From 4f903761197f2f44488b7c86566e5d3cc4a639de Mon Sep 17 00:00:00 2001
From: David Rientjes <rientjes@google.com>
Date: Thu, 12 Jan 2012 17:18:52 -0800
Subject: [PATCH] --- yaml --- r: 284384 b: refs/heads/master c:
 de077d222d5ca6108cab119a09593344c12100ab h: refs/heads/master v: v3

---
 [refs]                |  2 +-
 trunk/mm/memcontrol.c | 19 +++++++++++++++----
 2 files changed, 16 insertions(+), 5 deletions(-)

diff --git a/[refs] b/[refs]
index 5596d6a6f368..5d98e33f8e54 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: c3cecc683446ad54ca587d7123bd3ce94bd7b8e1
+refs/heads/master: de077d222d5ca6108cab119a09593344c12100ab
diff --git a/trunk/mm/memcontrol.c b/trunk/mm/memcontrol.c
index 2a1f7847b6ad..7bc30707d0c6 100644
--- a/trunk/mm/memcontrol.c
+++ b/trunk/mm/memcontrol.c
@@ -1238,10 +1238,21 @@ int task_in_mem_cgroup(struct task_struct *task, const struct mem_cgroup *memcg)
 	struct task_struct *p;
 
 	p = find_lock_task_mm(task);
-	if (!p)
-		return 0;
-	curr = try_get_mem_cgroup_from_mm(p->mm);
-	task_unlock(p);
+	if (p) {
+		curr = try_get_mem_cgroup_from_mm(p->mm);
+		task_unlock(p);
+	} else {
+		/*
+		 * All threads may have already detached their mm's, but the oom
+		 * killer still needs to detect if they have already been oom
+		 * killed to prevent needlessly killing additional tasks.
+		 */
+		task_lock(task);
+		curr = mem_cgroup_from_task(task);
+		if (curr)
+			css_get(&curr->css);
+		task_unlock(task);
+	}
 	if (!curr)
 		return 0;
 	/*