From e42b5369142a30183a4bdc173acbdc1b123a63a3 Mon Sep 17 00:00:00 2001
From: Glauber Costa <glommer@parallels.com>
Date: Wed, 20 Feb 2013 13:14:46 +1100
Subject: [PATCH] memcg: fast hierarchy-aware child test fix

Cc: Glauber Costa <glommer@parallels.com>
Cc: Hiroyuki Kamezawa <kamezawa.hiroyuki@gmail.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Michal Hocko <mhocko@suse.cz>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---
 mm/memcontrol.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 79ae372e6e8c..2bc3fbe93154 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -5734,8 +5734,7 @@ static int mem_cgroup_oom_control_write(struct cgroup *cgrp,
 
 	cgroup_lock();
 	/* oom-kill-disable is a flag for subhierarchy. */
-	if ((parent->use_hierarchy) ||
-	    (memcg->use_hierarchy && !list_empty(&cgrp->children))) {
+	if ((parent->use_hierarchy) || memcg_has_children(memcg)) {
 		cgroup_unlock();
 		return -EINVAL;
 	}
-- 
2.39.5