diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 09255ec8159c459624e66ee5ac17ca092d2fcd6b..fbb60b103e64b11021475a749b86da6f7eb7137e 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -3030,7 +3030,9 @@ int memcg_register_cache(struct mem_cgroup *memcg, struct kmem_cache *s,
 	if (memcg) {
 		s->memcg_params->memcg = memcg;
 		s->memcg_params->root_cache = root_cache;
-	}
+	} else
+		s->memcg_params->is_root_cache = true;
+
 	return 0;
 }