diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index fb62b43..f0dc076 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -2202,7 +2202,7 @@
 }
 #endif
 
-static struct cgroup_subsys_state *
+static struct cgroup_subsys_state * __ref
 mem_cgroup_create(struct cgroup_subsys *ss, struct cgroup *cont)
 {
 	struct mem_cgroup *mem, *parent;