From: Kirill A. Shutemov <kirill@shutemov.name>
Date: Thu, 7 Oct 2010 19:59:27 +0000 (-0700)
Subject: memcg: fix thresholds with use_hierarchy == 1
X-Git-Tag: v2.6.36-rc8~37
X-Git-Url: http://bbs.cooldavid.org/git/?p=net-next-2.6.git;a=commitdiff_plain;h=ad4ca5f4b70236dab5e457ff6567d36f75d2e7c5

memcg: fix thresholds with use_hierarchy == 1

We need to check parent's thresholds if parent has use_hierarchy == 1 to
be sure that parent's threshold events will be triggered even if parent
itself is not active (no MEM_CGROUP_EVENTS).

Signed-off-by: Kirill A. Shutemov <kirill@shutemov.name>
Reviewed-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 3eed583895a..9be3cf8a5da 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -3587,9 +3587,13 @@ unlock:
 
 static void mem_cgroup_threshold(struct mem_cgroup *memcg)
 {
-	__mem_cgroup_threshold(memcg, false);
-	if (do_swap_account)
-		__mem_cgroup_threshold(memcg, true);
+	while (memcg) {
+		__mem_cgroup_threshold(memcg, false);
+		if (do_swap_account)
+			__mem_cgroup_threshold(memcg, true);
+
+		memcg = parent_mem_cgroup(memcg);
+	}
 }
 
 static int compare_thresholds(const void *a, const void *b)