1 files changed, 14 insertions, 0 deletions

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 6115b2bbd6ea..f45e21ab9cea 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -6326,9 +6326,23 @@ static void mem_cgroup_invalidate_reclaim_iterators(struct mem_cgroup *memcg)
 static void mem_cgroup_css_offline(struct cgroup *cont)
 {
         struct mem_cgroup *memcg = mem_cgroup_from_cont(cont);
+        struct cgroup *iter;
 
         mem_cgroup_invalidate_reclaim_iterators(memcg);
+
+        /*
+         * This requires that offlining is serialized.  Right now that is
+         * guaranteed because css_killed_work_fn() holds the cgroup_mutex.
+         */
+        rcu_read_lock();
+        cgroup_for_each_descendant_post(iter, cont) {
+                rcu_read_unlock();
+                mem_cgroup_reparent_charges(mem_cgroup_from_cont(iter));
+                rcu_read_lock();
+        }
+        rcu_read_unlock();
         mem_cgroup_reparent_charges(memcg);
+
         mem_cgroup_destroy_all_caches(memcg);
 }