From 30e2b41f20b6238f51e7cffb879c7a0f0073f5fe Mon Sep 17 00:00:00 2001
From: Andrey Vagin <avagin@openvz.org>
Date: Tue, 22 Mar 2011 16:30:11 -0700
Subject: [PATCH] oom: skip zombies when iterating tasklist
We shouldn't defer oom killing if a thread has already detached its ->mm
and still has TIF_MEMDIE set. Memory needs to be freed, so find kill
other threads that pin the same ->mm or find another task to kill.
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: David Rientjes <rientjes@google.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: <stable@kernel.org> [2.6.38.x]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
mm/oom_kill.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/mm/oom_kill.c b/mm/oom_kill.c
index b5a7b5f46e7a..d7f345e47e73 100644
--- a/mm/oom_kill.c
+++ b/mm/oom_kill.c
@@ -299,6 +299,8 @@ static struct task_struct *select_bad_process(unsigned int *ppoints,
do_each_thread(g, p) {
unsigned int points;
+ if (!p->mm)
+ continue;
if (oom_unkillable_task(p, mem, nodemask))
continue;
@@ -324,7 +326,7 @@ static struct task_struct *select_bad_process(unsigned int *ppoints,
* the process of exiting and releasing its resources.
* Otherwise we could get an easy OOM deadlock.
*/
- if ((p->flags & PF_EXITING) && p->mm) {
+ if (p->flags & PF_EXITING) {
if (p != current)
return ERR_PTR(-1UL);