void) +{ + return !grq.iso_refractory; +} + +/* + * Adding to the global runqueue. Enter with grq locked. + */ +static inline void enqueue_task(struct task_struct *p) +{ + if (idleprio_task(p) && !rt_task(p)) { + if (idleprio_suitable(p)) + p->prio = p->normal_prio; + else + p->prio = NORMAL_PRIO; + } + + if (iso_task(p) && !rt_task(p)) { + if (isoprio_suitable()) + p->prio = p->normal_prio; + else + p->prio = NORMAL_PRIO; + } + __set_bit(p->prio, grq.prio_bitmap); + list_add_tail(&p->run_list, grq.queue + p->prio); + sched_info_queued(p); +} + +/* Only idle task does this as a real time task*/ +static inline void enqueue_task_head(struct task_struct *p) +{ + __set_bit(p->prio, grq.prio_bitmap); + list_add(&p->run_list, grq.queue + p->prio); + sched_info_queued(p); +} + +static inline void requeue_task(struct task_struct *p) +{ + sched_info_queued(p); +} + +static inline int prio_ratio(struct task_struct *p) +{ + return prio_ratios[USER_PRIO(p->static_prio)]; +} + +/* + * task_timeslice - all tasks of all priorities get the exact same timeslice + * length. CPU distribution is handled by giving different deadlines to + * tasks of different priorities. + */ +static int task_timeslice(struct task_struct *p) +{ + return (rr_interval * prio_ratio(p) / 100); +} + +/* + * activate_idle_task - move idle task to the _front_ of runqueue. + */ +static inline void activate_idle_task(struct task_struct *p) +{ + enqueue_task_head(p); + grq.nr_running++; +} + +static inline int normal_prio(struct task_struct *p) +{ + if (has_rt_policy(p)) + return MAX_RT_PRIO - 1 - p->rt_priority; + if (idleprio_task(p)) + return IDLE_PRIO; + if (iso_task(p)) + return ISO_PRIO; + return NORMAL_PRIO; +} + +/* + * Calculate the current priority, i.e. the priority + * taken into account by the scheduler. This value might + * be boosted by RT tasks as it will be RT if the task got + * RT-boosted. If not then it returns p->normal_prio. + */ +static int effective_prio(struct task_struct *p) +{ + p->normal_prio = normal_prio(p); + /* + * If we are RT tasks or we were boosted to RT priority, + * keep the priority unchanged. Otherwise, update priority + * to the normal priority: + */ + if (!rt_prio(p->prio)) + return p->normal_prio; + return p->prio; +} + +/* + * activate_task - move a task to the runqueue. Enter with grq locked. The rq + * doesn't really matter but gives us the local clock. + */ +static void activate_task(struct task_struct *p, struct rq *rq) +{ + u64 now = rq->clock; + + /* + * Sleep time is in units of nanosecs, so shift by 20 to get a + * milliseconds-range estimation of the amount of time that the task + * spent sleeping: + */ + if (unlikely(prof_on == SLEEP_PROFILING)) { + if (p->state == TASK_UNINTERRUPTIBLE) + profile_hits(SLEEP_PROFILING, (void *)get_wchan(p), + (now - p->timestamp) >> 20); + } + + p->prio = effective_prio(p); + p->timestamp = now; + if (task_contributes_to_load(p)) + grq.nr_uninterruptible--; + enqueue_task(p); + grq.nr_running++; +} + +/* + * deactivate_task - If it's running, it's not on the grq and we can just + * decrement the nr_running. Otherwise we have to dequeue it. Enter with grq + * locked. + */ +static inline void deactivate_task(struct task_struct *p) +{ + if (task_contributes_to_load(p)) + grq.nr_uninterruptible++; + grq.nr_running--; +} + +#ifdef CONFIG_SMP +void set_task_cpu(struct task_struct *p, unsigned int cpu) +{ + trace_sched_migrate_task(p, task_cpu(p), cpu); + /* + * After ->cpu is set up to a new value, task_grq_lock(p, ...) can be + * successfuly executed on another CPU. We must ensure that updates of + * per-task data have been completed by this moment. + */ + smp_wmb(); + task_thread_info(p)->cpu = cpu; +} +#endif + +/* + * Move a task off the global queue and take it to a cpu for it will + * become the running task. + */ +static inline void take_task(struct rq *rq, struct task_struct *p) +{ + set_task_cpu(p, rq->cpu); + dequeue_task(p); +} + +/* + * Returns a descheduling task to the grq runqueue unless it is being + * deactivated. + */ +static inline void return_task(struct task_struct *p, int deactivate) +{ + if (deactivate) + deactivate_task(p); + else + enqueue_task(p); +} + +/* + * resched_task - mark a task 'to be rescheduled now'. + * + * On UP this means the setting of the need_resched flag, on SMP it + * might also involve a cross-CPU call to trigger the scheduler on + * the target CPU. + */ +#ifdef CONFIG_SMP + +#ifndef tsk_is_polling +#define tsk_is_polling(t) test_tsk_thread_flag(t, TIF_POLLING_NRFLAG) +#endif + +static void resched_task(struct task_struct *p) +{ + int cpu; + + assert_spin_locked(&grq.lock); + + if (unlikely(test_tsk_thread_flag(p, TIF_NEED_RESCHED))) + return; + + set_tsk_thread_flag(p, TIF_NEED_RESCHED); + + cpu = task_cpu(p); + if (cpu == smp_processor_id()) + return; + + /* NEED_RESCHED must be visible before we test polling */ + smp_mb(); + if (!tsk_is_polling(p)) + smp_send_reschedule(cpu); +} + +#else +static inline void resched_task(struct task_struct *p) +{ + assert_spin_locked(&grq.lock); + set_tsk_need_resched(p); +} +#endif + +/** + * task_curr - is this task currently executing on a CPU? + * @p: the task in question. + */ +inline int task_curr(const struct task_struct *p) +{ + return cpu_curr(task_cpu(p)) == p; +} + +#ifdef CONFIG_SMP +struct migration_req { + struct list_head list; + + struct task_struct *task; + int dest_cpu; + + struct completion done; +}; + +/* + * wait_task_inactive - wait for a thread to unschedule. + * + * If @match_state is nonzero, it's the @p->state value just checked and + * not expected to change. If it changes, i.e. @p might have woken up, + * then return zero. When we succeed in waiting for @p to be off its CPU, + * we return a positive number (its total switch count). If a second call + * a short while later returns the same number, the caller can be sure that + * @p has remained unscheduled the whole time. + * + * The caller must ensure that the task *will* unschedule sometime soon, + * else this function might spin for a *long* time. This function can't + * be called with interrupts off, or it may introduce deadlock with + * smp_call_function() if an IPI is sent by the same process we are + * waiting to become inactive. + */ +unsigned long wait_task_inactive(struct task_struct *p, long match_state) +{ + unsigned long flags; + int running, on_rq; + unsigned long ncsw; + struct rq *rq; + + for (;;) { + /* + * We do the initial early heuristics without holding + * any task-queue locks at all. We'll only try to get + * the runqueue lock when things look like they will + * work out! + */ + rq = task_rq(p); + + /* + * If the task is actively running on another CPU + * still, just relax and busy-wait without holding + * any locks. + * + * NOTE! Since we don't hold any locks, it's not + * even sure that "rq" stays as the right runqueue! + * But we don't care, since "task_running()" will + * return false if the runqueue has changed and p + * is actually now running somewhere else! + */ + while (task_running(p)) { + if (match_state && unlikely(p->state != match_state)) + return 0; + cpu_relax(); + } + + /* + * Ok, time to look more closely! We need the rq + * lock now, to be *sure*. If we're wrong, we'll + * just go back and repeat. + */ + rq = task_grq_lock(p, &flags); + trace_sched_wait_task(rq, p); + running = task_running(p); + on_rq = task_queued(p); + ncsw = 0; + if (!match_state || p->state == match_state) + ncsw = p->nvcsw | LONG_MIN; /* sets MSB */ + task_grq_unlock(&flags); + + /* + * If it changed from the expected state, bail out now. + */ + if (unlikely(!ncsw)) + break; + + /* + * Was it really running after all now that we + * checked with the proper locks actually held? + * + * Oops. Go back and try again.. + */ + if (unlikely(running)) { + cpu_relax(); + continue; + } + + /* + * It's not enough that it's not actively running, + * it must be off the runqueue _entirely_, and not + * preempted! + * + * So if it was still runnable (but just not actively + * running right now), it's preempted, and we should + * yield - it could be a while. + */ + if (unlikely(on_rq)) { + schedule_timeout_uninterruptible(1); + continue; + } + + /* + * Ahh, all good. It wasn't running, and it wasn't + * runnable, which means that it will never become + * running in the future either. We're all done! + */ + break; + } + + return ncsw; +} + +/*** + * kick_process - kick a running thread to enter/exit the kernel + * @p: the to-be-kicked thread + * + * Cause a process which is running on another CPU to enter + * kernel-mode, without any delay. (to get signals handled.) + * + * NOTE: this function doesnt have to take the runqueue lock, + * because all it wants to ensure is that the remote task enters + * the kernel. If the IPI races and the task has been migrated + * to another CPU then no harm is done and the purpose has been + * achieved as well. + */ +void kick_process(struct task_struct *p) +{ + int cpu; + + preempt_disable(); + cpu = task_cpu(p); + if ((cpu != smp_processor_id()) && task_curr(p)) + smp_send_reschedule(cpu); + preempt_enable(); +} + +#endif + +/* + * We need to have a special definition for an idle runqueue when testing + * for preemption on CONFIG_HOTPLUG_CPU as the idle task may be scheduled as + * a realtime task in sched_idle_next. + */ +#ifdef CONFIG_HOTPLUG_CPU +#define rq_idle(rq) ((rq)->curr == (rq)->idle && !rt_task((rq)->curr)) +#else +#define rq_idle(rq) ((rq)->curr == (rq)->idle) +#endif + +/* + * RT tasks preempt purely on priority. SCHED_NORMAL tasks preempt on the + * basis of earlier deadlines. SCHED_BATCH and SCHED_IDLEPRIO don't preempt, + * they cooperatively multitask. + */ +static inline int task_preempts_curr(struct task_struct *p, struct rq *rq) +{ + struct task_struct *curr = rq->curr; + int preempts = 0; + + if (p->prio < curr->prio) + preempts = 1; + else if (p->policy == SCHED_NORMAL && (p->prio == curr->prio && + p->deadline < rq->queued_deadline)) + preempts = 1; + return preempts; +} + +/* + * Wake up *any* suitable cpu to schedule this task. + */ +static void try_preempt(struct task_struct *p, struct rq *this_rq) +{ + unsigned long latest_deadline, cpu; + struct rq *lowest_prio_rq; + int lowest_prio; + cpumask_t tmp; + + if (cpu_isset(this_rq->cpu, p->cpus_allowed) && rq_idle(this_rq)) { + /* this_rq is idle, use that. */ + lowest_prio_rq = this_rq; + goto found_rq; + } + + /* Use this_rq as baseline and fall back on */ + latest_deadline = this_rq->queued_deadline; + lowest_prio = this_rq->queued_prio; + lowest_prio_rq = this_rq; + + cpus_and(tmp, cpu_online_map, p->cpus_allowed); + for_each_cpu_mask(cpu, tmp) { + unsigned long queued_deadline; + int queued_prio; + struct rq *rq; + + rq = cpu_rq(cpu); + + if (rq_idle(rq)) { + /* found an idle rq, use that one */ + lowest_prio_rq = rq; + goto found_rq; + } + + queued_prio = rq->queued_prio; + queued_deadline = rq->queued_deadline; + if (queued_prio < lowest_prio || + (queued_prio == lowest_prio && + queued_deadline > latest_deadline)) { + lowest_prio = queued_prio; + latest_deadline = queued_deadline; + lowest_prio_rq = rq; + } + } + + if (!task_preempts_curr(p, lowest_prio_rq)) + return; +found_rq: + resched_task(lowest_prio_rq->curr); + lowest_prio_rq->preempt_next = p; + return; +} + +/*** + * try_to_wake_up - wake up a thread + * @p: the to-be-woken-up thread + * @state: the mask of task states that can be woken + * sync is ignored on bfs + * + * Put it on the run-queue if it's not already there. The "current" + * thread is always on the run-queue (except when the actual + * re-schedule is in progress), and as such you're allowed to do + * the simpler "current->state = TASK_RUNNING" to mark yourself + * runnable without the overhead of this. + * + * returns failure only if the task is already active. + */ +static int try_to_wake_up(struct task_struct *p, unsigned int state) +{ + unsigned long flags; + int success = 0; + long old_state; + struct rq *rq; + + rq = time_task_grq_lock(p, &flags); + old_state = p->state; + if (!(old_state & state)) + goto out_unlock; + + if (queued_or_running(p)) + goto out_running; + + activate_task(p, rq); + try_preempt(p, rq); + success = 1; + +out_running: + trace_sched_wakeup(rq, p, success); + p->state = TASK_RUNNING; +out_unlock: + task_grq_unlock(&flags); + return success; +} + +int wake_up_process(struct task_struct *p) +{ + return try_to_wake_up(p, TASK_ALL); +} +EXPORT_SYMBOL(wake_up_process); + +int wake_up_state(struct task_struct *p, unsigned int state) +{ + return try_to_wake_up(p, state); +} + +/* + * Perform scheduler related setup for a newly forked process p. + * p is forked by current. + */ +void sched_fork(struct task_struct *p, int clone_flags) +{ + int cpu = get_cpu(); + +#ifdef CONFIG_PREEMPT_NOTIFIERS + INIT_HLIST_HEAD(&p->preempt_notifiers); +#endif + /* + * We mark the process as running here, but have not actually + * inserted it onto the runqueue yet. This guarantees that + * nobody will actually run it, and a signal or other external + * event cannot wake it up and insert it on the runqueue either. + */ + p->state = TASK_RUNNING; + set_task_cpu(p, cpu); + p->sched_time = 0; + + /* + * Make sure we do not leak PI boosting priority to the child: + */ + p->prio = current->normal_prio; + + INIT_LIST_HEAD(&p->run_list); +#if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT) + if (unlikely(sched_info_on())) + memset(&p->sched_info, 0, sizeof(p->sched_info)); +#endif + + p->oncpu = 0; + +#ifdef CONFIG_PREEMPT + /* Want to start with kernel preemption disabled. */ + task_thread_info(p)->preempt_count = 1; +#endif + if (unlikely(p->policy == SCHED_FIFO)) + goto out; + /* + * Share the timeslice between parent and child, thus the + * total amount of pending timeslices in the system doesn't change, + * resulting in more scheduling fairness. + */ + local_irq_disable(); + if (current->time_slice > 0) { + current->time_slice /= 2; + if (current->time_slice) + p->time_slice = current->time_slice; + else + p->time_slice = 1; + /* + * The remainder of the first timeslice might be recovered by + * the parent if the child exits early enough. + */ + p->first_time_slice = 1; + } else + p->time_slice = 0; + + local_irq_enable(); +out: + put_cpu(); +} + +#ifdef CONFIG_SMP +static int no_idle_cpus(void) +{ + return (cpus_empty(grq.cpu_idle_map)); +} +#else +static int no_idle_cpus(void) +{ + return 1; +} +#endif + +/* + * wake_up_new_task - wake up a newly created task for the first time. + * + * This function will do some initial scheduler statistics housekeeping + * that must be done for every newly created context, then puts the task + * on the runqueue and wakes it. + */ +void wake_up_new_task(struct task_struct *p, unsigned long clone_flags) +{ + struct task_struct *parent; + unsigned long flags; + struct rq *rq = time_task_grq_lock(p, &flags); + + parent = p->parent; + BUG_ON(p->state != TASK_RUNNING); + set_task_cpu(p, task_cpu(parent)); + + activate_task(p, rq); + trace_sched_wakeup_new(rq, p, 1); + if (!(clone_flags & CLONE_VM) && rq->curr == parent && + no_idle_cpus()) { + /* + * The VM isn't cloned, so we're in a good position to + * do child-runs-first in anticipation of an exec. This + * usually avoids a lot of COW overhead. + */ + set_tsk_need_resched(parent); + rq->preempt_next = p; + } else + try_preempt(p, rq); + task_grq_unlock(&flags); +} + +/* + * Potentially available exiting-child timeslices are + * retrieved here - this way the parent does not get + * penalized for creating too many threads. + * + * (this cannot be used to 'generate' timeslices + * artificially, because any timeslice recovered here + * was given away by the parent in the first place.) + */ +void sched_exit(struct task_struct *p) +{ + struct task_struct *parent; + unsigned long flags; + struct rq *rq; + + parent = p->parent; + rq = task_grq_lock(parent, &flags); + if (p->first_time_slice > 0 && task_cpu(p) == task_cpu(parent)) { + parent->time_slice += p->time_slice; + if (unlikely(parent->time_slice > timeslice())) + parent->time_slice = timeslice(); + } + task_grq_unlock(&flags); +} + +#ifdef CONFIG_PREEMPT_NOTIFIERS + +/** + * preempt_notifier_register - tell me when current is being preempted & rescheduled + * @notifier: notifier struct to register + */ +void preempt_notifier_register(struct preempt_notifier *notifier) +{ + hlist_add_head(¬ifier->link, ¤t->preempt_notifiers); +} +EXPORT_SYMBOL_GPL(preempt_notifier_register); + +/** + * preempt_notifier_unregister - no longer interested in preemption notifications + * @notifier: notifier struct to unregister + * + * This is safe to call from within a preemption notifier. + */ +void preempt_notifier_unregister(struct preempt_notifier *notifier) +{ + hlist_del(¬ifier->link); +} +EXPORT_SYMBOL_GPL(preempt_notifier_unregister); + +static void fire_sched_in_preempt_notifiers(struct task_struct *curr) +{ + struct preempt_notifier *notifier; + struct hlist_node *node; + + hlist_for_each_entry(notifier, node, &curr->preempt_notifiers, link) + notifier->ops->sched_in(notifier, raw_smp_processor_id()); +} + +static void +fire_sched_out_preempt_notifiers(struct task_struct *curr, + struct task_struct *next) +{ + struct preempt_notifier *notifier; + struct hlist_node *node; + + hlist_for_each_entry(notifier, node, &curr->preempt_notifiers, link) + notifier->ops->sched_out(notifier, next); +} + +#else /* !CONFIG_PREEMPT_NOTIFIERS */ + +static void fire_sched_in_preempt_notifiers(struct task_struct *curr) +{ +} + +static void +fire_sched_out_preempt_notifiers(struct task_struct *curr, + struct task_struct *next) +{ +} + +#endif /* CONFIG_PREEMPT_NOTIFIERS */ + +/** + * prepare_task_switch - prepare to switch tasks + * @rq: the runqueue preparing to switch + * @next: the task we are going to switch to. + * + * This is called with the rq lock held and interrupts off. It must + * be paired with a subsequent finish_task_switch after the context + * switch. + * + * prepare_task_switch sets up locking and calls architecture specific + * hooks. + */ +static inline void +prepare_task_switch(struct rq *rq, struct task_struct *prev, + struct task_struct *next) +{ + fire_sched_out_preempt_notifiers(prev, next); + prepare_lock_switch(rq, next); + prepare_arch_switch(next); +} + +/** + * finish_task_switch - clean up after a task-switch + * @rq: runqueue associated with task-switch + * @prev: the thread we just switched away from. + * + * finish_task_switch must be called after the context switch, paired + * with a prepare_task_switch call before the context switch. + * finish_task_switch will reconcile locking set up by prepare_task_switch, + * and do any other architecture-specific cleanup actions. + * + * Note that we may have delayed dropping an mm in context_switch(). If + * so, we finish that here outside of the runqueue lock. (Doing it + * with the lock held can cause deadlocks; see schedule() for + * details.) + */ +static inline void finish_task_switch(struct rq *rq, struct task_struct *prev) + __releases(grq.lock) +{ + struct mm_struct *mm = rq->prev_mm; + long prev_state; + + rq->prev_mm = NULL; + + /* + * A task struct has one reference for the use as "current". + * If a task dies, then it sets TASK_DEAD in tsk->state and calls + * schedule one last time. The schedule call will never return, and + * the scheduled task must drop that reference. + * The test for TASK_DEAD must occur while the runqueue locks are + * still held, otherwise prev could be scheduled on another cpu, die + * there before we look at prev->state, and then the reference would + * be dropped twice. + * Manfred Spraul <manfred@colorfullife.com> + */ + prev_state = prev->state; + finish_arch_switch(prev); + finish_lock_switch(rq, prev); + + fire_sched_in_preempt_notifiers(current); + if (mm) + mmdrop(mm); + if (unlikely(prev_state == TASK_DEAD)) { + /* + * Remove function-return probe instances associated with this + * task and put them back on the free list. + */ + kprobe_flush_task(prev); + put_task_struct(prev); + } +} + +/** + * schedule_tail - first thing a freshly forked thread must call. + * @prev: the thread we just switched away from. + */ +asmlinkage void schedule_tail(struct task_struct *prev) + __releases(grq.lock) +{ + struct rq *rq = this_rq(); + + finish_task_switch(rq, prev); +#ifdef __ARCH_WANT_UNLOCKED_CTXSW + /* In this case, finish_task_switch does not reenable preemption */ + preempt_enable(); +#endif + if (current->set_child_tid) + put_user(current->pid, current->set_child_tid); +} + +/* + * context_switch - switch to the new MM and the new + * thread's register state. + */ +static inline void +context_switch(struct rq *rq, struct task_struct *prev, + struct task_struct *next) +{ + struct mm_struct *mm, *oldmm; + + prepare_task_switch(rq, prev, next); + trace_sched_switch(rq, prev, next); + mm = next->mm; + oldmm = prev->active_mm; + /* + * For paravirt, this is coupled with an exit in switch_to to + * combine the page table reload and the switch backend into + * one hypercall. + */ + arch_enter_lazy_cpu_mode(); + + if (unlikely(!mm)) { + next->active_mm = oldmm; + atomic_inc(&oldmm->mm_count); + enter_lazy_tlb(oldmm, next); + } else + switch_mm(oldmm, mm, next); + + if (unlikely(!prev->mm)) { + prev->active_mm = NULL; + rq->prev_mm = oldmm; + } + /* + * Since the runqueue lock will be released by the next + * task (which is an invalid locking op but in the case + * of the scheduler it's an obvious special-case), so we + * do an early lockdep release here: + */ +#ifndef __ARCH_WANT_UNLOCKED_CTXSW + spin_release(&grq.lock.dep_map, 1, _THIS_IP_); +#endif + + /* Here we just switch the register state and the stack. */ + switch_to(prev, next, prev); + + barrier(); + /* + * this_rq must be evaluated again because prev may have moved + * CPUs since it called schedule(), thus the 'rq' on its stack + * frame will be invalid. + */ + finish_task_switch(this_rq(), prev); +} + +/* + * nr_running, nr_uninterruptible and nr_context_switches: + * + * externally visible scheduler statistics: current number of runnable + * threads, current number of uninterruptible-sleeping threads, total + * number of context switches performed since bootup. + */ +unsigned long nr_running(void) +{ + return grq.nr_running; +} + +unsigned long nr_uninterruptible(void) +{ + return grq.nr_uninterruptible; +} + +unsigned long long nr_context_switches(void) +{ + return grq.nr_switches; +} + +unsigned long nr_iowait(void) +{ + unsigned long i, sum = 0; + + for_each_possible_cpu(i) + sum += atomic_read(&cpu_rq(i)->nr_iowait); + + return sum; +} + +unsigned long nr_active(void) +{ + return nr_running() + nr_uninterruptible(); +} + +DEFINE_PER_CPU(struct kernel_stat, kstat); + +EXPORT_PER_CPU_SYMBOL(kstat); + +/* + * This is called on clock ticks and on context switches. + * Bank in p->sched_time the ns elapsed since the last tick or switch. + * CPU scheduler quota accounting is also performed here in microseconds. + * The value returned from sched_clock() occasionally gives bogus values so + * some sanity checking is required. Time is supposed to be banked all the + * time so default to half a tick to make up for when sched_clock reverts + * to just returning jiffies, and for hardware that can't do tsc. + */ +static void +update_cpu_clock(struct task_struct *p, struct rq *rq, int tick) +{ + long time_diff = rq->clock - p->last_ran; + + if (tick) { + /* + * Called from scheduler_tick() there should be less than two + * jiffies worth, and not negative/overflow. + */ + if (time_diff > JIFFIES_TO_NS(2)) + time_diff = JIFFIES_TO_NS(2); + else if (time_diff <= 0) + time_diff = JIFFIES_TO_NS(1) / 2; + } else { + /* + * Called from context_switch there should be less than one + * jiffy worth, and not negative/overflow. + */ + if (time_diff > JIFFIES_TO_NS(1)) + time_diff = JIFFIES_TO_NS(1); + else if (time_diff <= 0) + time_diff = JIFFIES_TO_NS(1) / 2; + } + /* time_slice accounting is done in usecs to avoid overflow on 32bit */ + if (p != rq->idle && p->policy != SCHED_FIFO) + p->time_slice -= time_diff / 1000; + p->sched_time += time_diff; + p->last_ran = rq->clock; +} + +/* + * Return any ns on the sched_clock that have not yet been accounted in + * @p in case that task is currently running. + * + * Called with task_grq_lock() held on @rq. + */ +static u64 do_task_delta_exec(struct task_struct *p, struct rq *rq) +{ + u64 ns = 0; + + if (p == rq->curr) { + update_rq_clock(rq); + ns = rq->clock - p->last_ran; + if ((s64)ns < 0) + ns = 0; + } + + return ns; +} + +unsigned long long task_delta_exec(struct task_struct *p) +{ + unsigned long flags; + struct rq *rq; + u64 ns = 0; + + rq = task_grq_lock(p, &flags); + ns = do_task_delta_exec(p, rq); + task_grq_unlock(&flags); + + return ns; +} + +/* + * Return accounted runtime for the task. + * In case the task is currently running, return the runtime plus current's + * pending runtime that have not been accounted yet. + */ +unsigned long long task_sched_runtime(struct task_struct *p) +{ + unsigned long flags; + struct rq *rq; + u64 ns = 0; + + rq = task_grq_lock(p, &flags); + ns = p->sched_time + do_task_delta_exec(p, rq); + task_grq_unlock(&flags); + + return ns; +} + +/* + * Return sum_exec_runtime for the thread group. + * In case the task is currently running, return the sum plus current's + * pending runtime that have not been accounted yet. + * + * Note that the thread group might have other running tasks as well, + * so the return value not includes other pending runtime that other + * running tasks might have. + */ +unsigned long long thread_group_sched_runtime(struct task_struct *p) +{ + struct task_cputime totals; + unsigned long flags; + struct rq *rq; + u64 ns; + + rq = task_grq_lock(p, &flags); + thread_group_cputime(p, &totals); + ns = totals.sum_exec_runtime + do_task_delta_exec(p, rq); + task_grq_unlock(&flags); + + return ns; +} + +/* + * Account user cpu time to a process. + * @p: the process that the cpu time gets accounted to + * @cputime: the cpu time spent in user space since the last update + * @cputime_scaled: cputime scaled by cpu frequency + */ +void account_user_time(struct task_struct *p, cputime_t cputime, + cputime_t cputime_scaled) +{ + struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat; + cputime64_t tmp; + + /* Add user time to process. */ + p->utime = cputime_add(p->utime, cputime); + p->utimescaled = cputime_add(p->utimescaled, cputime_scaled); + account_group_user_time(p, cputime); + + /* Add user time to cpustat. */ + tmp = cputime_to_cputime64(cputime); + if (TASK_NICE(p) > 0) + cpustat->nice = cputime64_add(cpustat->nice, tmp); + else + cpustat->user = cputime64_add(cpustat->user, tmp); + + //cpuacct_update_stats(p, CPUACCT_STAT_USER, cputime); + /* Account for user time used */ + acct_update_integrals(p); +} + +/* + * Account guest cpu time to a process. + * @p: the process that the cpu time gets accounted to + * @cputime: the cpu time spent in virtual machine since the last update + * @cputime_scaled: cputime scaled by cpu frequency + */ +static void account_guest_time(struct task_struct *p, cputime_t cputime, + cputime_t cputime_scaled) +{ + cputime64_t tmp; + struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat; + + tmp = cputime_to_cputime64(cputime); + + /* Add guest time to process. */ + p->utime = cputime_add(p->utime, cputime); + p->utimescaled = cputime_add(p->utimescaled, cputime_scaled); + account_group_user_time(p, cputime); + p->gtime = cputime_add(p->gtime, cputime); + + /* Add guest time to cpustat. */ + cpustat->user = cputime64_add(cpustat->user, tmp); + cpustat->guest = cputime64_add(cpustat->guest, tmp); +} + +/* + * Account system cpu time to a process. + * @p: the process that the cpu time gets accounted to + * @hardirq_offset: the offset to subtract from hardirq_count() + * @cputime: the cpu time spent in kernel space since the last update + * @cputime_scaled: cputime scaled by cpu frequency + */ +void account_system_time(struct task_struct *p, int hardirq_offset, + cputime_t cputime, cputime_t cputime_scaled) +{ + struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat; + cputime64_t tmp; + + if ((p->flags & PF_VCPU) && (irq_count() - hardirq_offset == 0)) { + account_guest_time(p, cputime, cputime_scaled); + return; + } + + /* Add system time to process. */ + p->stime = cputime_add(p->stime, cputime); + p->stimescaled = cputime_add(p->stimescaled, cputime_scaled); + account_group_system_time(p, cputime); + + /* Add system time to cpustat. */ + tmp = cputime_to_cputime64(cputime); + if (hardirq_count() - hardirq_offset) + cpustat->irq = cputime64_add(cpustat->irq, tmp); + else if (softirq_count()) + cpustat->softirq = cputime64_add(cpustat->softirq, tmp); + else + cpustat->system = cputime64_add(cpustat->system, tmp); + + //cpuacct_update_stats(p, CPUACCT_STAT_SYSTEM, cputime); + + /* Account for system time used */ + acct_update_integrals(p); +} + +/* + * Account for involuntary wait time. + * @steal: the cpu time spent in involuntary wait + */ +void account_steal_time(cputime_t cputime) +{ + struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat; + cputime64_t cputime64 = cputime_to_cputime64(cputime); + + cpustat->steal = cputime64_add(cpustat->steal, cputime64); +} + +/* + * Account for idle time. + * @cputime: the cpu time spent in idle wait + */ +void account_idle_time(cputime_t cputime) +{ + struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat; + cputime64_t cputime64 = cputime_to_cputime64(cputime); + struct rq *rq = this_rq(); + + if (atomic_read(&rq->nr_iowait) > 0) + cpustat->iowait = cputime64_add(cpustat->iowait, cputime64); + else + cpustat->idle = cputime64_add(cpustat->idle, cputime64); +} + +#ifndef CONFIG_VIRT_CPU_ACCOUNTING + +/* + * Account a single tick of cpu time. + * @p: the process that the cpu time gets accounted to + * @user_tick: indicates if the tick is a user or a system tick + */ +void account_process_tick(struct task_struct *p, int user_tick) +{ + cputime_t one_jiffy = jiffies_to_cputime(1); + cputime_t one_jiffy_scaled = cputime_to_scaled(one_jiffy); + struct rq *rq = this_rq(); + + if (user_tick) + account_user_time(p, one_jiffy, one_jiffy_scaled); + else if ((p != rq->idle) || (irq_count() != HARDIRQ_OFFSET)) + account_system_time(p, HARDIRQ_OFFSET, one_jiffy, + one_jiffy_scaled); + else + account_idle_time(one_jiffy); +} + +/* + * Account multiple ticks of steal time. + * @p: the process from which the cpu time has been stolen + * @ticks: number of stolen ticks + */ +void account_steal_ticks(unsigned long ticks) +{ + account_steal_time(jiffies_to_cputime(ticks)); +} + +/* + * Account multiple ticks of idle time. + * @ticks: number of stolen ticks + */ +void account_idle_ticks(unsigned long ticks) +{ + account_idle_time(jiffies_to_cputime(ticks)); +} +#endif + +/* + * Test if SCHED_ISO tasks have run longer than their alloted period as RT + * tasks and set the refractory flag if necessary. There is 10% hysteresis + * for unsetting the flag. + */ +static unsigned int test_ret_isorefractory(struct rq *rq) +{ + if (likely(!grq.iso_refractory)) { + if (grq.iso_ticks / ISO_PERIOD > sched_iso_cpu) + grq.iso_refractory = 1; + } else { + if (grq.iso_ticks / ISO_PERIOD < (sched_iso_cpu * 90 / 100)) + grq.iso_refractory = 0; + } + return grq.iso_refractory; +} + +/* No SCHED_ISO task was running so decrease rq->iso_ticks */ +static inline void no_iso_tick(void) +{ + grq.iso_ticks = grq.iso_ticks * (ISO_PERIOD - 1) / ISO_PERIOD; +} + +static int task_running_iso(struct task_struct *p) +{ + return p->prio == ISO_PRIO; +} + +/* This manages tasks that have run out of timeslice during a scheduler_tick */ +static void task_running_tick(struct rq *rq, struct task_struct *p) +{ + /* + * If a SCHED_ISO task is running we increment the iso_ticks. In + * order to prevent SCHED_ISO tasks from causing starvation in the + * presence of true RT tasks we account those as iso_ticks as well. + */ + if ((rt_task(p) || (iso_task(p) && !grq.iso_refractory))) { + if (grq.iso_ticks <= (ISO_PERIOD * 100) - 100) + grq.iso_ticks += 100; + } else + no_iso_tick(); + + if (iso_task(p)) { + if (unlikely(test_ret_isorefractory(rq))) { + if (task_running_iso(p)) { + /* + * SCHED_ISO task is running as RT and limit + * has been hit. Force it to reschedule as + * SCHED_NORMAL by zeroing its time_slice + */ + p->time_slice = 0; + } + } + } + + /* SCHED_FIFO tasks never run out of timeslice. */ + if (p->time_slice > 0 || p->policy == SCHED_FIFO) + return; + + /* p->time_slice <= 0 */ + if (likely(task_running(p))) { + requeue_task(p); + set_tsk_need_resched(p); + } +} + +/* + * This function gets called by the timer code, with HZ frequency. + * We call it with interrupts disabled. + */ +void scheduler_tick(void) +{ + int cpu = smp_processor_id(); + struct rq *rq = cpu_rq(cpu); + struct task_struct *p; + + sched_clock_tick(); + time_lock_rq(rq); + p = rq->curr; + update_cpu_clock(p, rq, 1); + if (!rq_idle(rq)) + task_running_tick(rq, p); + else + no_iso_tick(); + grq_unlock(); +} + +notrace unsigned long get_parent_ip(unsigned long addr) +{ + if (in_lock_functions(addr)) { + addr = CALLER_ADDR2; + if (in_lock_functions(addr)) + addr = CALLER_ADDR3; + } + return addr; +} + +#if defined(CONFIG_PREEMPT) && (defined(CONFIG_DEBUG_PREEMPT) || \ + defined(CONFIG_PREEMPT_TRACER)) +void __kprobes add_preempt_count(int val) +{ +#ifdef CONFIG_DEBUG_PREEMPT + /* + * Underflow? + */ + if (DEBUG_LOCKS_WARN_ON((preempt_count() < 0))) + return; +#endif + preempt_count() += val; +#ifdef CONFIG_DEBUG_PREEMPT + /* + * Spinlock count overflowing soon? + */ + DEBUG_LOCKS_WARN_ON((preempt_count() & PREEMPT_MASK) >= + PREEMPT_MASK - 10); +#endif + if (preempt_count() == val) + trace_preempt_off(CALLER_ADDR0, get_parent_ip(CALLER_ADDR1)); +} +EXPORT_SYMBOL(add_preempt_count); + +void __kprobes sub_preempt_count(int val) +{ +#ifdef CONFIG_DEBUG_PREEMPT + /* + * Underflow? + */ + if (DEBUG_LOCKS_WARN_ON(val > preempt_count())) + return; + /* + * Is the spinlock portion underflowing? + */ + if (DEBUG_LOCKS_WARN_ON((val < PREEMPT_MASK) && + !(preempt_count() & PREEMPT_MASK))) + return; +#endif + + if (preempt_count() == val) + trace_preempt_on(CALLER_ADDR0, get_parent_ip(CALLER_ADDR1)); + preempt_count() -= val; +} +EXPORT_SYMBOL(sub_preempt_count); +#endif + +/* + * Deadline is "now" in jiffies + (offset by priority). Setting the deadline + * is the key to everything. It distributes cpu fairly amongst tasks of the + * same nice value, it proportions cpu according to nice level, it means the + * task that last woke up the longest ago has the earliest deadline, thus + * ensuring that interactive tasks get low latency on wake up. + */ +static inline unsigned long prio_deadline_diff(struct task_struct *p) +{ + return (prio_ratio(p) * rr_interval * HZ / 1000 / 100) ? : 1; +} + +static inline int longest_deadline(void) +{ + return (prio_ratios[39] * rr_interval * HZ / 1000 / 100); +} + +/* + * SCHED_IDLEPRIO tasks still have a deadline set, but offset by to nice +19. + * This allows nice levels to work between IDLEPRIO tasks and gives a + * deadline longer than nice +19 for when they're scheduled as SCHED_NORMAL + * tasks. + */ +static inline void time_slice_expired(struct task_struct *p) +{ + reset_first_time_slice(p); + p->time_slice = timeslice(); + p->deadline = jiffies + prio_deadline_diff(p); + if (idleprio_task(p)) + p->deadline += longest_deadline(); +} + +static inline void check_deadline(struct task_struct *p) +{ + if (p->time_slice <= 0) + time_slice_expired(p); +} + +/* + * O(n) lookup of all tasks in the global runqueue. The real brainfuck + * of lock contention and O(n). + */ +static inline struct +task_struct *earliest_deadline_task(struct rq *rq, struct task_struct *idle) +{ + unsigned long long_deadline, shortest_deadline; + struct task_struct *edt, *p; + unsigned int cpu = rq->cpu; + struct list_head *queue; + int idx = 0; + + if (rq->preempt_next) { + if (likely(task_queued(rq->preempt_next) && + cpu_isset(cpu, rq->preempt_next->cpus_allowed))) { + edt = rq->preempt_next; + goto out_take; + } + } +retry: + idx = find_next_bit(grq.prio_bitmap, PRIO_LIMIT, idx); + queue = &grq.queue[idx]; + if (idx < MAX_RT_PRIO) { + /* We found rt tasks */ + list_for_each_entry(p, queue, run_list) { + if (cpu_isset(cpu, p->cpus_allowed)) { + edt = p; + goto out_take; + } + } + /* More rt tasks, we couldn't take the lower prio ones */ + ++idx; + goto retry; + } + + /* No rt tasks, find earliest deadline task */ + edt = idle; + if (unlikely(idx >= PRIO_LIMIT)) { + /* All rt tasks but none suitable for this cpu */ + goto out; + } + + long_deadline = shortest_deadline = longest_deadline() * 2 + 1; + list_for_each_entry(p, queue, run_list) { + unsigned long deadline_diff; + /* Make sure cpu affinity is ok */ + if (!cpu_isset(cpu, p->cpus_allowed)) + continue; + + deadline_diff = p->deadline - jiffies; + + /* Normalise all old deadlines and cope with jiffy wrap. */ + if (deadline_diff > long_deadline) + deadline_diff = 0; + + /* Select the earliest deadline task now */ + if (edt == idle || deadline_diff < shortest_deadline) { + shortest_deadline = deadline_diff; + edt = p; + } + } + if (edt == idle) { + if (idx < IDLE_PRIO) { + /* Haven't checked for SCHED_IDLEPRIO tasks yet */ + idx++; + goto retry; + } + goto out; + } +out_take: + take_task(rq, edt); +out: + return edt; +} + +#ifdef CONFIG_SMP +static inline void set_cpuidle_map(unsigned long cpu) +{ + cpu_set(cpu, grq.cpu_idle_map); +} + +static inline void clear_cpuidle_map(unsigned long cpu) +{ + cpu_clear(cpu, grq.cpu_idle_map); +} + +#else /* CONFIG_SMP */ +static inline void set_cpuidle_map(unsigned long cpu) +{ +} + +static inline void clear_cpuidle_map(unsigned long cpu) +{ +} +#endif /* !CONFIG_SMP */ + +/* + * Print scheduling while atomic bug: + */ +static noinline void __schedule_bug(struct task_struct *prev) +{ + struct pt_regs *regs = get_irq_regs(); + + printk(KERN_ERR "BUG: scheduling while atomic: %s/%d/0x%08x\n", + prev->comm, prev->pid, preempt_count()); + + debug_show_held_locks(prev); + print_modules(); + if (irqs_disabled()) + print_irqtrace_events(prev); + + if (regs) + show_regs(regs); + else + dump_stack(); +} + +/* + * Various schedule()-time debugging checks and statistics: + */ +static inline void schedule_debug(struct task_struct *prev) +{ + /* + * Test if we are atomic. Since do_exit() needs to call into + * schedule() atomically, we ignore that path for now. + * Otherwise, whine if we are scheduling when we should not be. + */ + if (unlikely(in_atomic_preempt_off() && !prev->exit_state)) + __schedule_bug(prev); + + profile_hit(SCHED_PROFILING, __builtin_return_address(0)); + + schedstat_inc(this_rq(), sched_count); +#ifdef CONFIG_SCHEDSTATS + if (unlikely(prev->lock_depth >= 0)) { + schedstat_inc(this_rq(), bkl_count); + schedstat_inc(prev, sched_info.bkl_count); + } +#endif +} + +/* + * schedule() is the main scheduler function. + */ +asmlinkage void __sched __schedule(void) +{ + struct task_struct *prev, *next, *idle; + int deactivate = 0, cpu; + long *switch_count; + struct rq *rq; + u64 now; + + cpu = smp_processor_id(); + rq = this_rq(); + rcu_qsctr_inc(cpu); + prev = rq->curr; + switch_count = &prev->nivcsw; + + release_kernel_lock(prev); +need_resched_nonpreemptible: + + schedule_debug(prev); + idle = rq->idle; + /* + * The idle thread is not allowed to schedule! + * Remove this check after it has been exercised a bit. + */ + if (unlikely(prev == idle) && prev->state != TASK_RUNNING) { + printk(KERN_ERR "bad: scheduling from the idle thread!\n"); + dump_stack(); + } + + grq_lock_irq(); + update_rq_clock(rq); + now = rq->clock; + + clear_tsk_need_resched(prev); + + if (prev->state && !(preempt_count() & PREEMPT_ACTIVE)) { + if (unlikely(signal_pending_state(prev->state, prev))) + prev->state = TASK_RUNNING; + else + deactivate = 1; + switch_count = &prev->nvcsw; + } + + if (prev != idle) { + check_deadline(prev); + return_task(prev, deactivate); + } + + if (likely(grq.nr_running)) { + next = earliest_deadline_task(rq, idle); + rq->queued_deadline = next->deadline; + } else { + next = idle; + schedstat_inc(rq, sched_goidle); + } + + if (next == rq->idle) + set_cpuidle_map(cpu); + else + clear_cpuidle_map(cpu); + + rq->preempt_next = NULL; + + prefetch(next); + prefetch_stack(next); + + update_cpu_clock(prev, rq, 0); + prev->timestamp = prev->last_ran = now; + rq->queued_prio = next->prio; + + if (likely(prev != next)) { + sched_info_switch(prev, next); + grq.nr_switches++; + next->oncpu = 1; + prev->oncpu = 0; + rq->curr = next; + ++*switch_count; + + context_switch(rq, prev, next); /* unlocks the rq */ + /* + * the context switch might have flipped the stack from under + * us, hence refresh the local variables. + */ + cpu = smp_processor_id(); + rq = cpu_rq(cpu); + } else + grq_unlock_irq(); + + if (unlikely(reacquire_kernel_lock(current) < 0)) + goto need_resched_nonpreemptible; +} + +asmlinkage void __sched schedule(void) +{ +need_resched: + preempt_disable(); + __schedule(); + preempt_enable_no_resched(); + if (unlikely(test_thread_flag(TIF_NEED_RESCHED))) + goto need_resched; +} +EXPORT_SYMBOL(schedule); + +#ifdef CONFIG_SMP +int mutex_spin_on_owner(struct mutex *lock, struct thread_info *owner) +{ + return 0; +} +#endif + +#ifdef CONFIG_PREEMPT +/* + * this is the entry point to schedule() from in-kernel preemption + * off of preempt_enable. Kernel preemptions off return from interrupt + * occur there and call schedule directly. + */ +asmlinkage void __sched preempt_schedule(void) +{ + struct thread_info *ti = current_thread_info(); + + /* + * If there is a non-zero preempt_count or interrupts are disabled, + * we do not want to preempt the current task. Just return.. + */ + if (likely(ti->preempt_count || irqs_disabled())) + return; + + do { + add_preempt_count(PREEMPT_ACTIVE); + schedule(); + sub_preempt_count(PREEMPT_ACTIVE); + + /* + * Check again in case we missed a preemption opportunity + * between schedule and now. + */ + barrier(); + } while (need_resched()); +} +EXPORT_SYMBOL(preempt_schedule); + +/* + * this is the entry point to schedule() from kernel preemption + * off of irq context. + * Note, that this is called and return with irqs disabled. This will + * protect us against recursive calling from irq. + */ +asmlinkage void __sched preempt_schedule_irq(void) +{ + struct thread_info *ti = current_thread_info(); + + /* Catch callers which need to be fixed */ + BUG_ON(ti->preempt_count || !irqs_disabled()); + + do { + add_preempt_count(PREEMPT_ACTIVE); + local_irq_enable(); + schedule(); + local_irq_disable(); + sub_preempt_count(PREEMPT_ACTIVE); + + /* + * Check again in case we missed a preemption opportunity + * between schedule and now. + */ + barrier(); + } while (need_resched()); +} + +#endif /* CONFIG_PREEMPT */ + +int default_wake_function(wait_queue_t *curr, unsigned mode, int sync, + void *key) +{ + return try_to_wake_up(curr->private, mode); +} +EXPORT_SYMBOL(default_wake_function); + +/* + * The core wakeup function. Non-exclusive wakeups (nr_exclusive == 0) just + * wake everything up. If it's an exclusive wakeup (nr_exclusive == small +ve + * number) then we wake all the non-exclusive tasks and one exclusive task. + * + * There are circumstances in which we can try to wake a task which has already + * started to run but is not in state TASK_RUNNING. try_to_wake_up() returns + * zero in this (rare) case, and we handle it by continuing to scan the queue. + */ +void __wake_up_common(wait_queue_head_t *q, unsigned int mode, + int nr_exclusive, int sync, void *key) +{ + struct list_head *tmp, *next; + + list_for_each_safe(tmp, next, &q->task_list) { + wait_queue_t *curr = list_entry(tmp, wait_queue_t, task_list); + unsigned flags = curr->flags; + + if (curr->func(curr, mode, sync, key) && + (flags & WQ_FLAG_EXCLUSIVE) && !--nr_exclusive) + break; + } +} + +/** + * __wake_up - wake up threads blocked on a waitqueue. + * @q: the waitqueue + * @mode: which threads + * @nr_exclusive: how many wake-one or wake-many threads to wake up + * @key: is directly passed to the wakeup function + */ +void __wake_up(wait_queue_head_t *q, unsigned int mode, + int nr_exclusive, void *key) +{ + unsigned long flags; + + spin_lock_irqsave(&q->lock, flags); + __wake_up_common(q, mode, nr_exclusive, 0, key); + spin_unlock_irqrestore(&q->lock, flags); +} +EXPORT_SYMBOL(__wake_up); + +/* + * Same as __wake_up but called with the spinlock in wait_queue_head_t held. + */ +void __wake_up_locked(wait_queue_head_t *q, unsigned int mode) +{ + __wake_up_common(q, mode, 1, 0, NULL); +} + +void __wake_up_locked_key(wait_queue_head_t *q, unsigned int mode, void *key) +{ + __wake_up_common(q, mode, 1, 0, key); +} + +/** + * __wake_up_sync_key - wake up threads blocked on a waitqueue. + * @q: the waitqueue + * @mode: which threads + * @nr_exclusive: how many wake-one or wake-many threads to wake up + * @key: opaque value to be passed to wakeup targets + * + * The sync wakeup differs that the waker knows that it will schedule + * away soon, so while the target thread will be woken up, it will not + * be migrated to another CPU - ie. the two threads are 'synchronized' + * with each other. This can prevent needless bouncing between CPUs. + * + * On UP it can prevent extra preemption. + */ +void __wake_up_sync_key(wait_queue_head_t *q, unsigned int mode, + int nr_exclusive, void *key) +{ + unsigned long flags; + int sync = 1; + + if (unlikely(!q)) + return; + + if (unlikely(!nr_exclusive)) + sync = 0; + + spin_lock_irqsave(&q->lock, flags); + __wake_up_common(q, mode, nr_exclusive, sync, key); + spin_unlock_irqrestore(&q->lock, flags); +} +EXPORT_SYMBOL_GPL(__wake_up_sync_key); + +/** + * __wake_up_sync - wake up threads blocked on a waitqueue. + * @q: the waitqueue + * @mode: which threads + * @nr_exclusive: how many wake-one or wake-many threads to wake up + * + * The sync wakeup differs that the waker knows that it will schedule + * away soon, so while the target thread will be woken up, it will not + * be migrated to another CPU - ie. the two threads are 'synchronized' + * with each other. This can prevent needless bouncing between CPUs. + * + * On UP it can prevent extra preemption. + */ +void __wake_up_sync(wait_queue_head_t *q, unsigned int mode, int nr_exclusive) +{ + unsigned long flags; + int sync = 1; + + if (unlikely(!q)) + return; + + if (unlikely(!nr_exclusive)) + sync = 0; + + spin_lock_irqsave(&q->lock, flags); + __wake_up_common(q, mode, nr_exclusive, sync, NULL); + spin_unlock_irqrestore(&q->lock, flags); +} +EXPORT_SYMBOL_GPL(__wake_up_sync); /* For internal use only */ + +/** + * complete: - signals a single thread waiting on this completion + * @x: holds the state of this particular completion + * + * This will wake up a single thread waiting on this completion. Threads will be + * awakened in the same order in which they were queued. + * + * See also complete_all(), wait_for_completion() and related routines. + */ +void complete(struct completion *x) +{ + unsigned long flags; + + spin_lock_irqsave(&x->wait.lock, flags); + x->done++; + __wake_up_common(&x->wait, TASK_NORMAL, 1, 0, NULL); + spin_unlock_irqrestore(&x->wait.lock, flags); +} +EXPORT_SYMBOL(complete); + +/** + * complete_all: - signals all threads waiting on this completion + * @x: holds the state of this particular completion + * + * This will wake up all threads waiting on this particular completion event. + */ +void complete_all(struct completion *x) +{ + unsigned long flags; + + spin_lock_irqsave(&x->wait.lock, flags); + x->done += UINT_MAX/2; + __wake_up_common(&x->wait, TASK_NORMAL, 0, 0, NULL); + spin_unlock_irqrestore(&x->wait.lock, flags); +} +EXPORT_SYMBOL(complete_all); + +static inline long __sched +do_wait_for_common(struct completion *x, long timeout, int state) +{ + if (!x->done) { + DECLARE_WAITQUEUE(wait, current); + + wait.flags |= WQ_FLAG_EXCLUSIVE; + __add_wait_queue_tail(&x->wait, &wait); + do { + if (signal_pending_state(state, current)) { + timeout = -ERESTARTSYS; + break; + } + __set_current_state(state); + spin_unlock_irq(&x->wait.lock); + timeout = schedule_timeout(timeout); + spin_lock_irq(&x->wait.lock); + } while (!x->done && timeout); + __remove_wait_queue(&x->wait, &wait); + if (!x->done) + return timeout; + } + x->done--; + return timeout ?: 1; +} + +static long __sched +wait_for_common(struct completion *x, long timeout, int state) +{ + might_sleep(); + + spin_lock_irq(&x->wait.lock); + timeout = do_wait_for_common(x, timeout, state); + spin_unlock_irq(&x->wait.lock); + return timeout; +} + +/** + * wait_for_completion: - waits for completion of a task + * @x: holds the state of this particular completion + * + * This waits to be signaled for completion of a specific task. It is NOT + * interruptible and there is no timeout. + * + * See also similar routines (i.e. wait_for_completion_timeout()) with timeout + * and interrupt capability. Also see complete(). + */ +void __sched wait_for_completion(struct completion *x) +{ + wait_for_common(x, MAX_SCHEDULE_TIMEOUT, TASK_UNINTERRUPTIBLE); +} +EXPORT_SYMBOL(wait_for_completion); + +/** + * wait_for_completion_timeout: - waits for completion of a task (w/timeout) + * @x: holds the state of this particular completion + * @timeout: timeout value in jiffies + * + * This waits for either a completion of a specific task to be signaled or for a + * specified timeout to expire. The timeout is in jiffies. It is not + * interruptible. + */ +unsigned long __sched +wait_for_completion_timeout(struct completion *x, unsigned long timeout) +{ + return wait_for_common(x, timeout, TASK_UNINTERRUPTIBLE); +} +EXPORT_SYMBOL(wait_for_completion_timeout); + +/** + * wait_for_completion_interruptible: - waits for completion of a task (w/intr) + * @x: holds the state of this particular completion + * + * This waits for completion of a specific task to be signaled. It is + * interruptible. + */ +int __sched wait_for_completion_interruptible(struct completion *x) +{ + long t = wait_for_common(x, MAX_SCHEDULE_TIMEOUT, TASK_INTERRUPTIBLE); + if (t == -ERESTARTSYS) + return t; + return 0; +} +EXPORT_SYMBOL(wait_for_completion_interruptible); + +/** + * wait_for_completion_interruptible_timeout: - waits for completion (w/(to,intr)) + * @x: holds the state of this particular completion + * @timeout: timeout value in jiffies + * + * This waits for either a completion of a specific task to be signaled or for a + * specified timeout to expire. It is interruptible. The timeout is in jiffies. + */ +unsigned long __sched +wait_for_completion_interruptible_timeout(struct completion *x, + unsigned long timeout) +{ + return wait_for_common(x, timeout, TASK_INTERRUPTIBLE); +} +EXPORT_SYMBOL(wait_for_completion_interruptible_timeout); + +/** + * wait_for_completion_killable: - waits for completion of a task (killable) + * @x: holds the state of this particular completion + * + * This waits to be signaled for completion of a specific task. It can be + * interrupted by a kill signal. + */ +int __sched wait_for_completion_killable(struct completion *x) +{ + long t = wait_for_common(x, MAX_SCHEDULE_TIMEOUT, TASK_KILLABLE); + if (t == -ERESTARTSYS) + return t; + return 0; +} +EXPORT_SYMBOL(wait_for_completion_killable); + +/** + * try_wait_for_completion - try to decrement a completion without blocking + * @x: completion structure + * + * Returns: 0 if a decrement cannot be done without blocking + * 1 if a decrement succeeded. + * + * If a completion is being used as a counting completion, + * attempt to decrement the counter without blocking. This + * enables us to avoid waiting if the resource the completion + * is protecting is not available. + */ +bool try_wait_for_completion(struct completion *x) +{ + int ret = 1; + + spin_lock_irq(&x->wait.lock); + if (!x->done) + ret = 0; + else + x->done--; + spin_unlock_irq(&x->wait.lock); + return ret; +} +EXPORT_SYMBOL(try_wait_for_completion); + +/** + * completion_done - Test to see if a completion has any waiters + * @x: completion structure + * + * Returns: 0 if there are waiters (wait_for_completion() in progress) + * 1 if there are no waiters. + * + */ +bool completion_done(struct completion *x) +{ + int ret = 1; + + spin_lock_irq(&x->wait.lock); + if (!x->done) + ret = 0; + spin_unlock_irq(&x->wait.lock); + return ret; +} +EXPORT_SYMBOL(completion_done); + +static long __sched +sleep_on_common(wait_queue_head_t *q, int state, long timeout) +{ + unsigned long flags; + wait_queue_t wait; + + init_waitqueue_entry(&wait, current); + + __set_current_state(state); + + spin_lock_irqsave(&q->lock, flags); + __add_wait_queue(q, &wait); + spin_unlock(&q->lock); + timeout = schedule_timeout(timeout); + spin_lock_irq(&q->lock); + __remove_wait_queue(q, &wait); + spin_unlock_irqrestore(&q->lock, flags); + + return timeout; +} + +void __sched interruptible_sleep_on(wait_queue_head_t *q) +{ + sleep_on_common(q, TASK_INTERRUPTIBLE, MAX_SCHEDULE_TIMEOUT); +} +EXPORT_SYMBOL(interruptible_sleep_on); + +long __sched +interruptible_sleep_on_timeout(wait_queue_head_t *q, long timeout) +{ + return sleep_on_common(q, TASK_INTERRUPTIBLE, timeout); +} +EXPORT_SYMBOL(interruptible_sleep_on_timeout); + +void __sched sleep_on(wait_queue_head_t *q) +{ + sleep_on_common(q, TASK_UNINTERRUPTIBLE, MAX_SCHEDULE_TIMEOUT); +} +EXPORT_SYMBOL(sleep_on); + +long __sched sleep_on_timeout(wait_queue_head_t *q, long timeout) +{ + return sleep_on_common(q, TASK_UNINTERRUPTIBLE, timeout); +} +EXPORT_SYMBOL(sleep_on_timeout); + +#ifdef CONFIG_RT_MUTEXES + +/* + * rt_mutex_setprio - set the current priority of a task + * @p: task + * @prio: prio value (kernel-internal form) + * + * This function changes the 'effective' priority of a task. It does + * not touch ->normal_prio like __setscheduler(). + * + * Used by the rt_mutex code to implement priority inheritance logic. + */ +void rt_mutex_setprio(struct task_struct *p, int prio) +{ + unsigned long flags; + int queued, oldprio; + struct rq *rq; + + BUG_ON(prio < 0 || prio > MAX_PRIO); + + rq = time_task_grq_lock(p, &flags); + + oldprio = p->prio; + queued = task_queued(p); + if (queued) + dequeue_task(p); + p->prio = prio; + if (task_running(p)) + resched_task(p); + if (queued) { + enqueue_task(p); + try_preempt(p, rq); + } + + /* + * Reschedule if we are currently running on this runqueue and + * our priority decreased, or if we are not currently running on + * this runqueue and our priority is higher than the current's + */ + if (task_running(p) && p->prio > oldprio) + resched_task(p); + task_grq_unlock(&flags); +} + +#endif + +/* + * Adjust the deadline for when the priority is to change, before it's + * changed. + */ +static void adjust_deadline(struct task_struct *p, int new_prio) +{ + p->deadline += prio_ratios[USER_PRIO(new_prio)] - prio_ratio(p); +} + +void set_user_nice(struct task_struct *p, long nice) +{ + int queued, delta, new_static; + unsigned long flags; + struct rq *rq; + + if (TASK_NICE(p) == nice || nice < -20 || nice > 19) + return; + /* + * We have to be careful, if called from sys_setpriority(), + * the task might be in the middle of scheduling on another CPU. + */ + rq = time_task_grq_lock(p, &flags); + /* + * The RT priorities are set via sched_setscheduler(), but we still + * allow the 'normal' nice value to be set - but as expected + * it wont have any effect on scheduling until the task is + * not SCHED_NORMAL/SCHED_BATCH: + */ + if (has_rt_policy(p)) { + p->static_prio = NICE_TO_PRIO(nice); + goto out_unlock; + } + queued = task_queued(p); + /* + * If p is actually running, we don't need to do anything when + * changing the priority because the grq is unaffected. + */ + if (queued) + dequeue_task(p); + + new_static = NICE_TO_PRIO(nice); + delta = new_static - p->static_prio; + adjust_deadline(p, new_static); + p->static_prio = new_static; + p->prio = effective_prio(p); + + if (queued) { + enqueue_task(p); + try_preempt(p, rq); + } + + /* Just resched the task, schedule() will know what to do. */ + if (task_running(p)) + resched_task(p); +out_unlock: + task_grq_unlock(&flags); +} +EXPORT_SYMBOL(set_user_nice); + +/* + * can_nice - check if a task can reduce its nice value + * @p: task + * @nice: nice value + */ +int can_nice(const struct task_struct *p, const int nice) +{ + /* convert nice value [19,-20] to rlimit style value [1,40] */ + int nice_rlim = 20 - nice; + + return (nice_rlim <= p->signal->rlim[RLIMIT_NICE].rlim_cur || + capable(CAP_SYS_NICE)); +} + +#ifdef __ARCH_WANT_SYS_NICE + +/* + * sys_nice - change the priority of the current process. + * @increment: priority increment + * + * sys_setpriority is a more generic, but much slower function that + * does similar things. + */ +SYSCALL_DEFINE1(nice, int, increment) +{ + long nice, retval; + + /* + * Setpriority might change our priority at the same moment. + * We don't have to worry. Conceptually one call occurs first + * and we have a single winner. + */ + if (increment < -40) + increment = -40; + if (increment > 40) + increment = 40; + + nice = PRIO_TO_NICE(current->static_prio) + increment; + if (nice < -20) + nice = -20; + if (nice > 19) + nice = 19; + + if (increment < 0 && !can_nice(current, nice)) + return -EPERM; + + retval = security_task_setnice(current, nice); + if (retval) + return retval; + + set_user_nice(current, nice); + return 0; +} + +#endif + +/** + * task_prio - return the priority value of a given task. + * @p: the task in question. + * + * This is the priority value as seen by users in /proc. + * RT tasks are offset by -100. Normal tasks are centered + * around 1, value goes from 0 to +80. + */ +int task_prio(const struct task_struct *p) +{ + int delta, prio = p->prio - MAX_RT_PRIO; + + /* rt tasks and iso tasks */ + if (prio <= 0) + goto out; + + /* 225 is a fudge to end up giving +80 for lowest possible prio */ + delta = (p->deadline - jiffies) * 225 / prio_ratios[39]; + if (delta > 0 && delta <= 80) + prio += delta; +out: + return prio; +} + +/** + * task_nice - return the nice value of a given task. + * @p: the task in question. + */ +int task_nice(const struct task_struct *p) +{ + return TASK_NICE(p); +} +EXPORT_SYMBOL_GPL(task_nice); + +/** + * idle_cpu - is a given cpu idle currently? + * @cpu: the processor in question. + */ +int idle_cpu(int cpu) +{ + return cpu_curr(cpu) == cpu_rq(cpu)->idle; +} + +/** + * idle_task - return the idle task for a given cpu. + * @cpu: the processor in question. + */ +struct task_struct *idle_task(int cpu) +{ + return cpu_rq(cpu)->idle; +} + +/** + * find_process_by_pid - find a process with a matching PID value. + * @pid: the pid in question. + */ +static inline struct task_struct *find_process_by_pid(pid_t pid) +{ + return pid ? find_task_by_vpid(pid) : current; +} + +/* Actually do priority change: must hold grq lock. */ +static void __setscheduler(struct task_struct *p, int policy, int prio) +{ + BUG_ON(task_queued(p)); + + p->policy = policy; + p->rt_priority = prio; + p->normal_prio = normal_prio(p); + /* we are holding p->pi_lock already */ + p->prio = rt_mutex_getprio(p); + /* + * Reschedule if running. schedule() will know if it can continue + * running or not. + */ + if (task_running(p)) + resched_task(p); +} + +/* + * check the target process has a UID that matches the current process's + */ +static bool check_same_owner(struct task_struct *p) +{ + const struct cred *cred = current_cred(), *pcred; + bool match; + + rcu_read_lock(); + pcred = __task_cred(p); + match = (cred->euid == pcred->euid || + cred->euid == pcred->uid); + rcu_read_unlock(); + return match; +} + +static int __sched_setscheduler(struct task_struct *p, int policy, + struct sched_param *param, bool user) +{ + struct sched_param zero_param = { .sched_priority = 0 }; + int queued, retval, oldprio, oldpolicy = -1; + unsigned long flags, rlim_rtprio = 0; + struct rq *rq; + + /* may grab non-irq protected spin_locks */ + BUG_ON(in_interrupt()); + + if (is_rt_policy(policy) && !capable(CAP_SYS_NICE)) { + unsigned long lflags; + + if (!lock_task_sighand(p, &lflags)) + return -ESRCH; + rlim_rtprio = p->signal->rlim[RLIMIT_RTPRIO].rlim_cur; + unlock_task_sighand(p, &lflags); + if (rlim_rtprio) + goto recheck; + /* + * If the caller requested an RT policy without having the + * necessary rights, we downgrade the policy to SCHED_ISO. + * We also set the parameter to zero to pass the checks. + */ + policy = SCHED_ISO; + param = &zero_param; + } +recheck: + /* double check policy once rq lock held */ + if (policy < 0) + policy = oldpolicy = p->policy; + else if (!SCHED_RANGE(policy)) + return -EINVAL; + /* + * Valid priorities for SCHED_FIFO and SCHED_RR are + * 1..MAX_USER_RT_PRIO-1, valid priority for SCHED_NORMAL and + * SCHED_BATCH is 0. + */ + if (param->sched_priority < 0 || + (p->mm && param->sched_priority > MAX_USER_RT_PRIO-1) || + (!p->mm && param->sched_priority > MAX_RT_PRIO-1)) + return -EINVAL; + if (is_rt_policy(policy) != (param->sched_priority != 0)) + return -EINVAL; + + /* + * Allow unprivileged RT tasks to decrease priority: + */ + if (user && !capable(CAP_SYS_NICE)) { + if (is_rt_policy(policy)) { + /* can't set/change the rt policy */ + if (policy != p->policy && !rlim_rtprio) + return -EPERM; + + /* can't increase priority */ + if (param->sched_priority > p->rt_priority && + param->sched_priority > rlim_rtprio) + return -EPERM; + } else { + switch (p->policy) { + /* + * Can only downgrade policies but not back to + * SCHED_NORMAL + */ + case SCHED_ISO: + if (policy == SCHED_ISO) + goto out; + if (policy == SCHED_NORMAL) + return -EPERM; + break; + case SCHED_BATCH: + if (policy == SCHED_BATCH) + goto out; + if (policy != SCHED_IDLEPRIO) + return -EPERM; + break; + case SCHED_IDLEPRIO: + if (policy == SCHED_IDLEPRIO) + goto out; + return -EPERM; + default: + break; + } + } + + /* can't change other user's priorities */ + if (!check_same_owner(p)) + return -EPERM; + } + + retval = security_task_setscheduler(p, policy, param); + if (retval) + return retval; + /* + * make sure no PI-waiters arrive (or leave) while we are + * changing the priority of the task: + */ + spin_lock_irqsave(&p->pi_lock, flags); + /* + * To be able to change p->policy safely, the apropriate + * runqueue lock must be held. + */ + rq = __task_grq_lock(p); + /* recheck policy now with rq lock held */ + if (unlikely(oldpolicy != -1 && oldpolicy != p->policy)) { + __task_grq_unlock(); + spin_unlock_irqrestore(&p->pi_lock, flags); + policy = oldpolicy = -1; + goto recheck; + } + update_rq_clock(rq); + queued = task_queued(p); + if (queued) + dequeue_task(p); + oldprio = p->prio; + __setscheduler(p, policy, param->sched_priority); + if (task_running(p)) + resched_task(p); + if (queued) { + enqueue_task(p); + try_preempt(p, rq); + } + __task_grq_unlock(); + spin_unlock_irqrestore(&p->pi_lock, flags); + + rt_mutex_adjust_pi(p); +out: + return 0; +} + +/** + * sched_setscheduler - change the scheduling policy and/or RT priority of a thread. + * @p: the task in question. + * @policy: new policy. + * @param: structure containing the new RT priority. + * + * NOTE that the task may be already dead. + */ +int sched_setscheduler(struct task_struct *p, int policy, + struct sched_param *param) +{ + return __sched_setscheduler(p, policy, param, true); +} + +EXPORT_SYMBOL_GPL(sched_setscheduler); + +/** + * sched_setscheduler_nocheck - change the scheduling policy and/or RT priority of a thread from kernelspace. + * @p: the task in question. + * @policy: new policy. + * @param: structure containing the new RT priority. + * + * Just like sched_setscheduler, only don't bother checking if the + * current context has permission. For example, this is needed in + * stop_machine(): we create temporary high priority worker threads, + * but our caller might not have that capability. + */ +int sched_setscheduler_nocheck(struct task_struct *p, int policy, + struct sched_param *param) +{ + return __sched_setscheduler(p, policy, param, false); +} + +static int +do_sched_setscheduler(pid_t pid, int policy, struct sched_param __user *param) +{ + struct sched_param lparam; + struct task_struct *p; + int retval; + + if (!param || pid < 0) + return -EINVAL; + if (copy_from_user(&lparam, param, sizeof(struct sched_param))) + return -EFAULT; + + rcu_read_lock(); + retval = -ESRCH; + p = find_process_by_pid(pid); + if (p != NULL) + retval = sched_setscheduler(p, policy, &lparam); + rcu_read_unlock(); + + return retval; +} + +/** + * sys_sched_setscheduler - set/change the scheduler policy and RT priority + * @pid: the pid in question. + * @policy: new policy. + * @param: structure containing the new RT priority. + */ +asmlinkage long sys_sched_setscheduler(pid_t pid, int policy, + struct sched_param __user *param) +{ + /* negative values for policy are not valid */ + if (policy < 0) + return -EINVAL; + + return do_sched_setscheduler(pid, policy, param); +} + +/** + * sys_sched_setparam - set/change the RT priority of a thread + * @pid: the pid in question. + * @param: structure containing the new RT priority. + */ +SYSCALL_DEFINE2(sched_setparam, pid_t, pid, struct sched_param __user *, param) +{ + return do_sched_setscheduler(pid, -1, param); +} + +/** + * sys_sched_getscheduler - get the policy (scheduling class) of a thread + * @pid: the pid in question. + */ +SYSCALL_DEFINE1(sched_getscheduler, pid_t, pid) +{ + struct task_struct *p; + int retval = -EINVAL; + + if (pid < 0) + goto out_nounlock; + + retval = -ESRCH; + read_lock(&tasklist_lock); + p = find_process_by_pid(pid); + if (p) { + retval = security_task_getscheduler(p); + if (!retval) + retval = p->policy; + } + read_unlock(&tasklist_lock); + +out_nounlock: + return retval; +} + +/** + * sys_sched_getscheduler - get the RT priority of a thread + * @pid: the pid in question. + * @param: structure containing the RT priority. + */ +SYSCALL_DEFINE2(sched_getparam, pid_t, pid, struct sched_param __user *, param) +{ + struct sched_param lp; + struct task_struct *p; + int retval = -EINVAL; + + if (!param || pid < 0) + goto out_nounlock; + + read_lock(&tasklist_lock); + p = find_process_by_pid(pid); + retval = -ESRCH; + if (!p) + goto out_unlock; + + retval = security_task_getscheduler(p); + if (retval) + goto out_unlock; + + lp.sched_priority = p->rt_priority; + read_unlock(&tasklist_lock); + + /* + * This one might sleep, we cannot do it with a spinlock held ... + */ + retval = copy_to_user(param, &lp, sizeof(*param)) ? -EFAULT : 0; + +out_nounlock: + return retval; + +out_unlock: + read_unlock(&tasklist_lock); + return retval; +} + +long sched_setaffinity(pid_t pid, const struct cpumask *in_mask) +{ + cpumask_var_t cpus_allowed, new_mask; + struct task_struct *p; + int retval; + + get_online_cpus(); + read_lock(&tasklist_lock); + + p = find_process_by_pid(pid); + if (!p) { + read_unlock(&tasklist_lock); + put_online_cpus(); + return -ESRCH; + } + + /* + * It is not safe to call set_cpus_allowed with the + * tasklist_lock held. We will bump the task_struct's + * usage count and then drop tasklist_lock. + */ + get_task_struct(p); + read_unlock(&tasklist_lock); + + if (!alloc_cpumask_var(&cpus_allowed, GFP_KERNEL)) { + retval = -ENOMEM; + goto out_put_task; + } + if (!alloc_cpumask_var(&new_mask, GFP_KERNEL)) { + retval = -ENOMEM; + goto out_free_cpus_allowed; + } + retval = -EPERM; + if (!check_same_owner(p) && !capable(CAP_SYS_NICE)) + goto out_unlock; + + retval = security_task_setscheduler(p, 0, NULL); + if (retval) + goto out_unlock; + + cpuset_cpus_allowed(p, cpus_allowed); + cpumask_and(new_mask, in_mask, cpus_allowed); +again: + retval = set_cpus_allowed_ptr(p, new_mask); + + if (!retval) { + cpuset_cpus_allowed(p, cpus_allowed); + if (!cpumask_subset(new_mask, cpus_allowed)) { + /* + * We must have raced with a concurrent cpuset + * update. Just reset the cpus_allowed to the + * cpuset's cpus_allowed + */ + cpumask_copy(new_mask, cpus_allowed); + goto again; + } + } +out_unlock: + free_cpumask_var(new_mask); +out_free_cpus_allowed: + free_cpumask_var(cpus_allowed); +out_put_task: + put_task_struct(p); + put_online_cpus(); + return retval; +} + +static int get_user_cpu_mask(unsigned long __user *user_mask_ptr, unsigned len, + cpumask_t *new_mask) +{ + if (len < sizeof(cpumask_t)) { + memset(new_mask, 0, sizeof(cpumask_t)); + } else if (len > sizeof(cpumask_t)) { + len = sizeof(cpumask_t); + } + return copy_from_user(new_mask, user_mask_ptr, len) ? -EFAULT : 0; +} + + +/** + * sys_sched_setaffinity - set the cpu affinity of a process + * @pid: pid of the process + * @len: length in bytes of the bitmask pointed to by user_mask_ptr + * @user_mask_ptr: user-space pointer to the new cpu mask + */ +SYSCALL_DEFINE3(sched_setaffinity, pid_t, pid, unsigned int, len, + unsigned long __user *, user_mask_ptr) +{ + cpumask_var_t new_mask; + int retval; + + if (!alloc_cpumask_var(&new_mask, GFP_KERNEL)) + return -ENOMEM; + + retval = get_user_cpu_mask(user_mask_ptr, len, new_mask); + if (retval == 0) + retval = sched_setaffinity(pid, new_mask); + free_cpumask_var(new_mask); + return retval; +} + +long sched_getaffinity(pid_t pid, cpumask_t *mask) +{ + struct task_struct *p; + int retval; + + mutex_lock(&sched_hotcpu_mutex); + read_lock(&tasklist_lock); + + retval = -ESRCH; + p = find_process_by_pid(pid); + if (!p) + goto out_unlock; + + retval = security_task_getscheduler(p); + if (retval) + goto out_unlock; + + cpus_and(*mask, p->cpus_allowed, cpu_online_map); + +out_unlock: + read_unlock(&tasklist_lock); + mutex_unlock(&sched_hotcpu_mutex); + if (retval) + return retval; + + return 0; +} + +/** + * sys_sched_getaffinity - get the cpu affinity of a process + * @pid: pid of the process + * @len: length in bytes of the bitmask pointed to by user_mask_ptr + * @user_mask_ptr: user-space pointer to hold the current cpu mask + */ +SYSCALL_DEFINE3(sched_getaffinity, pid_t, pid, unsigned int, len, + unsigned long __user *, user_mask_ptr) +{ + int ret; + cpumask_var_t mask; + + if (len < cpumask_size()) + return -EINVAL; + + if (!alloc_cpumask_var(&mask, GFP_KERNEL)) + return -ENOMEM; + + ret = sched_getaffinity(pid, mask); + if (ret == 0) { + if (copy_to_user(user_mask_ptr, mask, cpumask_size())) + ret = -EFAULT; + else + ret = cpumask_size(); + } + free_cpumask_var(mask); + + return ret; +} + +/** + * sys_sched_yield - yield the current processor to other threads. + * + * This function yields the current CPU to other tasks. It does this by + * refilling the timeslice, resetting the deadline and scheduling away. + */ +SYSCALL_DEFINE0(sched_yield) +{ + struct task_struct *p; + + grq_lock_irq(); + p = current; + schedstat_inc(this_rq(), yld_count); + update_rq_clock(task_rq(p)); + time_slice_expired(p); + requeue_task(p); + + /* + * Since we are going to call schedule() anyway, there's + * no need to preempt or enable interrupts: + */ + __release(grq.lock); + spin_release(&grq.lock.dep_map, 1, _THIS_IP_); + _raw_spin_unlock(&grq.lock); + preempt_enable_no_resched(); + + schedule(); + + return 0; +} + +static void __cond_resched(void) +{ +#ifdef CONFIG_DEBUG_SPINLOCK_SLEEP + __might_sleep(__FILE__, __LINE__); +#endif + /* + * The BKS might be reacquired before we have dropped + * PREEMPT_ACTIVE, which could trigger a second + * cond_resched() call. + */ + do { + add_preempt_count(PREEMPT_ACTIVE); + schedule(); + sub_preempt_count(PREEMPT_ACTIVE); + } while (need_resched()); +} + +int __sched _cond_resched(void) +{ + if (need_resched() && !(preempt_count() & PREEMPT_ACTIVE) && + system_state == SYSTEM_RUNNING) { + __cond_resched(); + return 1; + } + return 0; +} +EXPORT_SYMBOL(_cond_resched); + +/* + * cond_resched_lock() - if a reschedule is pending, drop the given lock, + * call schedule, and on return reacquire the lock. + * + * This works OK both with and without CONFIG_PREEMPT. We do strange low-level + * operations here to prevent schedule() from being called twice (once via + * spin_unlock(), once by hand). + */ +int cond_resched_lock(spinlock_t *lock) +{ + int resched = need_resched() && system_state == SYSTEM_RUNNING; + int ret = 0; + + if (spin_needbreak(lock) || resched) { + spin_unlock(lock); + if (resched && need_resched()) + __cond_resched(); + else + cpu_relax(); + ret = 1; + spin_lock(lock); + } + return ret; +} +EXPORT_SYMBOL(cond_resched_lock); + +int __sched cond_resched_softirq(void) +{ + BUG_ON(!in_softirq()); + + if (need_resched() && system_state == SYSTEM_RUNNING) { + local_bh_enable(); + __cond_resched(); + local_bh_disable(); + return 1; + } + return 0; +} +EXPORT_SYMBOL(cond_resched_softirq); + +/** + * yield - yield the current processor to other threads. + * + * This is a shortcut for kernel-space yielding - it marks the + * thread runnable and calls sys_sched_yield(). + */ +void __sched yield(void) +{ + set_current_state(TASK_RUNNING); + sys_sched_yield(); +} +EXPORT_SYMBOL(yield); + +/* + * This task is about to go to sleep on IO. Increment rq->nr_iowait so + * that process accounting knows that this is a task in IO wait state. + * + * But don't do that if it is a deliberate, throttling IO wait (this task + * has set its backing_dev_info: the queue against which it should throttle) + */ +void __sched io_schedule(void) +{ + struct rq *rq = &__raw_get_cpu_var(runqueues); + + delayacct_blkio_start(); + atomic_inc(&rq->nr_iowait); + schedule(); + atomic_dec(&rq->nr_iowait); + delayacct_blkio_end(); +} +EXPORT_SYMBOL(io_schedule); + +long __sched io_schedule_timeout(long timeout) +{ + struct rq *rq = &__raw_get_cpu_var(runqueues); + long ret; + + delayacct_blkio_start(); + atomic_inc(&rq->nr_iowait); + ret = schedule_timeout(timeout); + atomic_dec(&rq->nr_iowait); + delayacct_blkio_end(); + return ret; +} + +/** + * sys_sched_get_priority_max - return maximum RT priority. + * @policy: scheduling class. + * + * this syscall returns the maximum rt_priority that can be used + * by a given scheduling class. + */ +SYSCALL_DEFINE1(sched_get_priority_max, int, policy) +{ + int ret = -EINVAL; + + switch (policy) { + case SCHED_FIFO: + case SCHED_RR: + ret = MAX_USER_RT_PRIO-1; + break; + case SCHED_NORMAL: + case SCHED_BATCH: + case SCHED_ISO: + case SCHED_IDLEPRIO: + ret = 0; + break; + } + return ret; +} + +/** + * sys_sched_get_priority_min - return minimum RT priority. + * @policy: scheduling class. + * + * this syscall returns the minimum rt_priority that can be used + * by a given scheduling class. + */ +SYSCALL_DEFINE1(sched_get_priority_min, int, policy) +{ + int ret = -EINVAL; + + switch (policy) { + case SCHED_FIFO: + case SCHED_RR: + ret = 1; + break; + case SCHED_NORMAL: + case SCHED_BATCH: + case SCHED_ISO: + case SCHED_IDLEPRIO: + ret = 0; + } + return ret; +} + +/** + * sys_sched_rr_get_interval - return the default timeslice of a process. + * @pid: pid of the process. + * @interval: userspace pointer to the timeslice value. + * + * this syscall writes the default timeslice value of a given process + * into the user-space timespec buffer. A value of '0' means infinity. + */ +SYSCALL_DEFINE2(sched_rr_get_interval, pid_t, pid, + struct timespec __user *, interval) +{ + struct task_struct *p; + int retval = -EINVAL; + struct timespec t; + + if (pid < 0) + goto out_nounlock; + + retval = -ESRCH; + read_lock(&tasklist_lock); + p = find_process_by_pid(pid); + if (!p) + goto out_unlock; + + retval = security_task_getscheduler(p); + if (retval) + goto out_unlock; + + t = ns_to_timespec(p->policy == SCHED_FIFO ? 0 : + MS_TO_NS(task_timeslice(p))); + read_unlock(&tasklist_lock); + retval = copy_to_user(interval, &t, sizeof(t)) ? -EFAULT : 0; +out_nounlock: + return retval; +out_unlock: + read_unlock(&tasklist_lock); + return retval; +} + +static const char stat_nam[] = TASK_STATE_TO_CHAR_STR; + +void sched_show_task(struct task_struct *p) +{ + unsigned long free = 0; + unsigned state; + + state = p->state ? __ffs(p->state) + 1 : 0; + printk(KERN_INFO "%-13.13s %c", p->comm, + state < sizeof(stat_nam) - 1 ? stat_nam[state] : '?'); +#if BITS_PER_LONG == 32 + if (state == TASK_RUNNING) + printk(KERN_CONT " running "); + else + printk(KERN_CONT " %08lx ", thread_saved_pc(p)); +#else + if (state == TASK_RUNNING) + printk(KERN_CONT " running task "); + else + printk(KERN_CONT " %016lx ", thread_saved_pc(p)); +#endif +#ifdef CONFIG_DEBUG_STACK_USAGE + free = stack_not_used(p); +#endif + printk(KERN_CONT "%5lu %5d %6d\n", free, + task_pid_nr(p), task_pid_nr(p->real_parent)); + + show_stack(p, NULL); +} + +void show_state_filter(unsigned long state_filter) +{ + struct task_struct *g, *p; + +#if BITS_PER_LONG == 32 + printk(KERN_INFO + " task PC stack pid father\n"); +#else + printk(KERN_INFO + " task PC stack pid father\n"); +#endif + read_lock(&tasklist_lock); + do_each_thread(g, p) { + /* + * reset the NMI-timeout, listing all files on a slow + * console might take alot of time: + */ + touch_nmi_watchdog(); + if (!state_filter || (p->state & state_filter)) + sched_show_task(p); + } while_each_thread(g, p); + + touch_all_softlockup_watchdogs(); + + read_unlock(&tasklist_lock); + /* + * Only show locks if all tasks are dumped: + */ + if (state_filter == -1) + debug_show_all_locks(); +} + +/** + * init_idle - set up an idle thread for a given CPU + * @idle: task in question + * @cpu: cpu the idle task belongs to + * + * NOTE: this function does not set the idle thread's NEED_RESCHED + * flag, to make booting more robust. + */ +void __cpuinit init_idle(struct task_struct *idle, int cpu) +{ + struct rq *rq = cpu_rq(cpu); + unsigned long flags; + + time_grq_lock(rq, &flags); + idle->timestamp = idle->last_ran = rq->clock; + idle->state = TASK_RUNNING; + /* Setting prio to illegal value shouldn't matter when never queued */ + idle->prio = PRIO_LIMIT; + idle->cpus_allowed = cpumask_of_cpu(cpu); + set_task_cpu(idle, cpu); + rq->curr = rq->idle = idle; + idle->oncpu = 1; + set_cpuidle_map(cpu); +#ifdef CONFIG_HOTPLUG_CPU + idle->unplugged_mask = CPU_MASK_NONE; +#endif + grq_unlock_irqrestore(&flags); + + /* Set the preempt count _outside_ the spinlocks! */ +#if defined(CONFIG_PREEMPT) && !defined(CONFIG_PREEMPT_BKL) + task_thread_info(idle)->preempt_count = (idle->lock_depth >= 0); +#else + task_thread_info(idle)->preempt_count = 0; +#endif + ftrace_graph_init_task(idle); +} + +/* + * In a system that switches off the HZ timer nohz_cpu_mask + * indicates which cpus entered this state. This is used + * in the rcu update to wait only for active cpus. For system + * which do not switch off the HZ timer nohz_cpu_mask should + * always be CPU_BITS_NONE. + */ +cpumask_var_t nohz_cpu_mask; + +#ifdef CONFIG_SMP +#ifdef CONFIG_NO_HZ +static struct { + atomic_t load_balancer; + cpumask_var_t cpu_mask; +} nohz ____cacheline_aligned = { + .load_balancer = ATOMIC_INIT(-1), +}; + +/* + * This routine will try to nominate the ilb (idle load balancing) + * owner among the cpus whose ticks are stopped. ilb owner will do the idle + * load balancing on behalf of all those cpus. If all the cpus in the system + * go into this tickless mode, then there will be no ilb owner (as there is + * no need for one) and all the cpus will sleep till the next wakeup event + * arrives... + * + * For the ilb owner, tick is not stopped. And this tick will be used + * for idle load balancing. ilb owner will still be part of + * nohz.cpu_mask.. + * + * While stopping the tick, this cpu will become the ilb owner if there + * is no other owner. And will be the owner till that cpu becomes busy + * or if all cpus in the system stop their ticks at which point + * there is no need for ilb owner. + * + * When the ilb owner becomes busy, it nominates another owner, during the + * next busy scheduler_tick() + */ +int select_nohz_load_balancer(int stop_tick) +{ + int cpu = smp_processor_id(); + + if (stop_tick) { + cpu_rq(cpu)->in_nohz_recently = 1; + + if (!cpu_active(cpu)) { + if (atomic_read(&nohz.load_balancer) != cpu) + return 0; + + /* + * If we are going offline and still the leader, + * give up! + */ + if (atomic_cmpxchg(&nohz.load_balancer, cpu, -1) != cpu) + BUG(); + + return 0; + } + + cpumask_set_cpu(cpu, nohz.cpu_mask); + + /* time for ilb owner also to sleep */ + if (cpumask_weight(nohz.cpu_mask) == num_online_cpus()) { + if (atomic_read(&nohz.load_balancer) == cpu) + atomic_set(&nohz.load_balancer, -1); + return 0; + } + + if (atomic_read(&nohz.load_balancer) == -1) { + /* make me the ilb owner */ + if (atomic_cmpxchg(&nohz.load_balancer, -1, cpu) == -1) + return 1; + } else if (atomic_read(&nohz.load_balancer) == cpu) + return 1; + } else { + if (!cpumask_test_cpu(cpu, nohz.cpu_mask)) + return 0; + + cpumask_clear_cpu(cpu, nohz.cpu_mask); + + if (atomic_read(&nohz.load_balancer) == cpu) + if (atomic_cmpxchg(&nohz.load_balancer, cpu, -1) != cpu) + BUG(); + } + return 0; +} + +/* + * When add_timer_on() enqueues a timer into the timer wheel of an + * idle CPU then this timer might expire before the next timer event + * which is scheduled to wake up that CPU. In case of a completely + * idle system the next event might even be infinite time into the + * future. wake_up_idle_cpu() ensures that the CPU is woken up and + * leaves the inner idle loop so the newly added timer is taken into + * account when the CPU goes back to idle and evaluates the timer + * wheel for the next timer event. + */ +void wake_up_idle_cpu(int cpu) +{ + struct task_struct *idle; + struct rq *rq; + + if (cpu == smp_processor_id()) + return; + + rq = cpu_rq(cpu); + idle = rq->idle; + + /* + * This is safe, as this function is called with the timer + * wheel base lock of (cpu) held. When the CPU is on the way + * to idle and has not yet set rq->curr to idle then it will + * be serialized on the timer wheel base lock and take the new + * timer into account automatically. + */ + if (unlikely(rq->curr != idle)) + return; + + /* + * We can set TIF_RESCHED on the idle task of the other CPU + * lockless. The worst case is that the other CPU runs the + * idle task through an additional NOOP schedule() + */ + set_tsk_need_resched(idle); + + /* NEED_RESCHED must be visible before we test polling */ + smp_mb(); + if (!tsk_is_polling(idle)) + smp_send_reschedule(cpu); +} + +#endif /* CONFIG_NO_HZ */ + +/* + * Change a given task's CPU affinity. Migrate the thread to a + * proper CPU and schedule it away if the CPU it's executing on + * is removed from the allowed bitmask. + * + * NOTE: the caller must have a valid reference to the task, the + * task must not exit() & deallocate itself prematurely. The + * call is not atomic; no spinlocks may be held. + */ +int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask) +{ + unsigned long flags; + struct rq *rq; + int ret = 0; + int running = 0; + + rq = task_grq_lock(p, &flags); + if (!cpumask_intersects(new_mask, cpu_online_mask)) { + ret = -EINVAL; + goto out; + } + + if (unlikely((p->flags & PF_THREAD_BOUND) && p != current && + !cpumask_equal(&p->cpus_allowed, new_mask))) { + ret = -EINVAL; + goto out; + } + + cpumask_copy(&p->cpus_allowed, new_mask); + p->rt_nr_cpus_allowed = cpumask_weight(new_mask); + + /* Can the task run on the task's current CPU? If so, we're done */ + if (cpumask_test_cpu(task_cpu(p), new_mask)) + goto out; + + /* Reschedule the task, schedule() will know if it can keep running */ + if (task_running(p)) + running = 1; + else + set_task_cpu(p, cpumask_any_and(cpu_online_mask, new_mask)); + +out: + task_grq_unlock(&flags); + + if (running) + schedule(); + return ret; +} +EXPORT_SYMBOL_GPL(set_cpus_allowed_ptr); + +#ifdef CONFIG_HOTPLUG_CPU +/* Schedules idle task to be the next runnable task on current CPU. + * It does so by boosting its priority to highest possible. + * Used by CPU offline code. + */ +void sched_idle_next(void) +{ + int this_cpu = smp_processor_id(); + struct rq *rq = cpu_rq(this_cpu); + struct task_struct *idle = rq->idle; + unsigned long flags; + + /* cpu has to be offline */ + BUG_ON(cpu_online(this_cpu)); + + /* + * Strictly not necessary since rest of the CPUs are stopped by now + * and interrupts disabled on the current cpu. + */ + time_grq_lock(rq, &flags); + + __setscheduler(idle, SCHED_FIFO, MAX_RT_PRIO - 1); + + activate_idle_task(idle); + rq->preempt_next = idle; + resched_task(rq->curr); + + grq_unlock_irqrestore(&flags); +} + +/* + * Ensures that the idle task is using init_mm right before its cpu goes + * offline. + */ +void idle_task_exit(void) +{ + struct mm_struct *mm = current->active_mm; + + BUG_ON(cpu_online(smp_processor_id())); + + if (mm != &init_mm) + switch_mm(mm, &init_mm, current); + mmdrop(mm); +} + +#endif /* CONFIG_HOTPLUG_CPU */ + +#if defined(CONFIG_SCHED_DEBUG) && defined(CONFIG_SYSCTL) + +static struct ctl_table sd_ctl_dir[] = { + { + .procname = "sched_domain", + .mode = 0555, + }, + {0, }, +}; + +static struct ctl_table sd_ctl_root[] = { + { + .ctl_name = CTL_KERN, + .procname = "kernel", + .mode = 0555, + .child = sd_ctl_dir, + }, + {0, }, +}; + +static struct ctl_table *sd_alloc_ctl_entry(int n) +{ + struct ctl_table *entry = + kcalloc(n, sizeof(struct ctl_table), GFP_KERNEL); + + return entry; +} + +static void sd_free_ctl_entry(struct ctl_table **tablep) +{ + struct ctl_table *entry; + + /* + * In the intermediate directories, both the child directory and + * procname are dynamically allocated and could fail but the mode + * will always be set. In the lowest directory the names are + * static strings and all have proc handlers. + */ + for (entry = *tablep; entry->mode; entry++) { + if (entry->child) + sd_free_ctl_entry(&entry->child); + if (entry->proc_handler == NULL) + kfree(entry->procname); + } + + kfree(*tablep); + *tablep = NULL; +} + +static void +set_table_entry(struct ctl_table *entry, + const char *procname, void *data, int maxlen, + mode_t mode, proc_handler *proc_handler) +{ + entry->procname = procname; + entry->data = data; + entry->maxlen = maxlen; + entry->mode = mode; + entry->proc_handler = proc_handler; +} + +static struct ctl_table * +sd_alloc_ctl_domain_table(struct sched_domain *sd) +{ + struct ctl_table *table = sd_alloc_ctl_entry(13); + + if (table == NULL) + return NULL; + + set_table_entry(&table[0], "min_interval", &sd->min_interval, + sizeof(long), 0644, proc_doulongvec_minmax); + set_table_entry(&table[1], "max_interval", &sd->max_interval, + sizeof(long), 0644, proc_doulongvec_minmax); + set_table_entry(&table[2], "busy_idx", &sd->busy_idx, + sizeof(int), 0644, proc_dointvec_minmax); + set_table_entry(&table[3], "idle_idx", &sd->idle_idx, + sizeof(int), 0644, proc_dointvec_minmax); + set_table_entry(&table[4], "newidle_idx", &sd->newidle_idx, + sizeof(int), 0644, proc_dointvec_minmax); + set_table_entry(&table[5], "wake_idx", &sd->wake_idx, + sizeof(int), 0644, proc_dointvec_minmax); + set_table_entry(&table[6], "forkexec_idx", &sd->forkexec_idx, + sizeof(int), 0644, proc_dointvec_minmax); + set_table_entry(&table[7], "busy_factor", &sd->busy_factor, + sizeof(int), 0644, proc_dointvec_minmax); + set_table_entry(&table[8], "imbalance_pct", &sd->imbalance_pct, + sizeof(int), 0644, proc_dointvec_minmax); + set_table_entry(&table[9], "cache_nice_tries", + &sd->cache_nice_tries, + sizeof(int), 0644, proc_dointvec_minmax); + set_table_entry(&table[10], "flags", &sd->flags, + sizeof(int), 0644, proc_dointvec_minmax); + set_table_entry(&table[11], "name", sd->name, + CORENAME_MAX_SIZE, 0444, proc_dostring); + /* &table[12] is terminator */ + + return table; +} + +static ctl_table *sd_alloc_ctl_cpu_table(int cpu) +{ + struct ctl_table *entry, *table; + struct sched_domain *sd; + int domain_num = 0, i; + char buf[32]; + + for_each_domain(cpu, sd) + domain_num++; + entry = table = sd_alloc_ctl_entry(domain_num + 1); + if (table == NULL) + return NULL; + + i = 0; + for_each_domain(cpu, sd) { + snprintf(buf, 32, "domain%d", i); + entry->procname = kstrdup(buf, GFP_KERNEL); + entry->mode = 0555; + entry->child = sd_alloc_ctl_domain_table(sd); + entry++; + i++; + } + return table; +} + +static struct ctl_table_header *sd_sysctl_header; +static void register_sched_domain_sysctl(void) +{ + int i, cpu_num = num_online_cpus(); + struct ctl_table *entry = sd_alloc_ctl_entry(cpu_num + 1); + char buf[32]; + + WARN_ON(sd_ctl_dir[0].child); + sd_ctl_dir[0].child = entry; + + if (entry == NULL) + return; + + for_each_online_cpu(i) { + snprintf(buf, 32, "cpu%d", i); + entry->procname = kstrdup(buf, GFP_KERNEL); + entry->mode = 0555; + entry->child = sd_alloc_ctl_cpu_table(i); + entry++; + } + + WARN_ON(sd_sysctl_header); + sd_sysctl_header = register_sysctl_table(sd_ctl_root); +} + +/* may be called multiple times per register */ +static void unregister_sched_domain_sysctl(void) +{ + if (sd_sysctl_header) + unregister_sysctl_table(sd_sysctl_header); + sd_sysctl_header = NULL; + if (sd_ctl_dir[0].child) + sd_free_ctl_entry(&sd_ctl_dir[0].child); +} +#else +static void register_sched_domain_sysctl(void) +{ +} +static void unregister_sched_domain_sysctl(void) +{ +} +#endif + +static void set_rq_online(struct rq *rq) +{ + if (!rq->online) { + cpumask_set_cpu(rq->cpu, rq->rd->online); + rq->online = 1; + } +} + +static void set_rq_offline(struct rq *rq) +{ + if (rq->online) { + cpumask_clear_cpu(rq->cpu, rq->rd->online); + rq->online = 0; + } +} + +#ifdef CONFIG_HOTPLUG_CPU +/* + * This cpu is going down, so walk over the tasklist and find tasks that can + * only run on this cpu and remove their affinity. Store their value in + * unplugged_mask so it can be restored once their correct cpu is online. No + * need to do anything special since they'll just move on next reschedule if + * they're running. + */ +static void remove_cpu(unsigned long cpu) +{ + struct task_struct *p, *t; + + read_lock(&tasklist_lock); + + do_each_thread(t, p) { + cpumask_t cpus_remaining; + + cpus_and(cpus_remaining, p->cpus_allowed, cpu_online_map); + cpu_clear(cpu, cpus_remaining); + if (cpus_empty(cpus_remaining)) { + p->unplugged_mask = p->cpus_allowed; + p->cpus_allowed = cpu_possible_map; + } + } while_each_thread(t, p); + + read_unlock(&tasklist_lock); +} + +/* + * This cpu is coming up so add it to the cpus_allowed. + */ +static void add_cpu(unsigned long cpu) +{ + struct task_struct *p, *t; + + read_lock(&tasklist_lock); + + do_each_thread(t, p) { + /* Have we taken all the cpus from the unplugged_mask back */ + if (cpus_empty(p->unplugged_mask)) + continue; + + /* Was this cpu in the unplugged_mask mask */ + if (cpu_isset(cpu, p->unplugged_mask)) { + cpu_set(cpu, p->cpus_allowed); + if (cpus_subset(p->unplugged_mask, p->cpus_allowed)) { + /* + * Have we set more than the unplugged_mask? + * If so, that means we have remnants set from + * the unplug/plug cycle and need to remove + * them. Then clear the unplugged_mask as we've + * set all the cpus back. + */ + p->cpus_allowed = p->unplugged_mask; + cpus_clear(p->unplugged_mask); + } + } + } while_each_thread(t, p); + + read_unlock(&tasklist_lock); +} +#else +static void add_cpu(unsigned long cpu) +{ +} +#endif + +/* + * migration_call - callback that gets triggered when a CPU is added. + */ +static int __cpuinit +migration_call(struct notifier_block *nfb, unsigned long action, void *hcpu) +{ + int cpu = (long)hcpu; + unsigned long flags; + struct rq *rq; + + switch (action) { + + case CPU_UP_PREPARE: + case CPU_UP_PREPARE_FROZEN: + break; + + case CPU_ONLINE: + case CPU_ONLINE_FROZEN: + /* Update our root-domain */ + rq = cpu_rq(cpu); + grq_lock_irqsave(&flags); + if (rq->rd) { + BUG_ON(!cpumask_test_cpu(cpu, rq->rd->span)); + + set_rq_online(rq); + } + add_cpu(cpu); + grq_unlock_irqrestore(&flags); + break; + +#ifdef CONFIG_HOTPLUG_CPU + case CPU_UP_CANCELED: + case CPU_UP_CANCELED_FROZEN: + break; + + case CPU_DEAD: + case CPU_DEAD_FROZEN: + cpuset_lock(); /* around calls to cpuset_cpus_allowed_lock() */ + rq = cpu_rq(cpu); + /* Idle task back to normal (off runqueue, low prio) */ + grq_lock_irq(); + remove_cpu(cpu); + deactivate_task(rq->idle); + rq->idle->static_prio = MAX_PRIO; + __setscheduler(rq->idle, SCHED_NORMAL, 0); + rq->idle->prio = PRIO_LIMIT; + update_rq_clock(rq); + grq_unlock_irq(); + cpuset_unlock(); + break; + + case CPU_DYING: + case CPU_DYING_FROZEN: + rq = cpu_rq(cpu); + grq_lock_irqsave(&flags); + if (rq->rd) { + BUG_ON(!cpumask_test_cpu(cpu, rq->rd->span)); + set_rq_offline(rq); + } + grq_unlock_irqrestore(&flags); + break; +#endif + } + return NOTIFY_OK; +} + +/* Register at highest priority so that task migration (migrate_all_tasks) + * happens before everything else. + */ +static struct notifier_block __cpuinitdata migration_notifier = { + .notifier_call = migration_call, + .priority = 10 +}; + +int __init migration_init(void) +{ + void *cpu = (void *)(long)smp_processor_id(); + int err; + + /* Start one for the boot CPU: */ + err = migration_call(&migration_notifier, CPU_UP_PREPARE, cpu); + BUG_ON(err == NOTIFY_BAD); + migration_call(&migration_notifier, CPU_ONLINE, cpu); + register_cpu_notifier(&migration_notifier); + + return 0; +} +early_initcall(migration_init); +#endif + +/* + * sched_domains_mutex serializes calls to arch_init_sched_domains, + * detach_destroy_domains and partition_sched_domains. + */ +static DEFINE_MUTEX(sched_domains_mutex); + +#ifdef CONFIG_SMP + +#ifdef CONFIG_SCHED_DEBUG + +static int sched_domain_debug_one(struct sched_domain *sd, int cpu, int level, + struct cpumask *groupmask) +{ + struct sched_group *group = sd->groups; + char str[256]; + + cpulist_scnprintf(str, sizeof(str), sched_domain_span(sd)); + cpumask_clear(groupmask); + + printk(KERN_DEBUG "%*s domain %d: ", level, "", level); + + if (!(sd->flags & SD_LOAD_BALANCE)) { + printk("does not load-balance\n"); + if (sd->parent) + printk(KERN_ERR "ERROR: !SD_LOAD_BALANCE domain" + " has parent"); + return -1; + } + + printk(KERN_CONT "span %s level %s\n", str, sd->name); + + if (!cpumask_test_cpu(cpu, sched_domain_span(sd))) { + printk(KERN_ERR "ERROR: domain->span does not contain " + "CPU%d\n", cpu); + } + if (!cpumask_test_cpu(cpu, sched_group_cpus(group))) { + printk(KERN_ERR "ERROR: domain->groups does not contain" + " CPU%d\n", cpu); + } + + printk(KERN_DEBUG "%*s groups:", level + 1, ""); + do { + if (!group) { + printk("\n"); + printk(KERN_ERR "ERROR: group is NULL\n"); + break; + } + + if (!group->__cpu_power) { + printk(KERN_CONT "\n"); + printk(KERN_ERR "ERROR: domain->cpu_power not " + "set\n"); + break; + } + + if (!cpumask_weight(sched_group_cpus(group))) { + printk(KERN_CONT "\n"); + printk(KERN_ERR "ERROR: empty group\n"); + break; + } + + if (cpumask_intersects(groupmask, sched_group_cpus(group))) { + printk(KERN_CONT "\n"); + printk(KERN_ERR "ERROR: repeated CPUs\n"); + break; + } + + cpumask_or(groupmask, groupmask, sched_group_cpus(group)); + + cpulist_scnprintf(str, sizeof(str), sched_group_cpus(group)); + + printk(KERN_CONT " %s", str); + if (group->__cpu_power != SCHED_LOAD_SCALE) { + printk(KERN_CONT " (__cpu_power = %d)", + group->__cpu_power); + } + + group = group->next; + } while (group != sd->groups); + printk(KERN_CONT "\n"); + + if (!cpumask_equal(sched_domain_span(sd), groupmask)) + printk(KERN_ERR "ERROR: groups don't span domain->span\n"); + + if (sd->parent && + !cpumask_subset(groupmask, sched_domain_span(sd->parent))) + printk(KERN_ERR "ERROR: parent span is not a superset " + "of domain->span\n"); + return 0; +} + +static void sched_domain_debug(struct sched_domain *sd, int cpu) +{ + cpumask_var_t groupmask; + int level = 0; + + if (!sd) { + printk(KERN_DEBUG "CPU%d attaching NULL sched-domain.\n", cpu); + return; + } + + printk(KERN_DEBUG "CPU%d attaching sched-domain:\n", cpu); + + if (!alloc_cpumask_var(&groupmask, GFP_KERNEL)) { + printk(KERN_DEBUG "Cannot load-balance (out of memory)\n"); + return; + } + + for (;;) { + if (sched_domain_debug_one(sd, cpu, level, groupmask)) + break; + level++; + sd = sd->parent; + if (!sd) + break; + } + free_cpumask_var(groupmask); +} +#else /* !CONFIG_SCHED_DEBUG */ +# define sched_domain_debug(sd, cpu) do { } while (0) +#endif /* CONFIG_SCHED_DEBUG */ + +static int sd_degenerate(struct sched_domain *sd) +{ + if (cpumask_weight(sched_domain_span(sd)) == 1) + return 1; + + /* Following flags need at least 2 groups */ + if (sd->flags & (SD_LOAD_BALANCE | + SD_BALANCE_NEWIDLE | + SD_BALANCE_FORK | + SD_BALANCE_EXEC | + SD_SHARE_CPUPOWER | + SD_SHARE_PKG_RESOURCES)) { + if (sd->groups != sd->groups->next) + return 0; + } + + /* Following flags don't use groups */ + if (sd->flags & (SD_WAKE_IDLE | + SD_WAKE_AFFINE | + SD_WAKE_BALANCE)) + return 0; + + return 1; +} + +static int +sd_parent_degenerate(struct sched_domain *sd, struct sched_domain *parent) +{ + unsigned long cflags = sd->flags, pflags = parent->flags; + + if (sd_degenerate(parent)) + return 1; + + if (!cpumask_equal(sched_domain_span(sd), sched_domain_span(parent))) + return 0; + + /* Does parent contain flags not in child? */ + /* WAKE_BALANCE is a subset of WAKE_AFFINE */ + if (cflags & SD_WAKE_AFFINE) + pflags &= ~SD_WAKE_BALANCE; + /* Flags needing groups don't count if only 1 group in parent */ + if (parent->groups == parent->groups->next) { + pflags &= ~(SD_LOAD_BALANCE | + SD_BALANCE_NEWIDLE | + SD_BALANCE_FORK | + SD_BALANCE_EXEC | + SD_SHARE_CPUPOWER | + SD_SHARE_PKG_RESOURCES); + if (nr_node_ids == 1) + pflags &= ~SD_SERIALIZE; + } + if (~cflags & pflags) + return 0; + + return 1; +} + +static void free_rootdomain(struct root_domain *rd) +{ + free_cpumask_var(rd->rto_mask); + free_cpumask_var(rd->online); + free_cpumask_var(rd->span); + kfree(rd); +} + +static void rq_attach_root(struct rq *rq, struct root_domain *rd) +{ + struct root_domain *old_rd = NULL; + unsigned long flags; + + grq_lock_irqsave(&flags); + + if (rq->rd) { + old_rd = rq->rd; + + if (cpumask_test_cpu(rq->cpu, old_rd->online)) + set_rq_offline(rq); + + cpumask_clear_cpu(rq->cpu, old_rd->span); + + /* + * If we dont want to free the old_rt yet then + * set old_rd to NULL to skip the freeing later + * in this function: + */ + if (!atomic_dec_and_test(&old_rd->refcount)) + old_rd = NULL; + } + + atomic_inc(&rd->refcount); + rq->rd = rd; + + cpumask_set_cpu(rq->cpu, rd->span); + if (cpumask_test_cpu(rq->cpu, cpu_online_mask)) + set_rq_online(rq); + + grq_unlock_irqrestore(&flags); + + if (old_rd) + free_rootdomain(old_rd); +} + +static int __init_refok init_rootdomain(struct root_domain *rd, bool bootmem) +{ + memset(rd, 0, sizeof(*rd)); + + if (bootmem) { + alloc_bootmem_cpumask_var(&def_root_domain.span); + alloc_bootmem_cpumask_var(&def_root_domain.online); + alloc_bootmem_cpumask_var(&def_root_domain.rto_mask); + return 0; + } + + if (!alloc_cpumask_var(&rd->span, GFP_KERNEL)) + goto out; + if (!alloc_cpumask_var(&rd->online, GFP_KERNEL)) + goto free_span; + if (!alloc_cpumask_var(&rd->rto_mask, GFP_KERNEL)) + goto free_online; + + return 0; + +free_online: + free_cpumask_var(rd->online); +free_span: + free_cpumask_var(rd->span); +out: + return -ENOMEM; +} + +static void init_defrootdomain(void) +{ + init_rootdomain(&def_root_domain, true); + + atomic_set(&def_root_domain.refcount, 1); +} + +static struct root_domain *alloc_rootdomain(void) +{ + struct root_domain *rd; + + rd = kmalloc(sizeof(*rd), GFP_KERNEL); + if (!rd) + return NULL; + + if (init_rootdomain(rd, false) != 0) { + kfree(rd); + return NULL; + } + + return rd; +} + +/* + * Attach the domain 'sd' to 'cpu' as its base domain. Callers must + * hold the hotplug lock. + */ +static void +cpu_attach_domain(struct sched_domain *sd, struct root_domain *rd, int cpu) +{ + struct rq *rq = cpu_rq(cpu); + struct sched_domain *tmp; + + /* Remove the sched domains which do not contribute to scheduling. */ + for (tmp = sd; tmp; ) { + struct sched_domain *parent = tmp->parent; + if (!parent) + break; + + if (sd_parent_degenerate(tmp, parent)) { + tmp->parent = parent->parent; + if (parent->parent) + parent->parent->child = tmp; + } else + tmp = tmp->parent; + } + + if (sd && sd_degenerate(sd)) { + sd = sd->parent; + if (sd) + sd->child = NULL; + } + + sched_domain_debug(sd, cpu); + + rq_attach_root(rq, rd); + rcu_assign_pointer(rq->sd, sd); +} + +/* cpus with isolated domains */ +static cpumask_var_t cpu_isolated_map; + +/* Setup the mask of cpus configured for isolated domains */ +static int __init isolated_cpu_setup(char *str) +{ + cpulist_parse(str, cpu_isolated_map); + return 1; +} + +__setup("isolcpus=", isolated_cpu_setup); + +/* + * init_sched_build_groups takes the cpumask we wish to span, and a pointer + * to a function which identifies what group(along with sched group) a CPU + * belongs to. The return value of group_fn must be a >= 0 and < nr_cpu_ids + * (due to the fact that we keep track of groups covered with a struct cpumask). + * + * init_sched_build_groups will build a circular linked list of the groups + * covered by the given span, and will set each group's ->cpumask correctly, + * and ->cpu_power to 0. + */ +static void +init_sched_build_groups(const struct cpumask *span, + const struct cpumask *cpu_map, + int (*group_fn)(int cpu, const struct cpumask *cpu_map, + struct sched_group **sg, + struct cpumask *tmpmask), + struct cpumask *covered, struct cpumask *tmpmask) +{ + struct sched_group *first = NULL, *last = NULL; + int i; + + cpumask_clear(covered); + + for_each_cpu(i, span) { + struct sched_group *sg; + int group = group_fn(i, cpu_map, &sg, tmpmask); + int j; + + if (cpumask_test_cpu(i, covered)) + continue; + + cpumask_clear(sched_group_cpus(sg)); + sg->__cpu_power = 0; + + for_each_cpu(j, span) { + if (group_fn(j, cpu_map, NULL, tmpmask) != group) + continue; + + cpumask_set_cpu(j, covered); + cpumask_set_cpu(j, sched_group_cpus(sg)); + } + if (!first) + first = sg; + if (last) + last->next = sg; + last = sg; + } + last->next = first; +} + +#define SD_NODES_PER_DOMAIN 16 + +#ifdef CONFIG_NUMA + +/** + * find_next_best_node - find the next node to include in a sched_domain + * @node: node whose sched_domain we're building + * @used_nodes: nodes already in the sched_domain + * + * Find the next node to include in a given scheduling domain. Simply + * finds the closest node not already in the @used_nodes map. + * + * Should use nodemask_t. + */ +static int find_next_best_node(int node, nodemask_t *used_nodes) +{ + int i, n, val, min_val, best_node = 0; + + min_val = INT_MAX; + + for (i = 0; i < nr_node_ids; i++) { + /* Start at @node */ + n = (node + i) % nr_node_ids; + + if (!nr_cpus_node(n)) + continue; + + /* Skip already used nodes */ + if (node_isset(n, *used_nodes)) + continue; + + /* Simple min distance search */ + val = node_distance(node, n); + + if (val < min_val) { + min_val = val; + best_node = n; + } + } + + node_set(best_node, *used_nodes); + return best_node; +} + +/** + * sched_domain_node_span - get a cpumask for a node's sched_domain + * @node: node whose cpumask we're constructing + * @span: resulting cpumask + * + * Given a node, construct a good cpumask for its sched_domain to span. It + * should be one that prevents unnecessary balancing, but also spreads tasks + * out optimally. + */ +static void sched_domain_node_span(int node, struct cpumask *span) +{ + nodemask_t used_nodes; + int i; + + cpumask_clear(span); + nodes_clear(used_nodes); + + cpumask_or(span, span, cpumask_of_node(node)); + node_set(node, used_nodes); + + for (i = 1; i < SD_NODES_PER_DOMAIN; i++) { + int next_node = find_next_best_node(node, &used_nodes); + + cpumask_or(span, span, cpumask_of_node(next_node)); + } +} +#endif /* CONFIG_NUMA */ + +int sched_smt_power_savings = 0, sched_mc_power_savings = 0; + +/* + * The cpus mask in sched_group and sched_domain hangs off the end. + * FIXME: use cpumask_var_t or dynamic percpu alloc to avoid wasting space + * for nr_cpu_ids < CONFIG_NR_CPUS. + */ +struct static_sched_group { + struct sched_group sg; + DECLARE_BITMAP(cpus, CONFIG_NR_CPUS); +}; + +struct static_sched_domain { + struct sched_domain sd; + DECLARE_BITMAP(span, CONFIG_NR_CPUS); +}; + +/* + * SMT sched-domains: + */ +#ifdef CONFIG_SCHED_SMT +static DEFINE_PER_CPU(struct static_sched_domain, cpu_domains); +static DEFINE_PER_CPU(struct static_sched_group, sched_group_cpus); + +static int +cpu_to_cpu_group(int cpu, const struct cpumask *cpu_map, + struct sched_group **sg, struct cpumask *unused) +{ + if (sg) + *sg = &per_cpu(sched_group_cpus, cpu).sg; + return cpu; +} +#endif /* CONFIG_SCHED_SMT */ + +/* + * multi-core sched-domains: + */ +#ifdef CONFIG_SCHED_MC +static DEFINE_PER_CPU(struct static_sched_domain, core_domains); +static DEFINE_PER_CPU(struct static_sched_group, sched_group_core); +#endif /* CONFIG_SCHED_MC */ + +#if defined(CONFIG_SCHED_MC) && defined(CONFIG_SCHED_SMT) +static int +cpu_to_core_group(int cpu, const struct cpumask *cpu_map, + struct sched_group **sg, struct cpumask *mask) +{ + int group; + + cpumask_and(mask, topology_thread_cpumask(cpu), cpu_map); + group = cpumask_first(mask); + if (sg) + *sg = &per_cpu(sched_group_core, group).sg; + return group; +} +#elif defined(CONFIG_SCHED_MC) +static int +cpu_to_core_group(int cpu, const struct cpumask *cpu_map, + struct sched_group **sg, struct cpumask *unused) +{ + if (sg) + *sg = &per_cpu(sched_group_core, cpu).sg; + return cpu; +} +#endif + +static DEFINE_PER_CPU(struct static_sched_domain, phys_domains); +static DEFINE_PER_CPU(struct static_sched_group, sched_group_phys); + +static int +cpu_to_phys_group(int cpu, const struct cpumask *cpu_map, + struct sched_group **sg, struct cpumask *mask) +{ + int group; +#ifdef CONFIG_SCHED_MC + cpumask_and(mask, cpu_coregroup_mask(cpu), cpu_map); + group = cpumask_first(mask); +#elif defined(CONFIG_SCHED_SMT) + cpumask_and(mask, topology_thread_cpumask(cpu), cpu_map); + group = cpumask_first(mask); +#else + group = cpu; +#endif + if (sg) + *sg = &per_cpu(sched_group_phys, group).sg; + return group; +} + +#ifdef CONFIG_NUMA +/* + * The init_sched_build_groups can't handle what we want to do with node + * groups, so roll our own. Now each node has its own list of groups which + * gets dynamically allocated. + */ +static DEFINE_PER_CPU(struct static_sched_domain, node_domains); +static struct sched_group ***sched_group_nodes_bycpu; + +static DEFINE_PER_CPU(struct static_sched_domain, allnodes_domains); +static DEFINE_PER_CPU(struct static_sched_group, sched_group_allnodes); + +static int cpu_to_allnodes_group(int cpu, const struct cpumask *cpu_map, + struct sched_group **sg, + struct cpumask *nodemask) +{ + int group; + + cpumask_and(nodemask, cpumask_of_node(cpu_to_node(cpu)), cpu_map); + group = cpumask_first(nodemask); + + if (sg) + *sg = &per_cpu(sched_group_allnodes, group).sg; + return group; +} + +static void init_numa_sched_groups_power(struct sched_group *group_head) +{ + struct sched_group *sg = group_head; + int j; + + if (!sg) + return; + do { + for_each_cpu(j, sched_group_cpus(sg)) { + struct sched_domain *sd; + + sd = &per_cpu(phys_domains, j).sd; + if (j != cpumask_first(sched_group_cpus(sd->groups))) { + /* + * Only add "power" once for each + * physical package. + */ + continue; + } + + sg_inc_cpu_power(sg, sd->groups->__cpu_power); + } + sg = sg->next; + } while (sg != group_head); +} +#endif /* CONFIG_NUMA */ + +#ifdef CONFIG_NUMA +/* Free memory allocated for various sched_group structures */ +static void free_sched_groups(const struct cpumask *cpu_map, + struct cpumask *nodemask) +{ + int cpu, i; + + for_each_cpu(cpu, cpu_map) { + struct sched_group **sched_group_nodes + = sched_group_nodes_bycpu[cpu]; + + if (!sched_group_nodes) + continue; + + for (i = 0; i < nr_node_ids; i++) { + struct sched_group *oldsg, *sg = sched_group_nodes[i]; + + cpumask_and(nodemask, cpumask_of_node(i), cpu_map); + if (cpumask_empty(nodemask)) + continue; + + if (sg == NULL) + continue; + sg = sg->next; +next_sg: + oldsg = sg; + sg = sg->next; + kfree(oldsg); + if (oldsg != sched_group_nodes[i]) + goto next_sg; + } + kfree(sched_group_nodes); + sched_group_nodes_bycpu[cpu] = NULL; + } +} +#else /* !CONFIG_NUMA */ +static void free_sched_groups(const struct cpumask *cpu_map, + struct cpumask *nodemask) +{ +} +#endif /* CONFIG_NUMA */ + +/* + * Initialize sched groups cpu_power. + * + * cpu_power indicates the capacity of sched group, which is used while + * distributing the load between different sched groups in a sched domain. + * Typically cpu_power for all the groups in a sched domain will be same unless + * there are asymmetries in the topology. If there are asymmetries, group + * having more cpu_power will pickup more load compared to the group having + * less cpu_power. + * + * cpu_power will be a multiple of SCHED_LOAD_SCALE. This multiple represents + * the maximum number of tasks a group can handle in the presence of other idle + * or lightly loaded groups in the same sched domain. + */ +static void init_sched_groups_power(int cpu, struct sched_domain *sd) +{ + struct sched_domain *child; + struct sched_group *group; + + WARN_ON(!sd || !sd->groups); + + if (cpu != cpumask_first(sched_group_cpus(sd->groups))) + return; + + child = sd->child; + + sd->groups->__cpu_power = 0; + + /* + * For perf policy, if the groups in child domain share resources + * (for example cores sharing some portions of the cache hierarchy + * or SMT), then set this domain groups cpu_power such that each group + * can handle only one task, when there are other idle groups in the + * same sched domain. + */ + if (!child || (!(sd->flags & SD_POWERSAVINGS_BALANCE) && + (child->flags & + (SD_SHARE_CPUPOWER | SD_SHARE_PKG_RESOURCES)))) { + sg_inc_cpu_power(sd->groups, SCHED_LOAD_SCALE); + return; + } + + /* + * add cpu_power of each child group to this groups cpu_power + */ + group = child->groups; + do { + sg_inc_cpu_power(sd->groups, group->__cpu_power); + group = group->next; + } while (group != child->groups); +} + +/* + * Initializers for schedule domains + * Non-inlined to reduce accumulated stack pressure in build_sched_domains() + */ + +#ifdef CONFIG_SCHED_DEBUG +# define SD_INIT_NAME(sd, type) sd->name = #type +#else +# define SD_INIT_NAME(sd, type) do { } while (0) +#endif + +#define SD_INIT(sd, type) sd_init_##type(sd) + +#define SD_INIT_FUNC(type) \ +static noinline void sd_init_##type(struct sched_domain *sd) \ +{ \ + memset(sd, 0, sizeof(*sd)); \ + *sd = SD_##type##_INIT; \ + sd->level = SD_LV_##type; \ + SD_INIT_NAME(sd, type); \ +} + +SD_INIT_FUNC(CPU) +#ifdef CONFIG_NUMA + SD_INIT_FUNC(ALLNODES) + SD_INIT_FUNC(NODE) +#endif +#ifdef CONFIG_SCHED_SMT + SD_INIT_FUNC(SIBLING) +#endif +#ifdef CONFIG_SCHED_MC + SD_INIT_FUNC(MC) +#endif + +static int default_relax_domain_level = -1; + +static int __init setup_relax_domain_level(char *str) +{ + unsigned long val; + + val = simple_strtoul(str, NULL, 0); + if (val < SD_LV_MAX) + default_relax_domain_level = val; + + return 1; +} +__setup("relax_domain_level=", setup_relax_domain_level); + +static void set_domain_attribute(struct sched_domain *sd, + struct sched_domain_attr *attr) +{ + int request; + + if (!attr || attr->relax_domain_level < 0) { + if (default_relax_domain_level < 0) + return; + else + request = default_relax_domain_level; + } else + request = attr->relax_domain_level; + if (request < sd->level) { + /* turn off idle balance on this domain */ + sd->flags &= ~(SD_WAKE_IDLE|SD_BALANCE_NEWIDLE); + } else { + /* turn on idle balance on this domain */ + sd->flags |= (SD_WAKE_IDLE_FAR|SD_BALANCE_NEWIDLE); + } +} + +/* + * Build sched domains for a given set of cpus and attach the sched domains + * to the individual cpus + */ +static int __build_sched_domains(const struct cpumask *cpu_map, + struct sched_domain_attr *attr) +{ + int i, err = -ENOMEM; + struct root_domain *rd; + cpumask_var_t nodemask, this_sibling_map, this_core_map, send_covered, + tmpmask; +#ifdef CONFIG_NUMA + cpumask_var_t domainspan, covered, notcovered; + struct sched_group **sched_group_nodes = NULL; + int sd_allnodes = 0; + + if (!alloc_cpumask_var(&domainspan, GFP_KERNEL)) + goto out; + if (!alloc_cpumask_var(&covered, GFP_KERNEL)) + goto free_domainspan; + if (!alloc_cpumask_var(¬covered, GFP_KERNEL)) + goto free_covered; +#endif + + if (!alloc_cpumask_var(&nodemask, GFP_KERNEL)) + goto free_notcovered; + if (!alloc_cpumask_var(&this_sibling_map, GFP_KERNEL)) + goto free_nodemask; + if (!alloc_cpumask_var(&this_core_map, GFP_KERNEL)) + goto free_this_sibling_map; + if (!alloc_cpumask_var(&send_covered, GFP_KERNEL)) + goto free_this_core_map; + if (!alloc_cpumask_var(&tmpmask, GFP_KERNEL)) + goto free_send_covered; + +#ifdef CONFIG_NUMA + /* + * Allocate the per-node list of sched groups + */ + sched_group_nodes = kcalloc(nr_node_ids, sizeof(struct sched_group *), + GFP_KERNEL); + if (!sched_group_nodes) { + printk(KERN_WARNING "Can not alloc sched group node list\n"); + goto free_tmpmask; + } +#endif + + rd = alloc_rootdomain(); + if (!rd) { + printk(KERN_WARNING "Cannot alloc root domain\n"); + goto free_sched_groups; + } + +#ifdef CONFIG_NUMA + sched_group_nodes_bycpu[cpumask_first(cpu_map)] = sched_group_nodes; +#endif + + /* + * Set up domains for cpus specified by the cpu_map. + */ + for_each_cpu(i, cpu_map) { + struct sched_domain *sd = NULL, *p; + + cpumask_and(nodemask, cpumask_of_node(cpu_to_node(i)), cpu_map); + +#ifdef CONFIG_NUMA + if (cpumask_weight(cpu_map) > + SD_NODES_PER_DOMAIN*cpumask_weight(nodemask)) { + sd = &per_cpu(allnodes_domains, i).sd; + SD_INIT(sd, ALLNODES); + set_domain_attribute(sd, attr); + cpumask_copy(sched_domain_span(sd), cpu_map); + cpu_to_allnodes_group(i, cpu_map, &sd->groups, tmpmask); + p = sd; + sd_allnodes = 1; + } else + p = NULL; + + sd = &per_cpu(node_domains, i).sd; + SD_INIT(sd, NODE); + set_domain_attribute(sd, attr); + sched_domain_node_span(cpu_to_node(i), sched_domain_span(sd)); + sd->parent = p; + if (p) + p->child = sd; + cpumask_and(sched_domain_span(sd), + sched_domain_span(sd), cpu_map); +#endif + + p = sd; + sd = &per_cpu(phys_domains, i).sd; + SD_INIT(sd, CPU); + set_domain_attribute(sd, attr); + cpumask_copy(sched_domain_span(sd), nodemask); + sd->parent = p; + if (p) + p->child = sd; + cpu_to_phys_group(i, cpu_map, &sd->groups, tmpmask); + +#ifdef CONFIG_SCHED_MC + p = sd; + sd = &per_cpu(core_domains, i).sd; + SD_INIT(sd, MC); + set_domain_attribute(sd, attr); + cpumask_and(sched_domain_span(sd), cpu_map, + cpu_coregroup_mask(i)); + sd->parent = p; + p->child = sd; + cpu_to_core_group(i, cpu_map, &sd->groups, tmpmask); +#endif + +#ifdef CONFIG_SCHED_SMT + p = sd; + sd = &per_cpu(cpu_domains, i).sd; + SD_INIT(sd, SIBLING); + set_domain_attribute(sd, attr); + cpumask_and(sched_domain_span(sd), + topology_thread_cpumask(i), cpu_map); + sd->parent = p; + p->child = sd; + cpu_to_cpu_group(i, cpu_map, &sd->groups, tmpmask); +#endif + } + +#ifdef CONFIG_SCHED_SMT + /* Set up CPU (sibling) groups */ + for_each_cpu(i, cpu_map) { + cpumask_and(this_sibling_map, + topology_thread_cpumask(i), cpu_map); + if (i != cpumask_first(this_sibling_map)) + continue; + + init_sched_build_groups(this_sibling_map, cpu_map, + &cpu_to_cpu_group, + send_covered, tmpmask); + } +#endif + +#ifdef CONFIG_SCHED_MC + /* Set up multi-core groups */ + for_each_cpu(i, cpu_map) { + cpumask_and(this_core_map, cpu_coregroup_mask(i), cpu_map); + if (i != cpumask_first(this_core_map)) + continue; + + init_sched_build_groups(this_core_map, cpu_map, + &cpu_to_core_group, + send_covered, tmpmask); + } +#endif + + /* Set up physical groups */ + for (i = 0; i < nr_node_ids; i++) { + cpumask_and(nodemask, cpumask_of_node(i), cpu_map); + if (cpumask_empty(nodemask)) + continue; + + init_sched_build_groups(nodemask, cpu_map, + &cpu_to_phys_group, + send_covered, tmpmask); + } + +#ifdef CONFIG_NUMA + /* Set up node groups */ + if (sd_allnodes) { + init_sched_build_groups(cpu_map, cpu_map, + &cpu_to_allnodes_group, + send_covered, tmpmask); + } + + for (i = 0; i < nr_node_ids; i++) { + /* Set up node groups */ + struct sched_group *sg, *prev; + int j; + + cpumask_clear(covered); + cpumask_and(nodemask, cpumask_of_node(i), cpu_map); + if (cpumask_empty(nodemask)) { + sched_group_nodes[i] = NULL; + continue; + } + + sched_domain_node_span(i, domainspan); + cpumask_and(domainspan, domainspan, cpu_map); + + sg = kmalloc_node(sizeof(struct sched_group) + cpumask_size(), + GFP_KERNEL, i); + if (!sg) { + printk(KERN_WARNING "Can not alloc domain group for " + "node %d\n", i); + goto error; + } + sched_group_nodes[i] = sg; + for_each_cpu(j, nodemask) { + struct sched_domain *sd; + + sd = &per_cpu(node_domains, j).sd; + sd->groups = sg; + } + sg->__cpu_power = 0; + cpumask_copy(sched_group_cpus(sg), nodemask); + sg->next = sg; + cpumask_or(covered, covered, nodemask); + prev = sg; + + for (j = 0; j < nr_node_ids; j++) { + int n = (i + j) % nr_node_ids; + + cpumask_complement(notcovered, covered); + cpumask_and(tmpmask, notcovered, cpu_map); + cpumask_and(tmpmask, tmpmask, domainspan); + if (cpumask_empty(tmpmask)) + break; + + cpumask_and(tmpmask, tmpmask, cpumask_of_node(n)); + if (cpumask_empty(tmpmask)) + continue; + + sg = kmalloc_node(sizeof(struct sched_group) + + cpumask_size(), + GFP_KERNEL, i); + if (!sg) { + printk(KERN_WARNING + "Can not alloc domain group for node %d\n", j); + goto error; + } + sg->__cpu_power = 0; + cpumask_copy(sched_group_cpus(sg), tmpmask); + sg->next = prev->next; + cpumask_or(covered, covered, tmpmask); + prev->next = sg; + prev = sg; + } + } +#endif + + /* Calculate CPU power for physical packages and nodes */ +#ifdef CONFIG_SCHED_SMT + for_each_cpu(i, cpu_map) { + struct sched_domain *sd = &per_cpu(cpu_domains, i).sd; + + init_sched_groups_power(i, sd); + } +#endif +#ifdef CONFIG_SCHED_MC + for_each_cpu(i, cpu_map) { + struct sched_domain *sd = &per_cpu(core_domains, i).sd; + + init_sched_groups_power(i, sd); + } +#endif + + for_each_cpu(i, cpu_map) { + struct sched_domain *sd = &per_cpu(phys_domains, i).sd; + + init_sched_groups_power(i, sd); + } + +#ifdef CONFIG_NUMA + for (i = 0; i < nr_node_ids; i++) + init_numa_sched_groups_power(sched_group_nodes[i]); + + if (sd_allnodes) { + struct sched_group *sg; + + cpu_to_allnodes_group(cpumask_first(cpu_map), cpu_map, &sg, + tmpmask); + init_numa_sched_groups_power(sg); + } +#endif + + /* Attach the domains */ + for_each_cpu(i, cpu_map) { + struct sched_domain *sd; +#ifdef CONFIG_SCHED_SMT + sd = &per_cpu(cpu_domains, i).sd; +#elif defined(CONFIG_SCHED_MC) + sd = &per_cpu(core_domains, i).sd; +#else + sd = &per_cpu(phys_domains, i).sd; +#endif + cpu_attach_domain(sd, rd, i); + } + + err = 0; + +free_tmpmask: + free_cpumask_var(tmpmask); +free_send_covered: + free_cpumask_var(send_covered); +free_this_core_map: + free_cpumask_var(this_core_map); +free_this_sibling_map: + free_cpumask_var(this_sibling_map); +free_nodemask: + free_cpumask_var(nodemask); +free_notcovered: +#ifdef CONFIG_NUMA + free_cpumask_var(notcovered); +free_covered: + free_cpumask_var(covered); +free_domainspan: + free_cpumask_var(domainspan); +out: +#endif + return err; + +free_sched_groups: +#ifdef CONFIG_NUMA + kfree(sched_group_nodes); +#endif + goto free_tmpmask; + +#ifdef CONFIG_NUMA +error: + free_sched_groups(cpu_map, tmpmask); + free_rootdomain(rd); + goto free_tmpmask; +#endif +} + +static int build_sched_domains(const struct cpumask *cpu_map) +{ + return __build_sched_domains(cpu_map, NULL); +} + +static struct cpumask *doms_cur; /* current sched domains */ +static int ndoms_cur; /* number of sched domains in 'doms_cur' */ +static struct sched_domain_attr *dattr_cur; + /* attribues of custom domains in 'doms_cur' */ + +/* + * Special case: If a kmalloc of a doms_cur partition (array of + * cpumask) fails, then fallback to a single sched domain, + * as determined by the single cpumask fallback_doms. + */ +static cpumask_var_t fallback_doms; + +/* + * arch_update_cpu_topology lets virtualized architectures update the + * cpu core maps. It is supposed to return 1 if the topology changed + * or 0 if it stayed the same. + */ +int __attribute__((weak)) arch_update_cpu_topology(void) +{ + return 0; +} + +/* + * Set up scheduler domains and groups. Callers must hold the hotplug lock. + * For now this just excludes isolated cpus, but could be used to + * exclude other special cases in the future. + */ +static int arch_init_sched_domains(const struct cpumask *cpu_map) +{ + int err; + + arch_update_cpu_topology(); + ndoms_cur = 1; + doms_cur = kmalloc(cpumask_size(), GFP_KERNEL); + if (!doms_cur) + doms_cur = fallback_doms; + cpumask_andnot(doms_cur, cpu_map, cpu_isolated_map); + dattr_cur = NULL; + err = build_sched_domains(doms_cur); + register_sched_domain_sysctl(); + + return err; +} + +static void arch_destroy_sched_domains(const struct cpumask *cpu_map, + struct cpumask *tmpmask) +{ + free_sched_groups(cpu_map, tmpmask); +} + +/* + * Detach sched domains from a group of cpus specified in cpu_map + * These cpus will now be attached to the NULL domain + */ +static void detach_destroy_domains(const struct cpumask *cpu_map) +{ + /* Save because hotplug lock held. */ + static DECLARE_BITMAP(tmpmask, CONFIG_NR_CPUS); + int i; + + for_each_cpu(i, cpu_map) + cpu_attach_domain(NULL, &def_root_domain, i); + synchronize_sched(); + arch_destroy_sched_domains(cpu_map, to_cpumask(tmpmask)); +} + +/* handle null as "default" */ +static int dattrs_equal(struct sched_domain_attr *cur, int idx_cur, + struct sched_domain_attr *new, int idx_new) +{ + struct sched_domain_attr tmp; + + /* fast path */ + if (!new && !cur) + return 1; + + tmp = SD_ATTR_INIT; + return !memcmp(cur ? (cur + idx_cur) : &tmp, + new ? (new + idx_new) : &tmp, + sizeof(struct sched_domain_attr)); +} + +/* + * Partition sched domains as specified by the 'ndoms_new' + * cpumasks in the array doms_new[] of cpumasks. This compares + * doms_new[] to the current sched domain partitioning, doms_cur[]. + * It destroys each deleted domain and builds each new domain. + * + * 'doms_new' is an array of cpumask's of length 'ndoms_new'. + * The masks don't intersect (don't overlap.) We should setup one + * sched domain for each mask. CPUs not in any of the cpumasks will + * not be load balanced. If the same cpumask appears both in the + * current 'doms_cur' domains and in the new 'doms_new', we can leave + * it as it is. + * + * The passed in 'doms_new' should be kmalloc'd. This routine takes + * ownership of it and will kfree it when done with it. If the caller + * failed the kmalloc call, then it can pass in doms_new == NULL && + * ndoms_new == 1, and partition_sched_domains() will fallback to + * the single partition 'fallback_doms', it also forces the domains + * to be rebuilt. + * + * If doms_new == NULL it will be replaced with cpu_online_mask. + * ndoms_new == 0 is a special case for destroying existing domains, + * and it will not create the default domain. + * + * Call with hotplug lock held + */ +/* FIXME: Change to struct cpumask *doms_new[] */ +void partition_sched_domains(int ndoms_new, struct cpumask *doms_new, + struct sched_domain_attr *dattr_new) +{ + int i, j, n; + int new_topology; + + mutex_lock(&sched_domains_mutex); + + /* always unregister in case we don't destroy any domains */ + unregister_sched_domain_sysctl(); + + /* Let architecture update cpu core mappings. */ + new_topology = arch_update_cpu_topology(); + + n = doms_new ? ndoms_new : 0; + + /* Destroy deleted domains */ + for (i = 0; i < ndoms_cur; i++) { + for (j = 0; j < n && !new_topology; j++) { + if (cpumask_equal(&doms_cur[i], &doms_new[j]) + && dattrs_equal(dattr_cur, i, dattr_new, j)) + goto match1; + } + /* no match - a current sched domain not in new doms_new[] */ + detach_destroy_domains(doms_cur + i); +match1: + ; + } + + if (doms_new == NULL) { + ndoms_cur = 0; + doms_new = fallback_doms; + cpumask_andnot(&doms_new[0], cpu_online_mask, cpu_isolated_map); + WARN_ON_ONCE(dattr_new); + } + + /* Build new domains */ + for (i = 0; i < ndoms_new; i++) { + for (j = 0; j < ndoms_cur && !new_topology; j++) { + if (cpumask_equal(&doms_new[i], &doms_cur[j]) + && dattrs_equal(dattr_new, i, dattr_cur, j)) + goto match2; + } + /* no match - add a new doms_new */ + __build_sched_domains(doms_new + i, + dattr_new ? dattr_new + i : NULL); +match2: + ; + } + + /* Remember the new sched domains */ + if (doms_cur != fallback_doms) + kfree(doms_cur); + kfree(dattr_cur); /* kfree(NULL) is safe */ + doms_cur = doms_new; + dattr_cur = dattr_new; + ndoms_cur = ndoms_new; + + register_sched_domain_sysctl(); + + mutex_unlock(&sched_domains_mutex); +} + +#if defined(CONFIG_SCHED_MC) || defined(CONFIG_SCHED_SMT) +static void arch_reinit_sched_domains(void) +{ + get_online_cpus(); + + /* Destroy domains first to force the rebuild */ + partition_sched_domains(0, NULL, NULL); + + rebuild_sched_domains(); + put_online_cpus(); +} + +static ssize_t sched_power_savings_store(const char *buf, size_t count, int smt) +{ + unsigned int level = 0; + + if (sscanf(buf, "%u", &level) != 1) + return -EINVAL; + + /* + * level is always be positive so don't check for + * level < POWERSAVINGS_BALANCE_NONE which is 0 + * What happens on 0 or 1 byte write, + * need to check for count as well? + */ + + if (level >= MAX_POWERSAVINGS_BALANCE_LEVELS) + return -EINVAL; + + if (smt) + sched_smt_power_savings = level; + else + sched_mc_power_savings = level; + + arch_reinit_sched_domains(); + + return count; +} + +#ifdef CONFIG_SCHED_MC +static ssize_t sched_mc_power_savings_show(struct sysdev_class *class, + char *page) +{ + return sprintf(page, "%u\n", sched_mc_power_savings); +} +static ssize_t sched_mc_power_savings_store(struct sysdev_class *class, + const char *buf, size_t count) +{ + return sched_power_savings_store(buf, count, 0); +} +static SYSDEV_CLASS_ATTR(sched_mc_power_savings, 0644, + sched_mc_power_savings_show, + sched_mc_power_savings_store); +#endif + +#ifdef CONFIG_SCHED_SMT +static ssize_t sched_smt_power_savings_show(struct sysdev_class *dev, + char *page) +{ + return sprintf(page, "%u\n", sched_smt_power_savings); +} +static ssize_t sched_smt_power_savings_store(struct sysdev_class *dev, + const char *buf, size_t count) +{ + return sched_power_savings_store(buf, count, 1); +} +static SYSDEV_CLASS_ATTR(sched_smt_power_savings, 0644, + sched_smt_power_savings_show, + sched_smt_power_savings_store); +#endif + +int __init sched_create_sysfs_power_savings_entries(struct sysdev_class *cls) +{ + int err = 0; + +#ifdef CONFIG_SCHED_SMT + if (smt_capable()) + err = sysfs_create_file(&cls->kset.kobj, + &attr_sched_smt_power_savings.attr); +#endif +#ifdef CONFIG_SCHED_MC + if (!err && mc_capable()) + err = sysfs_create_file(&cls->kset.kobj, + &attr_sched_mc_power_savings.attr); +#endif + return err; +} +#endif /* CONFIG_SCHED_MC || CONFIG_SCHED_SMT */ + +#ifndef CONFIG_CPUSETS +/* + * Add online and remove offline CPUs from the scheduler domains. + * When cpusets are enabled they take over this function. + */ +static int update_sched_domains(struct notifier_block *nfb, + unsigned long action, void *hcpu) +{ + switch (action) { + case CPU_ONLINE: + case CPU_ONLINE_FROZEN: + case CPU_DEAD: + case CPU_DEAD_FROZEN: + partition_sched_domains(1, NULL, NULL); + return NOTIFY_OK; + + default: + return NOTIFY_DONE; + } +} +#endif + +static int update_runtime(struct notifier_block *nfb, + unsigned long action, void *hcpu) +{ + switch (action) { + case CPU_DOWN_PREPARE: + case CPU_DOWN_PREPARE_FROZEN: + return NOTIFY_OK; + + case CPU_DOWN_FAILED: + case CPU_DOWN_FAILED_FROZEN: + case CPU_ONLINE: + case CPU_ONLINE_FROZEN: + return NOTIFY_OK; + + default: + return NOTIFY_DONE; + } +} + +void __init sched_init_smp(void) +{ + cpumask_var_t non_isolated_cpus; + + alloc_cpumask_var(&non_isolated_cpus, GFP_KERNEL); + +#if defined(CONFIG_NUMA) + sched_group_nodes_bycpu = kzalloc(nr_cpu_ids * sizeof(void **), + GFP_KERNEL); + BUG_ON(sched_group_nodes_bycpu == NULL); +#endif + get_online_cpus(); + mutex_lock(&sched_domains_mutex); + arch_init_sched_domains(cpu_online_mask); + cpumask_andnot(non_isolated_cpus, cpu_possible_mask, cpu_isolated_map); + if (cpumask_empty(non_isolated_cpus)) + cpumask_set_cpu(smp_processor_id(), non_isolated_cpus); + mutex_unlock(&sched_domains_mutex); + put_online_cpus(); + +#ifndef CONFIG_CPUSETS + /* XXX: Theoretical race here - CPU may be hotplugged now */ + hotcpu_notifier(update_sched_domains, 0); +#endif + + /* RT runtime code needs to handle some hotplug events */ + hotcpu_notifier(update_runtime, 0); + + /* Move init over to a non-isolated CPU */ + if (set_cpus_allowed_ptr(current, non_isolated_cpus) < 0) + BUG(); + free_cpumask_var(non_isolated_cpus); + + alloc_cpumask_var(&fallback_doms, GFP_KERNEL); + + /* + * Assume that every added cpu gives us slightly less overall latency + * allowing us to increase the base rr_interval, but in a non linear + * fashion. + */ + rr_interval *= 1 + ilog2(num_online_cpus()); +} +#else +void __init sched_init_smp(void) +{ +} +#endif /* CONFIG_SMP */ + +int in_sched_functions(unsigned long addr) +{ + return in_lock_functions(addr) || + (addr >= (unsigned long)__sched_text_start + && addr < (unsigned long)__sched_text_end); +} + +void __init sched_init(void) +{ + int i; + int highest_cpu = 0; + + prio_ratios[0] = 100; + for (i = 1 ; i < PRIO_RANGE ; i++) + prio_ratios[i] = prio_ratios[i - 1] * 11 / 10; + +#ifdef CONFIG_SMP + init_defrootdomain(); + cpus_clear(grq.cpu_idle_map); +#endif + spin_lock_init(&grq.lock); + for_each_possible_cpu(i) { + struct rq *rq; + + rq = cpu_rq(i); + rq->queued_deadline = 0; + rq->queued_prio = 0; + rq->preempt_next = NULL; + rq->cpu = i; +#ifdef CONFIG_SMP + rq->sd = NULL; + rq->rd = NULL; + rq->online = 0; + INIT_LIST_HEAD(&rq->migration_queue); + rq_attach_root(rq, &def_root_domain); +#endif + atomic_set(&rq->nr_iowait, 0); + highest_cpu = i; + } + grq.iso_ticks = grq.nr_running = grq.nr_uninterruptible = 0; + for (i = 0; i < PRIO_LIMIT; i++) + INIT_LIST_HEAD(grq.queue + i); + bitmap_zero(grq.prio_bitmap, PRIO_LIMIT); + /* delimiter for bitsearch */ + __set_bit(PRIO_LIMIT, grq.prio_bitmap); + +#ifdef CONFIG_SMP + nr_cpu_ids = highest_cpu + 1; +#endif + +#ifdef CONFIG_PREEMPT_NOTIFIERS + INIT_HLIST_HEAD(&init_task.preempt_notifiers); +#endif + +#ifdef CONFIG_RT_MUTEXES + plist_head_init(&init_task.pi_waiters, &init_task.pi_lock); +#endif + + /* + * The boot idle thread does lazy MMU switching as well: + */ + atomic_inc(&init_mm.mm_count); + enter_lazy_tlb(&init_mm, current); + + /* + * Make us the idle thread. Technically, schedule() should not be + * called from this thread, however somewhere below it might be, + * but because we are the idle thread, we just pick up running again + * when this runqueue becomes "idle". + */ + init_idle(current, smp_processor_id()); + + /* Allocate the nohz_cpu_mask if CONFIG_CPUMASK_OFFSTACK */ + alloc_bootmem_cpumask_var(&nohz_cpu_mask); +#ifdef CONFIG_SMP +#ifdef CONFIG_NO_HZ + alloc_bootmem_cpumask_var(&nohz.cpu_mask); +#endif + alloc_bootmem_cpumask_var(&cpu_isolated_map); +#endif /* SMP */ +} + +#ifdef CONFIG_DEBUG_SPINLOCK_SLEEP +void __might_sleep(char *file, int line) +{ +#ifdef in_atomic + static unsigned long prev_jiffy; /* ratelimiting */ + + if ((in_atomic() || irqs_disabled()) && + system_state == SYSTEM_RUNNING && !oops_in_progress) { + if (time_before(jiffies, prev_jiffy + HZ) && prev_jiffy) + return; + prev_jiffy = jiffies; + printk(KERN_ERR "BUG: sleeping function called from invalid" + " context at %s:%d\n", file, line); + printk("in_atomic():%d, irqs_disabled():%d\n", + in_atomic(), irqs_disabled()); + debug_show_held_locks(current); + if (irqs_disabled()) + print_irqtrace_events(current); + dump_stack(); + } +#endif +} +EXPORT_SYMBOL(__might_sleep); +#endif + +#ifdef CONFIG_MAGIC_SYSRQ +void normalize_rt_tasks(void) +{ + struct task_struct *g, *p; + unsigned long flags; + struct rq *rq; + int queued; + + read_lock_irq(&tasklist_lock); + + do_each_thread(g, p) { + if (!rt_task(p) && !iso_task(p)) + continue; + + spin_lock_irqsave(&p->pi_lock, flags); + rq = __task_grq_lock(p); + update_rq_clock(rq); + + queued = task_queued(p); + if (queued) + dequeue_task(p); + __setscheduler(p, SCHED_NORMAL, 0); + if (task_running(p)) + resched_task(p); + if (queued) { + enqueue_task(p); + try_preempt(p, rq); + } + + __task_grq_unlock(); + spin_unlock_irqrestore(&p->pi_lock, flags); + } while_each_thread(g, p); + + read_unlock_irq(&tasklist_lock); +} +#endif /* CONFIG_MAGIC_SYSRQ */ + +#ifdef CONFIG_IA64 +/* + * These functions are only useful for the IA64 MCA handling. + * + * They can only be called when the whole system has been + * stopped - every CPU needs to be quiescent, and no scheduling + * activity can take place. Using them for anything else would + * be a serious bug, and as a result, they aren't even visible + * under any other configuration. + */ + +/** + * curr_task - return the current task for a given cpu. + * @cpu: the processor in question. + * + * ONLY VALID WHEN THE WHOLE SYSTEM IS STOPPED! + */ +struct task_struct *curr_task(int cpu) +{ + return cpu_curr(cpu); +} + +/** + * set_curr_task - set the current task for a given cpu. + * @cpu: the processor in question. + * @p: the task pointer to set. + * + * Description: This function must only be used when non-maskable interrupts + * are serviced on a separate stack. It allows the architecture to switch the + * notion of the current task on a cpu in a non-blocking manner. This function + * must be called with all CPU's synchronized, and interrupts disabled, the + * and caller must save the original value of the current task (see + * curr_task() above) and restore that value before reenabling interrupts and + * re-starting the system. + * + * ONLY VALID WHEN THE WHOLE SYSTEM IS STOPPED! + */ +void set_curr_task(int cpu, struct task_struct *p) +{ + cpu_curr(cpu) = p; +} + +#endif + +/* + * Use precise platform statistics if available: + */ +#ifdef CONFIG_VIRT_CPU_ACCOUNTING +cputime_t task_utime(struct task_struct *p) +{ + return p->utime; +} + +cputime_t task_stime(struct task_struct *p) +{ + return p->stime; +} +#else +cputime_t task_utime(struct task_struct *p) +{ + clock_t utime = cputime_to_clock_t(p->utime), + total = utime + cputime_to_clock_t(p->stime); + u64 temp; + + temp = (u64)nsec_to_clock_t(p->sched_time); + + if (total) { + temp *= utime; + do_div(temp, total); + } + utime = (clock_t)temp; + + p->prev_utime = max(p->prev_utime, clock_t_to_cputime(utime)); + return p->prev_utime; +} + +cputime_t task_stime(struct task_struct *p) +{ + clock_t stime; + + stime = nsec_to_clock_t(p->sched_time) - + cputime_to_clock_t(task_utime(p)); + + if (stime >= 0) + p->prev_stime = max(p->prev_stime, clock_t_to_cputime(stime)); + + return p->prev_stime; +} +#endif + +inline cputime_t task_gtime(struct task_struct *p) +{ + return p->gtime; +} + +void __cpuinit init_idle_bootup_task(struct task_struct *idle) +{} + +#ifdef CONFIG_SCHED_DEBUG +void proc_sched_show_task(struct task_struct *p, struct seq_file *m) +{} + +void proc_sched_set_task(struct task_struct *p) +{} +#endif Index: linux-2.6.30-bfs/kernel/Makefile =================================================================== --- linux-2.6.30-bfs.orig/kernel/Makefile 2009-09-03 19:50:51.884053555 +1000 +++ linux-2.6.30-bfs/kernel/Makefile 2009-09-03 19:51:10.440054501 +1000 @@ -2,7 +2,7 @@ # Makefile for the linux kernel. # -obj-y = sched.o fork.o exec_domain.o panic.o printk.o \ +obj-y = sched_bfs.o fork.o exec_domain.o panic.o printk.o \ cpu.o exit.o itimer.o time.o softirq.o resource.o \ sysctl.o capability.o ptrace.o timer.o user.o \ signal.o sys.o kmod.o workqueue.o pid.o \ @@ -102,7 +102,7 @@ # me. I suspect most platforms don't need this, but until we know that for sure # I turn this off for IA-64 only. Andreas Schwab says it's also needed on m68k # to get a correct value for the wait-channel (WCHAN in ps). --davidm -CFLAGS_sched.o := $(PROFILING) -fno-omit-frame-pointer +CFLAGS_sched_bfs.o := $(PROFILING) -fno-omit-frame-pointer endif $(obj)/configs.o: $(obj)/config_data.h Index: linux-2.6.30-bfs/kernel/kthread.c =================================================================== --- linux-2.6.30-bfs.orig/kernel/kthread.c 2009-09-03 19:50:51.889054297 +1000 +++ linux-2.6.30-bfs/kernel/kthread.c 2009-09-03 19:51:10.490053542 +1000 @@ -15,7 +15,7 @@ #include <linux/mutex.h> #include <trace/sched.h> -#define KTHREAD_NICE_LEVEL (-5) +#define KTHREAD_NICE_LEVEL (0) static DEFINE_SPINLOCK(kthread_create_lock); static LIST_HEAD(kthread_create_list); @@ -180,7 +180,7 @@ } set_task_cpu(k, cpu); k->cpus_allowed = cpumask_of_cpu(cpu); - k->rt.nr_cpus_allowed = 1; + k->rt_nr_cpus_allowed = 1; k->flags |= PF_THREAD_BOUND; } EXPORT_SYMBOL(kthread_bind); Index: linux-2.6.30-bfs/kernel/posix-cpu-timers.c =================================================================== --- linux-2.6.30-bfs.orig/kernel/posix-cpu-timers.c 2009-09-03 19:50:51.857053341 +1000 +++ linux-2.6.30-bfs/kernel/posix-cpu-timers.c 2009-09-03 19:51:10.540060771 +1000 @@ -249,7 +249,7 @@ do { times->utime = cputime_add(times->utime, t->utime); times->stime = cputime_add(times->stime, t->stime); - times->sum_exec_runtime += t->se.sum_exec_runtime; + times->sum_exec_runtime += t->sched_time; t = next_thread(t); } while (t != tsk); @@ -516,7 +516,7 @@ void posix_cpu_timers_exit(struct task_struct *tsk) { cleanup_timers(tsk->cpu_timers, - tsk->utime, tsk->stime, tsk->se.sum_exec_runtime); + tsk->utime, tsk->stime, tsk->sched_time); } void posix_cpu_timers_exit_group(struct task_struct *tsk) @@ -1016,7 +1016,7 @@ struct cpu_timer_list *t = list_first_entry(timers, struct cpu_timer_list, entry); - if (!--maxfire || tsk->se.sum_exec_runtime < t->expires.sched) { + if (!--maxfire || tsk->sched_time < t->expires.sched) { tsk->cputime_expires.sched_exp = t->expires.sched; break; } @@ -1032,7 +1032,7 @@ unsigned long *soft = &sig->rlim[RLIMIT_RTTIME].rlim_cur; if (hard != RLIM_INFINITY && - tsk->rt.timeout > DIV_ROUND_UP(hard, USEC_PER_SEC/HZ)) { + tsk->rt_timeout > DIV_ROUND_UP(hard, USEC_PER_SEC/HZ)) { /* * At the hard limit, we just die. * No need to calculate anything else now. @@ -1040,7 +1040,7 @@ __group_send_sig_info(SIGKILL, SEND_SIG_PRIV, tsk); return; } - if (tsk->rt.timeout > DIV_ROUND_UP(*soft, USEC_PER_SEC/HZ)) { + if (tsk->rt_timeout > DIV_ROUND_UP(*soft, USEC_PER_SEC/HZ)) { /* * At the soft limit, send a SIGXCPU every second. */ @@ -1356,7 +1356,7 @@ struct task_cputime task_sample = { .utime = tsk->utime, .stime = tsk->stime, - .sum_exec_runtime = tsk->se.sum_exec_runtime + .sum_exec_runtime = tsk->sched_time }; if (task_cputime_expired(&task_sample, &tsk->cputime_expires)) Index: linux-2.6.30-bfs/kernel/exit.c =================================================================== --- linux-2.6.30-bfs.orig/kernel/exit.c 2009-09-03 19:50:51.872054089 +1000 +++ linux-2.6.30-bfs/kernel/exit.c 2009-09-03 19:51:10.607063074 +1000 @@ -124,7 +124,7 @@ sig->inblock += task_io_get_inblock(tsk); sig->oublock += task_io_get_oublock(tsk); task_io_accounting_add(&sig->ioac, &tsk->ioac); - sig->sum_sched_runtime += tsk->se.sum_exec_runtime; + sig->sum_sched_runtime += tsk->sched_time; sig = NULL; /* Marker for below. */ } @@ -146,10 +146,10 @@ flush_sigqueue(&sig->shared_pending); taskstats_tgid_free(sig); /* - * Make sure ->signal can't go away under rq->lock, + * Make sure ->signal can't go away under grq.lock, * see account_group_exec_runtime(). */ - task_rq_unlock_wait(tsk); + grq_unlock_wait(); __cleanup_signal(sig); } } Index: linux-2.6.30-bfs/kernel/fork.c =================================================================== --- linux-2.6.30-bfs.orig/kernel/fork.c 2009-09-03 19:50:51.862053392 +1000 +++ linux-2.6.30-bfs/kernel/fork.c 2009-09-03 19:51:10.665056329 +1000 @@ -1204,7 +1204,7 @@ * parent's CPU). This avoids alot of nasty races. */ p->cpus_allowed = current->cpus_allowed; - p->rt.nr_cpus_allowed = current->rt.nr_cpus_allowed; + p->rt_nr_cpus_allowed = current->rt_nr_cpus_allowed; if (unlikely(!cpu_isset(task_cpu(p), p->cpus_allowed) || !cpu_online(task_cpu(p)))) set_task_cpu(p, smp_processor_id()); Index: linux-2.6.30-bfs/mm/oom_kill.c =================================================================== --- linux-2.6.30-bfs.orig/mm/oom_kill.c 2009-09-03 19:50:51.901054980 +1000 +++ linux-2.6.30-bfs/mm/oom_kill.c 2009-09-03 19:51:10.731054188 +1000 @@ -338,7 +338,7 @@ * all the memory it needs. That way it should be able to * exit() and clear out its resources quickly... */ - p->rt.time_slice = HZ; + p->time_slice = HZ; set_tsk_thread_flag(p, TIF_MEMDIE); force_sig(SIGKILL, p); Index: linux-2.6.30-bfs/init/Kconfig =================================================================== --- linux-2.6.30-bfs.orig/init/Kconfig 2009-09-03 19:50:51.914054644 +1000 +++ linux-2.6.30-bfs/init/Kconfig 2009-09-03 23:38:22.334259229 +1000 @@ -435,65 +435,13 @@ config HAVE_UNSTABLE_SCHED_CLOCK bool -config GROUP_SCHED - bool "Group CPU scheduler" - depends on EXPERIMENTAL - default n - help - This feature lets CPU scheduler recognize task groups and control CPU - bandwidth allocation to such task groups. - In order to create a group from arbitrary set of processes, use - CONFIG_CGROUPS. (See Control Group support.) - -config FAIR_GROUP_SCHED - bool "Group scheduling for SCHED_OTHER" - depends on GROUP_SCHED - default GROUP_SCHED - -config RT_GROUP_SCHED - bool "Group scheduling for SCHED_RR/FIFO" - depends on EXPERIMENTAL - depends on GROUP_SCHED - default n - help - This feature lets you explicitly allocate real CPU bandwidth - to users or control groups (depending on the "Basis for grouping tasks" - setting below. If enabled, it will also make it impossible to - schedule realtime tasks for non-root users until you allocate - realtime bandwidth for them. - See Documentation/scheduler/sched-rt-group.txt for more information. - -choice - depends on GROUP_SCHED - prompt "Basis for grouping tasks" - default USER_SCHED - -config USER_SCHED - bool "user id" - help - This option will choose userid as the basis for grouping - tasks, thus providing equal CPU bandwidth to each user. - -config CGROUP_SCHED - bool "Control groups" - depends on CGROUPS - help - This option allows you to create arbitrary task groups - using the "cgroup" pseudo filesystem and control - the cpu bandwidth allocated to each such task group. - Refer to Documentation/cgroups/cgroups.txt for more - information on "cgroup" pseudo filesystem. - -endchoice - menuconfig CGROUPS boolean "Control Group support" help This option adds support for grouping sets of processes together, for - use with process control subsystems such as Cpusets, CFS, memory + use with process control subsystems such as Cpusets, memory controls or device isolation. See - - Documentation/scheduler/sched-design-CFS.txt (CFS) - Documentation/cgroups/ (features for grouping, isolation and resource control) @@ -551,13 +499,6 @@ depends on CPUSETS default y -config CGROUP_CPUACCT - bool "Simple CPU accounting cgroup subsystem" - depends on CGROUPS - help - Provides a simple Resource Controller for monitoring the - total CPU consumed by the tasks in a cgroup. - config RESOURCE_COUNTERS bool "Resource counters" help Index: linux-2.6.30-bfs/kernel/delayacct.c =================================================================== --- linux-2.6.30-bfs.orig/kernel/delayacct.c 2009-09-03 19:50:51.824054121 +1000 +++ linux-2.6.30-bfs/kernel/delayacct.c 2009-09-03 19:51:10.839054130 +1000 @@ -127,7 +127,7 @@ */ t1 = tsk->sched_info.pcount; t2 = tsk->sched_info.run_delay; - t3 = tsk->se.sum_exec_runtime; + t3 = tsk->sched_time; d->cpu_count += t1; Index: linux-2.6.30-bfs/kernel/trace/trace.c =================================================================== --- linux-2.6.30-bfs.orig/kernel/trace/trace.c 2009-09-03 19:50:51.830053561 +1000 +++ linux-2.6.30-bfs/kernel/trace/trace.c 2009-09-03 19:51:10.866055007 +1000 @@ -266,10 +266,10 @@ void trace_wake_up(void) { /* - * The runqueue_is_locked() can fail, but this is the best we + * The grunqueue_is_locked() can fail, but this is the best we * have for now: */ - if (!(trace_flags & TRACE_ITER_BLOCK) && !runqueue_is_locked()) + if (!(trace_flags & TRACE_ITER_BLOCK) && !grunqueue_is_locked()) wake_up(&trace_wait); } Index: linux-2.6.30-bfs/fs/proc/base.c =================================================================== --- linux-2.6.30-bfs.orig/fs/proc/base.c 2009-09-03 19:50:51.789053856 +1000 +++ linux-2.6.30-bfs/fs/proc/base.c 2009-09-03 19:51:10.922053915 +1000 @@ -369,7 +369,7 @@ static int proc_pid_schedstat(struct task_struct *task, char *buffer) { return sprintf(buffer, "%llu %llu %lu\n", - (unsigned long long)task->se.sum_exec_runtime, + (unsigned long long)task->sched_time, (unsigned long long)task->sched_info.run_delay, task->sched_info.pcount); } Index: linux-2.6.30-bfs/kernel/sched_debug.c =================================================================== --- linux-2.6.30-bfs.orig/kernel/sched_debug.c 2009-09-03 19:50:51.841053602 +1000 +++ /dev/null 1970-01-01 00:00:00.000000000 +0000 @@ -1,509 +0,0 @@ -/* - * kernel/time/sched_debug.c - * - * Print the CFS rbtree - * - * Copyright(C) 2007, Red Hat, Inc., Ingo Molnar - * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License version 2 as - * published by the Free Software Foundation. - */ - -#include <linux/proc_fs.h> -#include <linux/sched.h> -#include <linux/seq_file.h> -#include <linux/kallsyms.h> -#include <linux/utsname.h> - -/* - * This allows printing both to /proc/sched_debug and - * to the console - */ -#define SEQ_printf(m, x...) \ - do { \ - if (m) \ - seq_printf(m, x); \ - else \ - printk(x); \ - } while (0) - -/* - * Ease the printing of nsec fields: - */ -static long long nsec_high(unsigned long long nsec) -{ - if ((long long)nsec < 0) { - nsec = -nsec; - do_div(nsec, 1000000); - return -nsec; - } - do_div(nsec, 1000000); - - return nsec; -} - -static unsigned long nsec_low(unsigned long long nsec) -{ - if ((long long)nsec < 0) - nsec = -nsec; - - return do_div(nsec, 1000000); -} - -#define SPLIT_NS(x) nsec_high(x), nsec_low(x) - -#ifdef CONFIG_FAIR_GROUP_SCHED -static void print_cfs_group_stats(struct seq_file *m, int cpu, - struct task_group *tg) -{ - struct sched_entity *se = tg->se[cpu]; - if (!se) - return; - -#define P(F) \ - SEQ_printf(m, " .%-30s: %lld\n", #F, (long long)F) -#define PN(F) \ - SEQ_printf(m, " .%-30s: %lld.%06ld\n", #F, SPLIT_NS((long long)F)) - - PN(se->exec_start); - PN(se->vruntime); - PN(se->sum_exec_runtime); -#ifdef CONFIG_SCHEDSTATS - PN(se->wait_start); - PN(se->sleep_start); - PN(se->block_start); - PN(se->sleep_max); - PN(se->block_max); - PN(se->exec_max); - PN(se->slice_max); - PN(se->wait_max); - PN(se->wait_sum); - P(se->wait_count); -#endif - P(se->load.weight); -#undef PN -#undef P -} -#endif - -static void -print_task(struct seq_file *m, struct rq *rq, struct task_struct *p) -{ - if (rq->curr == p) - SEQ_printf(m, "R"); - else - SEQ_printf(m, " "); - - SEQ_printf(m, "%15s %5d %9Ld.%06ld %9Ld %5d ", - p->comm, p->pid, - SPLIT_NS(p->se.vruntime), - (long long)(p->nvcsw + p->nivcsw), - p->prio); -#ifdef CONFIG_SCHEDSTATS - SEQ_printf(m, "%9Ld.%06ld %9Ld.%06ld %9Ld.%06ld", - SPLIT_NS(p->se.vruntime), - SPLIT_NS(p->se.sum_exec_runtime), - SPLIT_NS(p->se.sum_sleep_runtime)); -#else - SEQ_printf(m, "%15Ld %15Ld %15Ld.%06ld %15Ld.%06ld %15Ld.%06ld", - 0LL, 0LL, 0LL, 0L, 0LL, 0L, 0LL, 0L); -#endif - -#ifdef CONFIG_CGROUP_SCHED - { - char path[64]; - - cgroup_path(task_group(p)->css.cgroup, path, sizeof(path)); - SEQ_printf(m, " %s", path); - } -#endif - SEQ_printf(m, "\n"); -} - -static void print_rq(struct seq_file *m, struct rq *rq, int rq_cpu) -{ - struct task_struct *g, *p; - unsigned long flags; - - SEQ_printf(m, - "\nrunnable tasks:\n" - " task PID tree-key switches prio" - " exec-runtime sum-exec sum-sleep\n" - "------------------------------------------------------" - "----------------------------------------------------\n"); - - read_lock_irqsave(&tasklist_lock, flags); - - do_each_thread(g, p) { - if (!p->se.on_rq || task_cpu(p) != rq_cpu) - continue; - - print_task(m, rq, p); - } while_each_thread(g, p); - - read_unlock_irqrestore(&tasklist_lock, flags); -} - -#if defined(CONFIG_CGROUP_SCHED) && \ - (defined(CONFIG_FAIR_GROUP_SCHED) || defined(CONFIG_RT_GROUP_SCHED)) -static void task_group_path(struct task_group *tg, char *buf, int buflen) -{ - /* may be NULL if the underlying cgroup isn't fully-created yet */ - if (!tg->css.cgroup) { - buf[0] = '\0'; - return; - } - cgroup_path(tg->css.cgroup, buf, buflen); -} -#endif - -void print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq) -{ - s64 MIN_vruntime = -1, min_vruntime, max_vruntime = -1, - spread, rq0_min_vruntime, spread0; - struct rq *rq = &per_cpu(runqueues, cpu); - struct sched_entity *last; - unsigned long flags; - -#if defined(CONFIG_CGROUP_SCHED) && defined(CONFIG_FAIR_GROUP_SCHED) - char path[128]; - struct task_group *tg = cfs_rq->tg; - - task_group_path(tg, path, sizeof(path)); - - SEQ_printf(m, "\ncfs_rq[%d]:%s\n", cpu, path); -#elif defined(CONFIG_USER_SCHED) && defined(CONFIG_FAIR_GROUP_SCHED) - { - uid_t uid = cfs_rq->tg->uid; - SEQ_printf(m, "\ncfs_rq[%d] for UID: %u\n", cpu, uid); - } -#else - SEQ_printf(m, "\ncfs_rq[%d]:\n", cpu); -#endif - SEQ_printf(m, " .%-30s: %Ld.%06ld\n", "exec_clock", - SPLIT_NS(cfs_rq->exec_clock)); - - spin_lock_irqsave(&rq->lock, flags); - if (cfs_rq->rb_leftmost) - MIN_vruntime = (__pick_next_entity(cfs_rq))->vruntime; - last = __pick_last_entity(cfs_rq); - if (last) - max_vruntime = last->vruntime; - min_vruntime = cfs_rq->min_vruntime; - rq0_min_vruntime = per_cpu(runqueues, 0).cfs.min_vruntime; - spin_unlock_irqrestore(&rq->lock, flags); - SEQ_printf(m, " .%-30s: %Ld.%06ld\n", "MIN_vruntime", - SPLIT_NS(MIN_vruntime)); - SEQ_printf(m, " .%-30s: %Ld.%06ld\n", "min_vruntime", - SPLIT_NS(min_vruntime)); - SEQ_printf(m, " .%-30s: %Ld.%06ld\n", "max_vruntime", - SPLIT_NS(max_vruntime)); - spread = max_vruntime - MIN_vruntime; - SEQ_printf(m, " .%-30s: %Ld.%06ld\n", "spread", - SPLIT_NS(spread)); - spread0 = min_vruntime - rq0_min_vruntime; - SEQ_printf(m, " .%-30s: %Ld.%06ld\n", "spread0", - SPLIT_NS(spread0)); - SEQ_printf(m, " .%-30s: %ld\n", "nr_running", cfs_rq->nr_running); - SEQ_printf(m, " .%-30s: %ld\n", "load", cfs_rq->load.weight); - - SEQ_printf(m, " .%-30s: %d\n", "nr_spread_over", - cfs_rq->nr_spread_over); -#ifdef CONFIG_FAIR_GROUP_SCHED -#ifdef CONFIG_SMP - SEQ_printf(m, " .%-30s: %lu\n", "shares", cfs_rq->shares); -#endif - print_cfs_group_stats(m, cpu, cfs_rq->tg); -#endif -} - -void print_rt_rq(struct seq_file *m, int cpu, struct rt_rq *rt_rq) -{ -#if defined(CONFIG_CGROUP_SCHED) && defined(CONFIG_RT_GROUP_SCHED) - char path[128]; - struct task_group *tg = rt_rq->tg; - - task_group_path(tg, path, sizeof(path)); - - SEQ_printf(m, "\nrt_rq[%d]:%s\n", cpu, path); -#else - SEQ_printf(m, "\nrt_rq[%d]:\n", cpu); -#endif - - -#define P(x) \ - SEQ_printf(m, " .%-30s: %Ld\n", #x, (long long)(rt_rq->x)) -#define PN(x) \ - SEQ_printf(m, " .%-30s: %Ld.%06ld\n", #x, SPLIT_NS(rt_rq->x)) - - P(rt_nr_running); - P(rt_throttled); - PN(rt_time); - PN(rt_runtime); - -#undef PN -#undef P -} - -static void print_cpu(struct seq_file *m, int cpu) -{ - struct rq *rq = &per_cpu(runqueues, cpu); - -#ifdef CONFIG_X86 - { - unsigned int freq = cpu_khz ? : 1; - - SEQ_printf(m, "\ncpu#%d, %u.%03u MHz\n", - cpu, freq / 1000, (freq % 1000)); - } -#else - SEQ_printf(m, "\ncpu#%d\n", cpu); -#endif - -#define P(x) \ - SEQ_printf(m, " .%-30s: %Ld\n", #x, (long long)(rq->x)) -#define PN(x) \ - SEQ_printf(m, " .%-30s: %Ld.%06ld\n", #x, SPLIT_NS(rq->x)) - - P(nr_running); - SEQ_printf(m, " .%-30s: %lu\n", "load", - rq->load.weight); - P(nr_switches); - P(nr_load_updates); - P(nr_uninterruptible); - PN(next_balance); - P(curr->pid); - PN(clock); - P(cpu_load[0]); - P(cpu_load[1]); - P(cpu_load[2]); - P(cpu_load[3]); - P(cpu_load[4]); -#undef P -#undef PN - -#ifdef CONFIG_SCHEDSTATS -#define P(n) SEQ_printf(m, " .%-30s: %d\n", #n, rq->n); - - P(yld_count); - - P(sched_switch); - P(sched_count); - P(sched_goidle); - - P(ttwu_count); - P(ttwu_local); - - P(bkl_count); - -#undef P -#endif - print_cfs_stats(m, cpu); - print_rt_stats(m, cpu); - - print_rq(m, rq, cpu); -} - -static int sched_debug_show(struct seq_file *m, void *v) -{ - u64 now = ktime_to_ns(ktime_get()); - int cpu; - - SEQ_printf(m, "Sched Debug Version: v0.09, %s %.*s\n", - init_utsname()->release, - (int)strcspn(init_utsname()->version, " "), - init_utsname()->version); - - SEQ_printf(m, "now at %Lu.%06ld msecs\n", SPLIT_NS(now)); - -#define P(x) \ - SEQ_printf(m, " .%-40s: %Ld\n", #x, (long long)(x)) -#define PN(x) \ - SEQ_printf(m, " .%-40s: %Ld.%06ld\n", #x, SPLIT_NS(x)) - P(jiffies); - PN(sysctl_sched_latency); - PN(sysctl_sched_min_granularity); - PN(sysctl_sched_wakeup_granularity); - PN(sysctl_sched_child_runs_first); - P(sysctl_sched_features); -#undef PN -#undef P - - for_each_online_cpu(cpu) - print_cpu(m, cpu); - - SEQ_printf(m, "\n"); - - return 0; -} - -static void sysrq_sched_debug_show(void) -{ - sched_debug_show(NULL, NULL); -} - -static int sched_debug_open(struct inode *inode, struct file *filp) -{ - return single_open(filp, sched_debug_show, NULL); -} - -static const struct file_operations sched_debug_fops = { - .open = sched_debug_open, - .read = seq_read, - .llseek = seq_lseek, - .release = single_release, -}; - -static int __init init_sched_debug_procfs(void) -{ - struct proc_dir_entry *pe; - - pe = proc_create("sched_debug", 0444, NULL, &sched_debug_fops); - if (!pe) - return -ENOMEM; - return 0; -} - -__initcall(init_sched_debug_procfs); - -void proc_sched_show_task(struct task_struct *p, struct seq_file *m) -{ - unsigned long nr_switches; - unsigned long flags; - int num_threads = 1; - - if (lock_task_sighand(p, &flags)) { - num_threads = atomic_read(&p->signal->count); - unlock_task_sighand(p, &flags); - } - - SEQ_printf(m, "%s (%d, #threads: %d)\n", p->comm, p->pid, num_threads); - SEQ_printf(m, - "---------------------------------------------------------\n"); -#define __P(F) \ - SEQ_printf(m, "%-35s:%21Ld\n", #F, (long long)F) -#define P(F) \ - SEQ_printf(m, "%-35s:%21Ld\n", #F, (long long)p->F) -#define __PN(F) \ - SEQ_printf(m, "%-35s:%14Ld.%06ld\n", #F, SPLIT_NS((long long)F)) -#define PN(F) \ - SEQ_printf(m, "%-35s:%14Ld.%06ld\n", #F, SPLIT_NS((long long)p->F)) - - PN(se.exec_start); - PN(se.vruntime); - PN(se.sum_exec_runtime); - PN(se.avg_overlap); - PN(se.avg_wakeup); - - nr_switches = p->nvcsw + p->nivcsw; - -#ifdef CONFIG_SCHEDSTATS - PN(se.wait_start); - PN(se.sleep_start); - PN(se.block_start); - PN(se.sleep_max); - PN(se.block_max); - PN(se.exec_max); - PN(se.slice_max); - PN(se.wait_max); - PN(se.wait_sum); - P(se.wait_count); - P(sched_info.bkl_count); - P(se.nr_migrations); - P(se.nr_migrations_cold); - P(se.nr_failed_migrations_affine); - P(se.nr_failed_migrations_running); - P(se.nr_failed_migrations_hot); - P(se.nr_forced_migrations); - P(se.nr_forced2_migrations); - P(se.nr_wakeups); - P(se.nr_wakeups_sync); - P(se.nr_wakeups_migrate); - P(se.nr_wakeups_local); - P(se.nr_wakeups_remote); - P(se.nr_wakeups_affine); - P(se.nr_wakeups_affine_attempts); - P(se.nr_wakeups_passive); - P(se.nr_wakeups_idle); - - { - u64 avg_atom, avg_per_cpu; - - avg_atom = p->se.sum_exec_runtime; - if (nr_switches) - do_div(avg_atom, nr_switches); - else - avg_atom = -1LL; - - avg_per_cpu = p->se.sum_exec_runtime; - if (p->se.nr_migrations) { - avg_per_cpu = div64_u64(avg_per_cpu, - p->se.nr_migrations); - } else { - avg_per_cpu = -1LL; - } - - __PN(avg_atom); - __PN(avg_per_cpu); - } -#endif - __P(nr_switches); - SEQ_printf(m, "%-35s:%21Ld\n", - "nr_voluntary_switches", (long long)p->nvcsw); - SEQ_printf(m, "%-35s:%21Ld\n", - "nr_involuntary_switches", (long long)p->nivcsw); - - P(se.load.weight); - P(policy); - P(prio); -#undef PN -#undef __PN -#undef P -#undef __P - - { - unsigned int this_cpu = raw_smp_processor_id(); - u64 t0, t1; - - t0 = cpu_clock(this_cpu); - t1 = cpu_clock(this_cpu); - SEQ_printf(m, "%-35s:%21Ld\n", - "clock-delta", (long long)(t1-t0)); - } -} - -void proc_sched_set_task(struct task_struct *p) -{ -#ifdef CONFIG_SCHEDSTATS - p->se.wait_max = 0; - p->se.wait_sum = 0; - p->se.wait_count = 0; - p->se.sleep_max = 0; - p->se.sum_sleep_runtime = 0; - p->se.block_max = 0; - p->se.exec_max = 0; - p->se.slice_max = 0; - p->se.nr_migrations = 0; - p->se.nr_migrations_cold = 0; - p->se.nr_failed_migrations_affine = 0; - p->se.nr_failed_migrations_running = 0; - p->se.nr_failed_migrations_hot = 0; - p->se.nr_forced_migrations = 0; - p->se.nr_forced2_migrations = 0; - p->se.nr_wakeups = 0; - p->se.nr_wakeups_sync = 0; - p->se.nr_wakeups_migrate = 0; - p->se.nr_wakeups_local = 0; - p->se.nr_wakeups_remote = 0; - p->se.nr_wakeups_affine = 0; - p->se.nr_wakeups_affine_attempts = 0; - p->se.nr_wakeups_passive = 0; - p->se.nr_wakeups_idle = 0; - p->sched_info.bkl_count = 0; -#endif - p->se.sum_exec_runtime = 0; - p->se.prev_sum_exec_runtime = 0; - p->nvcsw = 0; - p->nivcsw = 0; -} Index: linux-2.6.30-bfs/include/linux/ioprio.h =================================================================== --- linux-2.6.30-bfs.orig/include/linux/ioprio.h 2009-09-03 19:50:51.806053711 +1000 +++ linux-2.6.30-bfs/include/linux/ioprio.h 2009-09-03 19:51:10.954056511 +1000 @@ -73,7 +73,7 @@ */ static inline int task_nice_ioclass(struct task_struct *task) { - if (task->policy == SCHED_IDLE) + if (task->policy == SCHED_IDLEPRIO) return IOPRIO_CLASS_IDLE; else if (task->policy == SCHED_FIFO || task->policy == SCHED_RR) return IOPRIO_CLASS_RT;
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