File libvirt-qemu-Drop-qemuDomainMemoryLimit.patch of Package libvirt

From ea988d07c0d3ffb4a36102c71e859d75143a0829 Mon Sep 17 00:00:00 2001
Message-Id: <ea988d07c0d3ffb4a36102c71e859d75143a0829.1380730269.git.jdenemar@redhat.com>
From: Michal Privoznik <mprivozn@redhat.com>
Date: Mon, 30 Sep 2013 20:14:53 +0200
Subject: [PATCH] qemu: Drop qemuDomainMemoryLimit

https://bugzilla.redhat.com/show_bug.cgi?id=1013758

This function is to guess the correct limit for maximal memory
usage by qemu for given domain. This can never be guessed
correctly, not to mention all the pains and sleepless nights this
code has caused. Once somebody discovers algorithm to solve the
Halting Problem, we can compute the limit algorithmically. But
till then, this code should never see the light of the release
again.
(cherry picked from commit 16bcb3b61675a88bff00317336b9610080c31000)

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>

Conflicts:
	src/qemu/qemu_cgroup.c: Context
	src/qemu/qemu_domain.c: Context
	src/qemu/qemu_domain.h: Context
	src/qemu/qemu_hotplug.c: Context
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
---
 src/qemu/qemu_cgroup.c  |  3 +--
 src/qemu/qemu_command.c |  2 +-
 src/qemu/qemu_domain.c  | 32 --------------------------------
 src/qemu/qemu_domain.h  |  1 -
 4 files changed, 2 insertions(+), 36 deletions(-)

diff --git a/src/qemu/qemu_cgroup.c b/src/qemu/qemu_cgroup.c
index e4a5452..f6f9d8c 100644
--- a/src/qemu/qemu_cgroup.c
+++ b/src/qemu/qemu_cgroup.c
@@ -343,8 +343,7 @@ int qemuSetupCgroup(struct qemud_driver *driver,
     }
 
     if (qemuCgroupControllerActive(driver, VIR_CGROUP_CONTROLLER_MEMORY)) {
-        rc = virCgroupSetMemoryHardLimit(cgroup,
-                                         qemuDomainMemoryLimit(vm->def));
+        rc = virCgroupSetMemoryHardLimit(cgroup, vm->def->mem.hard_limit);
         if (rc != 0) {
             virReportSystemError(-rc,
                                  _("Unable to set memory hard limit for domain %s"),
diff --git a/src/qemu/qemu_command.c b/src/qemu/qemu_command.c
index 7cdbac7..628f8d4 100644
--- a/src/qemu/qemu_command.c
+++ b/src/qemu/qemu_command.c
@@ -6958,7 +6958,7 @@ qemuBuildCommandLine(virConnectPtr conn,
     }
 
     if (mlock)
-        virCommandSetMaxMemLock(cmd, qemuDomainMemoryLimit(def) * 1024);
+        virCommandSetMaxMemLock(cmd, def->mem.hard_limit * 1024);
 
     return cmd;
 
diff --git a/src/qemu/qemu_domain.c b/src/qemu/qemu_domain.c
index faf4a73..5c577c5 100644
--- a/src/qemu/qemu_domain.c
+++ b/src/qemu/qemu_domain.c
@@ -2031,35 +2031,3 @@ qemuDomainDetermineDiskChain(struct qemud_driver *driver,
     return 0;
 }
 
-
-unsigned long long
-qemuDomainMemoryLimit(virDomainDefPtr def)
-{
-    unsigned long long mem;
-    int i;
-
-    if (def->mem.hard_limit) {
-        mem = def->mem.hard_limit;
-    } else {
-        /* If there is no hard_limit set, compute a reasonable one to avoid
-         * system thrashing caused by exploited qemu.  A 'reasonable
-         * limit' has been chosen:
-         *     (1 + k) * (domain memory + total video memory) + (32MB for
-         *     cache per each disk) + F
-         * where k = 0.5 and F = 200MB.  The cache for disks is important as
-         * kernel cache on the host side counts into the RSS limit.
-         *
-         * Technically, the disk cache does not have to be included in
-         * RLIMIT_MEMLOCK but it doesn't hurt as it's just an upper limit and
-         * it makes this function and its usage simpler.
-         */
-        mem = def->mem.max_balloon;
-        for (i = 0; i < def->nvideos; i++)
-            mem += def->videos[i]->vram;
-        mem *= 1.5;
-        mem += def->ndisks * 32768;
-        mem += 204800;
-    }
-
-    return mem;
-}
diff --git a/src/qemu/qemu_domain.h b/src/qemu/qemu_domain.h
index 5056d8c..c010a3e 100644
--- a/src/qemu/qemu_domain.h
+++ b/src/qemu/qemu_domain.h
@@ -364,6 +364,5 @@ void qemuDomainCleanupRemove(virDomainObjPtr vm,
 void qemuDomainCleanupRun(struct qemud_driver *driver,
                           virDomainObjPtr vm);
 
-unsigned long long qemuDomainMemoryLimit(virDomainDefPtr def);
 
 #endif /* __QEMU_DOMAIN_H__ */
-- 
1.8.3.2