From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752002Ab2I0Mke (ORCPT ); Thu, 27 Sep 2012 08:40:34 -0400 Received: from cantor2.suse.de ([195.135.220.15]:40314 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751013Ab2I0Mkd (ORCPT ); Thu, 27 Sep 2012 08:40:33 -0400 Date: Thu, 27 Sep 2012 14:40:31 +0200 From: Michal Hocko To: Glauber Costa Cc: Tejun Heo , 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 , Mel Gorman , David Rientjes , Johannes Weiner Subject: Re: [PATCH v3 04/13] kmem accounting basic infrastructure Message-ID: <20120927124031.GC29104@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> <50638DBB.4000002@parallels.com> <20120926233334.GD10453@mtj.dyndns.org> <20120927121558.GB29104@dhcp22.suse.cz> <506444A7.5060303@parallels.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <506444A7.5060303@parallels.com> 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 16:20:55, Glauber Costa wrote: > On 09/27/2012 04:15 PM, Michal Hocko wrote: > > On Wed 26-09-12 16:33:34, Tejun Heo wrote: > > [...] > >>>> So, this seems properly crazy to me at the similar level of > >>>> use_hierarchy fiasco. I'm gonna NACK on this. > >>> > >>> As I said: all use cases I particularly care about are covered by a > >>> global switch. > >>> > >>> I am laying down my views because I really believe they make more sense. > >>> But at some point, of course, I'll shut up if I believe I am a lone voice. > >>> > >>> I believe it should still be good to hear from mhocko and kame, but from > >>> your point of view, would all the rest, plus the introduction of a > >>> global switch make it acceptable to you? > >> > >> The only thing I'm whining about is per-node switch + silently > >> ignoring past accounting, so if those two are solved, I think I'm > >> pretty happy with the rest. > > > > I think that per-group "switch" is not nice as well but if we make it > > hierarchy specific (which I am proposing for quite some time) and do not > > let enable accounting for a group with tasks then we get both > > flexibility and reasonable semantic. A global switch sounds too coars to > > me and it really not necessary. > > > > Would this work with you? > > > > How exactly would that work? AFAIK, we have a single memcg root, we > can't have multiple memcg hierarchies in a system. Am I missing something? Well root is so different that we could consider the first level as the real roots for hierarchies. -- Michal Hocko SUSE Labs