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 <[email protected]>
in version 2.
