File 19543-conring-size-param.patch of Package xen
# HG changeset patch
# User Keir Fraser <keir.fraser@citrix.com>
# Date 1239717147 -3600
# Node ID 81d6b5762c4036965f4e92b226a93e6c0925bd92
# Parent cbaae05c2902739b789b8aa21ddedd0bdbb1ebb0
New option conring_size= to allow larger console ring.
Signed-off-by: Keir Fraser <keir.fraser@citrix.com>
# HG changeset patch
# User Keir Fraser <keir.fraser@citrix.com>
# Date 1251708665 -3600
# Node ID bff9f3e5ad940845a02702558129e5db815f1fd5
# Parent eae7b5ee789738528dac5c309aabd6e316005e0f
Adjust non-default sized console ring allocation
Using xmalloc() for objects that are guaranteed to be at least as
large as a page is wasteful, as it will always result in more (here:
double the amount) being allocated.
The other adjustments are more cosmetic:
- Updating conring and conring_size can be done so NMI/MCE generated
messages don't use the new (larger) size with the old (smaller)
buffer.
- The size printed can be in KiB (for the value to be easier to grasp)
since it is always a multiple of the default of 16KiB.
Signed-off-by: Jan Beulich <jbeulich@novell.com>
--- a/xen/arch/ia64/xen/xensetup.c
+++ b/xen/arch/ia64/xen/xensetup.c
@@ -388,7 +388,6 @@ void __init start_kernel(void)
ns16550_init(0, &ns16550_com1);
ns16550_init(1, &ns16550_com2);
}
- serial_init_preirq();
#ifdef CONFIG_VGA
/* Plug in a default VGA mode */
@@ -404,7 +403,7 @@ void __init start_kernel(void)
ia64_boot_param->console_info.num_cols;
#endif
- init_console();
+ console_init_preirq();
if (running_on_sim || ia64_boot_param->domain_start == 0 ||
ia64_boot_param->domain_size == 0) {
@@ -668,7 +667,7 @@ printk("num_online_cpus=%d, max_cpus=%d\
ns16550_init(0, &ns16550_com1);
}
}
- serial_init_postirq();
+ console_init_postirq();
}
expose_p2m_init();
--- a/xen/arch/x86/setup.c
+++ b/xen/arch/x86/setup.c
@@ -464,9 +464,7 @@ void __init __start_xen(unsigned long mb
ns16550.io_base = 0x2f8;
ns16550.irq = 3;
ns16550_init(1, &ns16550);
- serial_init_preirq();
-
- init_console();
+ console_init_preirq();
printk("Command line: %s\n", cmdline);
@@ -960,7 +958,7 @@ void __init __start_xen(unsigned long mb
initialize_keytable();
- serial_init_postirq();
+ console_init_postirq();
BUG_ON(!local_irq_is_enabled());
--- a/xen/drivers/char/console.c
+++ b/xen/drivers/char/console.c
@@ -58,10 +58,16 @@ boolean_param("console_to_ring", opt_con
static int opt_console_timestamps;
boolean_param("console_timestamps", opt_console_timestamps);
-#define CONRING_SIZE 16384
-#define CONRING_IDX_MASK(i) ((i)&(CONRING_SIZE-1))
-static char conring[CONRING_SIZE];
-static uint32_t conringc, conringp;
+/* conring_size: allows a large console ring than default (16kB). */
+static uint32_t opt_conring_size;
+static void parse_conring_size(char *s)
+{ opt_conring_size = parse_size_and_unit(s, NULL); }
+custom_param("conring_size", parse_conring_size);
+
+#define _CONRING_SIZE 16384
+#define CONRING_IDX_MASK(i) ((i)&(conring_size-1))
+static char _conring[_CONRING_SIZE], *conring = _conring;
+static uint32_t conring_size = _CONRING_SIZE, conringc, conringp;
static int sercon_handle = -1;
@@ -178,8 +184,8 @@ static void putchar_console_ring(int c)
{
ASSERT(spin_is_locked(&console_lock));
conring[CONRING_IDX_MASK(conringp++)] = c;
- if ( (uint32_t)(conringp - conringc) > CONRING_SIZE )
- conringc = conringp - CONRING_SIZE;
+ if ( (uint32_t)(conringp - conringc) > conring_size )
+ conringc = conringp - conring_size;
}
long read_console_ring(struct xen_sysctl_readconsole *op)
@@ -199,8 +205,8 @@ long read_console_ring(struct xen_sysctl
{
idx = CONRING_IDX_MASK(c);
len = conringp - c;
- if ( (idx + len) > CONRING_SIZE )
- len = CONRING_SIZE - idx;
+ if ( (idx + len) > conring_size )
+ len = conring_size - idx;
if ( (sofar + len) > max )
len = max - sofar;
if ( copy_to_guest_offset(str, sofar, &conring[idx], len) )
@@ -212,8 +218,8 @@ long read_console_ring(struct xen_sysctl
if ( op->clear )
{
spin_lock_irq(&console_lock);
- if ( (uint32_t)(conringp - c) > CONRING_SIZE )
- conringc = conringp - CONRING_SIZE;
+ if ( (uint32_t)(conringp - c) > conring_size )
+ conringc = conringp - conring_size;
else
conringc = c;
spin_unlock_irq(&console_lock);
@@ -544,10 +550,12 @@ void printk(const char *fmt, ...)
local_irq_restore(flags);
}
-void __init init_console(void)
+void __init console_init_preirq(void)
{
char *p;
+ serial_init_preirq();
+
/* Where should console output go? */
for ( p = opt_console; p != NULL; p = strchr(p, ',') )
{
@@ -587,6 +595,38 @@ void __init init_console(void)
}
}
+void __init console_init_postirq(void)
+{
+ char *ring;
+ unsigned int i;
+
+ serial_init_postirq();
+
+ /* Round size down to a power of two. */
+ while ( opt_conring_size & (opt_conring_size - 1) )
+ opt_conring_size &= opt_conring_size - 1;
+ if ( opt_conring_size < conring_size )
+ return;
+
+ ring = alloc_xenheap_pages(get_order_from_bytes(opt_conring_size));
+ if ( ring == NULL )
+ {
+ printk("Unable to allocate console ring of %u bytes.\n",
+ opt_conring_size);
+ return;
+ }
+
+ spin_lock_irq(&console_lock);
+ for ( i = conringc ; i != conringp; i++ )
+ ring[i & (opt_conring_size - 1)] = conring[i & (conring_size - 1)];
+ conring = ring;
+ wmb(); /* Allow users of console_force_unlock() to see larger buffer. */
+ conring_size = opt_conring_size;
+ spin_unlock_irq(&console_lock);
+
+ printk("Allocated console ring of %u KiB.\n", opt_conring_size >> 10);
+}
+
void __init console_endboot(void)
{
int i, j;
--- a/xen/include/xen/console.h
+++ b/xen/include/xen/console.h
@@ -14,7 +14,8 @@
struct xen_sysctl_readconsole;
long read_console_ring(struct xen_sysctl_readconsole *op);
-void init_console(void);
+void console_init_preirq(void);
+void console_init_postirq(void);
void console_endboot(void);
int console_has(const char *device);
