From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754027Ab2I0R4u (ORCPT ); Thu, 27 Sep 2012 13:56:50 -0400 Received: from cantor2.suse.de ([195.135.220.15]:56239 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753123Ab2I0R4s (ORCPT ); Thu, 27 Sep 2012 13:56:48 -0400 Date: Thu, 27 Sep 2012 19:56:43 +0200 From: Michal Hocko To: Tejun Heo Cc: Glauber Costa , Mel Gorman , linux-kernel@vger.kernel.org, cgroups@vger.kernel.org, kamezawa.hiroyu@jp.fujitsu.com, devel@openvz.org, linux-mm@kvack.org, Suleiman Souhlal , Frederic Weisbecker , David Rientjes , Johannes Weiner Subject: Re: [PATCH v3 04/13] kmem accounting basic infrastructure Message-ID: <20120927175643.GA7777@dhcp22.suse.cz> References: <50637298.2090904@parallels.com> <20120926221046.GA10453@mtj.dyndns.org> <506381B2.2060806@parallels.com> <20120926224235.GB10453@mtj.dyndns.org> <50638793.7060806@parallels.com> <20120926230807.GC10453@mtj.dyndns.org> <20120927142822.GG3429@suse.de> <20120927144942.GB4251@mtj.dyndns.org> <50646977.40300@parallels.com> <20120927174605.GA2713@localhost> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20120927174605.GA2713@localhost> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu 27-09-12 10:46:05, Tejun Heo wrote: [...] > > > The part I nacked is enabling kmemcg on a populated cgroup and then > > > starting accounting from then without any apparent indication that any > > > past allocation hasn't been considered. You end up with numbers which > > > nobody can't tell what they really mean and there's no mechanism to > > > guarantee any kind of ordering between populating the cgroup and > > > configuring it and there's *no* way to find out what happened > > > afterwards neither. This is properly crazy and definitely deserves a > > > nack. > > > > > > > Mel suggestion of not allowing this to happen once the cgroup has tasks > > takes care of this, and is something I thought of myself. > > You mean Michal's? It should also disallow switching if there are > children cgroups, right? Right. -- Michal Hocko SUSE Labs From mboxrd@z Thu Jan 1 00:00:00 1970 From: Michal Hocko Subject: Re: [PATCH v3 04/13] kmem accounting basic infrastructure Date: Thu, 27 Sep 2012 19:56:43 +0200 Message-ID: <20120927175643.GA7777@dhcp22.suse.cz> References: <50637298.2090904@parallels.com> <20120926221046.GA10453@mtj.dyndns.org> <506381B2.2060806@parallels.com> <20120926224235.GB10453@mtj.dyndns.org> <50638793.7060806@parallels.com> <20120926230807.GC10453@mtj.dyndns.org> <20120927142822.GG3429@suse.de> <20120927144942.GB4251@mtj.dyndns.org> <50646977.40300@parallels.com> <20120927174605.GA2713@localhost> Mime-Version: 1.0 Return-path: Content-Disposition: inline In-Reply-To: <20120927174605.GA2713@localhost> Sender: owner-linux-mm@kvack.org List-ID: Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Tejun Heo Cc: Glauber Costa , Mel Gorman , linux-kernel@vger.kernel.org, cgroups@vger.kernel.org, kamezawa.hiroyu@jp.fujitsu.com, devel@openvz.org, linux-mm@kvack.org, Suleiman Souhlal , Frederic Weisbecker , David Rientjes , Johannes Weiner On Thu 27-09-12 10:46:05, Tejun Heo wrote: [...] > > > The part I nacked is enabling kmemcg on a populated cgroup and then > > > starting accounting from then without any apparent indication that any > > > past allocation hasn't been considered. You end up with numbers which > > > nobody can't tell what they really mean and there's no mechanism to > > > guarantee any kind of ordering between populating the cgroup and > > > configuring it and there's *no* way to find out what happened > > > afterwards neither. This is properly crazy and definitely deserves a > > > nack. > > > > > > > Mel suggestion of not allowing this to happen once the cgroup has tasks > > takes care of this, and is something I thought of myself. > > You mean Michal's? It should also disallow switching if there are > children cgroups, right? Right. -- 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