From: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Date: Thu, 8 Jan 2009 02:08:13 +0000 (-0800)
Subject: memcg: hierarchy avoid unnecessary reclaim
X-Git-Tag: v2.6.29-rc1~116
X-Git-Url: http://pilppa.com/gitweb/?a=commitdiff_plain;h=670ec2f170301425fc4fdfa63d40652071fe85f6;p=linux-2.6-omap-h63xx.git

memcg: hierarchy avoid unnecessary reclaim

If hierarchy is not used, no tree-walk is necessary.

Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.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 964a70035e8..9b4993ee46b 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -606,6 +606,8 @@ static int mem_cgroup_hierarchical_reclaim(struct mem_cgroup *root_mem,
 	ret = try_to_free_mem_cgroup_pages(root_mem, gfp_mask, noswap);
 	if (mem_cgroup_check_under_limit(root_mem))
 		return 0;
+	if (!root_mem->use_hierarchy)
+		return ret;
 
 	next_mem = mem_cgroup_get_first_node(root_mem);