diff --git a/[refs] b/[refs]
index 4614d46ee3d4..a46aae3fb352 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 5e2bf0142231194d36fdc9596b36a261ed2b9fe7
+refs/heads/master: 8c7577637ca31385e92769a77e2ab5b428e8b99c
diff --git a/trunk/mm/memcontrol.c b/trunk/mm/memcontrol.c
index 31ab9c3f0178..b659260c56ad 100644
--- a/trunk/mm/memcontrol.c
+++ b/trunk/mm/memcontrol.c
@@ -4507,6 +4507,12 @@ static void mem_cgroup_usage_unregister_event(struct cgroup *cgrp,
 swap_buffers:
 	/* Swap primary and spare array */
 	thresholds->spare = thresholds->primary;
+	/* If all events are unregistered, free the spare array */
+	if (!new) {
+		kfree(thresholds->spare);
+		thresholds->spare = NULL;
+	}
+
 	rcu_assign_pointer(thresholds->primary, new);
 
 	/* To be sure that nobody uses thresholds */