1 files changed, 6 insertions, 2 deletions

diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index e2f46ba37f72..aa95591c1430 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -4845,12 +4845,16 @@ static int __init cgroup_wq_init(void)
         /*
          * There isn't much point in executing destruction path in
          * parallel.  Good chunk is serialized with cgroup_mutex anyway.
-         * Use 1 for @max_active.
+         *
+         * XXX: Must be ordered to make sure parent is offlined after
+         * children.  The ordering requirement is for memcg where a
+         * parent's offline may wait for a child's leading to deadlock.  In
+         * the long term, this should be fixed from memcg side.
          *
          * We would prefer to do this in cgroup_init() above, but that
          * is called before init_workqueues(): so leave this until after.
          */
-        cgroup_destroy_wq = alloc_workqueue("cgroup_destroy", 0, 1);
+        cgroup_destroy_wq = alloc_ordered_workqueue("cgroup_destroy", 0);
         BUG_ON(!cgroup_destroy_wq);
 
         /*