From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx171.postini.com [74.125.245.171]) by kanga.kvack.org (Postfix) with SMTP id CD5166B0005 for ; Tue, 19 Mar 2013 08:55:10 -0400 (EDT) Date: Tue, 19 Mar 2013 13:55:09 +0100 From: Michal Hocko Subject: Re: [PATCH v2 2/5] memcg: provide root figures from system totals Message-ID: <20130319125509.GF7869@dhcp22.suse.cz> References: <1362489058-3455-1-git-send-email-glommer@parallels.com> <1362489058-3455-3-git-send-email-glommer@parallels.com> <20130319124650.GE7869@dhcp22.suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20130319124650.GE7869@dhcp22.suse.cz> Sender: owner-linux-mm@kvack.org List-ID: To: Glauber Costa 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 Tue 19-03-13 13:46:50, 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? OK, it seems that the very next patch does what I was looking for. So why all the churn in this patch? Why do you want to make root even more special? [...] -- Michal Hocko SUSE Labs -- 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