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authorKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>2010-08-10 18:03:00 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2010-08-11 08:59:19 -0700
commit158e0a2d1b3cffed8b46cbc56393a1394672ef79 (patch)
treea044d53137609fdfc8c1afdde366b3e205c96eda
parent73045c47b6facbdf4656e6763c8cb469de4337e2 (diff)
downloadvexpress-lsk-158e0a2d1b3cffed8b46cbc56393a1394672ef79.tar.gz
memcg: use find_lock_task_mm() in memory cgroups oom
When the OOM killer scans task, it check a task is under memcg or not when it's called via memcg's context. But, as Oleg pointed out, a thread group leader may have NULL ->mm and task_in_mem_cgroup() may do wrong decision. We have to use find_lock_task_mm() in memcg as generic OOM-Killer does. Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: Balbir Singh <balbir@linux.vnet.ibm.com> Reviewed-by: Minchan Kim <minchan.kim@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--include/linux/oom.h2
-rw-r--r--mm/memcontrol.c10
-rw-r--r--mm/oom_kill.c2
3 files changed, 10 insertions, 4 deletions
diff --git a/include/linux/oom.h b/include/linux/oom.h
index f209b683e11..5e3aa8311c5 100644
--- a/include/linux/oom.h
+++ b/include/linux/oom.h
@@ -66,6 +66,8 @@ static inline void oom_killer_enable(void)
extern unsigned long badness(struct task_struct *p, struct mem_cgroup *mem,
const nodemask_t *nodemask, unsigned long uptime);
+extern struct task_struct *find_lock_task_mm(struct task_struct *p);
+
/* sysctls */
extern int sysctl_oom_dump_tasks;
extern int sysctl_oom_kill_allocating_task;
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index ea5f5edf00b..f52b0a1861c 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -47,6 +47,7 @@
#include <linux/mm_inline.h>
#include <linux/page_cgroup.h>
#include <linux/cpu.h>
+#include <linux/oom.h>
#include "internal.h"
#include <asm/uaccess.h>
@@ -838,10 +839,13 @@ int task_in_mem_cgroup(struct task_struct *task, const struct mem_cgroup *mem)
{
int ret;
struct mem_cgroup *curr = NULL;
+ struct task_struct *p;
- task_lock(task);
- curr = try_get_mem_cgroup_from_mm(task->mm);
- task_unlock(task);
+ p = find_lock_task_mm(task);
+ if (!p)
+ return 0;
+ curr = try_get_mem_cgroup_from_mm(p->mm);
+ task_unlock(p);
if (!curr)
return 0;
/*
diff --git a/mm/oom_kill.c b/mm/oom_kill.c
index d3def05a33d..5014e50644d 100644
--- a/mm/oom_kill.c
+++ b/mm/oom_kill.c
@@ -106,7 +106,7 @@ static void boost_dying_task_prio(struct task_struct *p,
* pointer. Return p, or any of its subthreads with a valid ->mm, with
* task_lock() held.
*/
-static struct task_struct *find_lock_task_mm(struct task_struct *p)
+struct task_struct *find_lock_task_mm(struct task_struct *p)
{
struct task_struct *t = p;