From: Oleg Nesterov <oleg@redhat.com>
Date: Tue, 10 Aug 2010 00:18:43 +0000 (-0700)
Subject: oom: check PF_KTHREAD instead of !mm to skip kthreads
X-Git-Url: http://git.efficios.com/?a=commitdiff_plain;h=455c0e5fb03b67fa62bd12e3abe3fa484b9960c5;p=deliverable%2Flinux.git

oom: check PF_KTHREAD instead of !mm to skip kthreads

select_bad_process() thinks a kernel thread can't have ->mm != NULL, this
is not true due to use_mm().

Change the code to check PF_KTHREAD.

Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: David Rientjes <rientjes@google.com>
Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---

diff --git a/mm/oom_kill.c b/mm/oom_kill.c
index 709aedfaa014..7c0dc414dba8 100644
--- a/mm/oom_kill.c
+++ b/mm/oom_kill.c
@@ -256,14 +256,11 @@ static struct task_struct *select_bad_process(unsigned long *ppoints,
 	for_each_process(p) {
 		unsigned long points;
 
-		/*
-		 * skip kernel threads and tasks which have already released
-		 * their mm.
-		 */
+		/* skip tasks that have already released their mm */
 		if (!p->mm)
 			continue;
-		/* skip the init task */
-		if (is_global_init(p))
+		/* skip the init task and kthreads */
+		if (is_global_init(p) || (p->flags & PF_KTHREAD))
 			continue;
 		if (mem && !task_in_mem_cgroup(p, mem))
 			continue;