From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx143.postini.com [74.125.245.143]) by kanga.kvack.org (Postfix) with SMTP id F06D06B000A for ; Tue, 5 Mar 2013 08:11:02 -0500 (EST) From: Glauber Costa Subject: [PATCH v2 5/5] memcg: do not walk all the way to the root for memcg Date: Tue, 5 Mar 2013 17:10:58 +0400 Message-Id: <1362489058-3455-6-git-send-email-glommer@parallels.com> In-Reply-To: <1362489058-3455-1-git-send-email-glommer@parallels.com> References: <1362489058-3455-1-git-send-email-glommer@parallels.com> Sender: owner-linux-mm@kvack.org List-ID: To: linux-mm@kvack.org Cc: cgroups@vger.kernel.org, Tejun Heo , Andrew Morton , Michal Hocko , kamezawa.hiroyu@jp.fujitsu.com, handai.szj@gmail.com, anton.vorontsov@linaro.org, Glauber Costa , Johannes Weiner , Mel Gorman Since the root is special anyway, and we always get its figures from global counters anyway, there is no make all cgroups its descendants, wrt res_counters. The sad effect of doing that is that we need to lock the root for all allocations, since it is a common ancestor of everybody. Not having the root as a common ancestor should lead to better scalability for not-uncommon case of tasks in the cgroup being node-bound to different nodes in NUMA systems. Signed-off-by: Glauber Costa CC: Michal Hocko CC: Kamezawa Hiroyuki CC: Johannes Weiner CC: Mel Gorman CC: Andrew Morton --- mm/memcontrol.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 6019a32..252dc00 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -6464,7 +6464,7 @@ mem_cgroup_css_online(struct cgroup *cont) memcg->oom_kill_disable = parent->oom_kill_disable; memcg->swappiness = mem_cgroup_swappiness(parent); - if (parent->use_hierarchy) { + if (parent && !mem_cgroup_is_root(parent) && parent->use_hierarchy) { res_counter_init(&memcg->res, &parent->res); res_counter_init(&memcg->memsw, &parent->memsw); res_counter_init(&memcg->kmem, &parent->kmem); -- 1.8.1.2 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org