memcg: revise the position of threshold index while unregistering event

Index current_threshold should point to threshold just below or equal to
usage.  See below: http://www.spinics.net/lists/cgroups/msg00844.html

Signed-off-by: Sha Zhengju <handai.szj@taobao.com>
Reviewed-by: Kirill A. Shutemov <kirill@shutemov.name>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index c003c9940f5f7888c34bcfd86d44f17703352c1f..bbae7af36cc7cd3bec762d648db44f77628e67d4 100644 (file)
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -4695,7 +4695,7 @@ static void mem_cgroup_usage_unregister_event(struct cgroup *cgrp,
                        continue;
 
                new->entries[j] = thresholds->primary->entries[i];
-               if (new->entries[j].threshold < usage) {
+               if (new->entries[j].threshold <= usage) {
                        /*
                         * new->current_threshold will not be used
                         * until rcu_assign_pointer(), so it's safe to increment