On Mon, Aug 01, 2016 at 05:24:54PM +0200, Michal Hocko wrote: > @@ -2564,7 +2559,13 @@ unsigned long mem_cgroup_soft_limit_reclaim(pg_data_t *pgdat, int order, > return 0; > > mctz = soft_limit_tree_node(pgdat->node_id); > - if (soft_limit_tree_empty(mctz)) > + > + /* > + * Do not even bother to check the largest node if the node root > + * is empty. Do it lockless to prevent lock bouncing. Races > + * are acceptable as soft limit is best effort anyway. > + */ > + if (RB_EMPTY_ROOT(&mctz->rb_root)) > return 0; Other than that, looks good. Please retain my Acked-by: Johannes Weiner <hannes@xxxxxxxxxxx> in version 2. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx"> email@xxxxxxxxx </a>