From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx106.postini.com [74.125.245.106]) by kanga.kvack.org (Postfix) with SMTP id B98116B0006 for ; Wed, 20 Mar 2013 03:03:37 -0400 (EDT) Message-ID: <51495F67.3040009@parallels.com> Date: Wed, 20 Mar 2013 11:04:07 +0400 From: Glauber Costa MIME-Version: 1.0 Subject: Re: [PATCH v2 2/5] memcg: provide root figures from system totals References: <1362489058-3455-1-git-send-email-glommer@parallels.com> <1362489058-3455-3-git-send-email-glommer@parallels.com> <20130319124650.GE7869@dhcp22.suse.cz> In-Reply-To: <20130319124650.GE7869@dhcp22.suse.cz> Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Michal Hocko Cc: linux-mm@kvack.org, cgroups@vger.kernel.org, Tejun Heo , Andrew Morton , kamezawa.hiroyu@jp.fujitsu.com, handai.szj@gmail.com, anton.vorontsov@linaro.org, Johannes Weiner , Mel Gorman On 03/19/2013 04:46 PM, Michal Hocko wrote: > On Tue 05-03-13 17:10:55, Glauber Costa wrote: >> For the root memcg, there is no need to rely on the res_counters if hierarchy >> is enabled The sum of all mem cgroups plus the tasks in root itself, is >> necessarily the amount of memory used for the whole system. Since those figures >> are already kept somewhere anyway, we can just return them here, without too >> much hassle. >> >> Limit and soft limit can't be set for the root cgroup, so they are left at >> RESOURCE_MAX. Failcnt is left at 0, because its actual meaning is how many >> times we failed allocations due to the limit being hit. We will fail >> allocations in the root cgroup, but the limit will never the reason. > > I do not like this very much to be honest. It just adds more hackery... > Why cannot we simply not account if nr_cgroups == 1 and move relevant > global counters to the root at the moment when a first group is > created? > The patch aims at reducing an overhead when there there are no other > groups, right? > You've already noted yourself that this is done in a later patch. -- 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