From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757952Ab2IEI6n (ORCPT ); Wed, 5 Sep 2012 04:58:43 -0400 Received: from mx2.parallels.com ([64.131.90.16]:60065 "EHLO mx2.parallels.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751328Ab2IEI6m (ORCPT ); Wed, 5 Sep 2012 04:58:42 -0400 Message-ID: <50471379.3060603@parallels.com> Date: Wed, 5 Sep 2012 12:55:21 +0400 From: Glauber Costa User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:15.0) Gecko/20120828 Thunderbird/15.0 MIME-Version: 1.0 To: Tejun Heo CC: , , , , , , , , Subject: Re: [RFC 0/5] forced comounts for cgroups. References: <1346768300-10282-1-git-send-email-glommer@parallels.com> <20120904214602.GA9092@dhcp-172-17-108-109.mtv.corp.google.com> <5047074D.1030104@parallels.com> <20120905081439.GC3195@dhcp-172-17-108-109.mtv.corp.google.com> <50470A87.1040701@parallels.com> <20120905082947.GD3195@dhcp-172-17-108-109.mtv.corp.google.com> <50470EBF.9070109@parallels.com> <20120905084740.GE3195@dhcp-172-17-108-109.mtv.corp.google.com> In-Reply-To: <20120905084740.GE3195@dhcp-172-17-108-109.mtv.corp.google.com> Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 09/05/2012 12:47 PM, Tejun Heo wrote: > Hello, Glauber. > > On Wed, Sep 05, 2012 at 12:35:11PM +0400, Glauber Costa wrote: >>> As long as cpuacct and cpu are separate, I think it makes sense to >>> assume that they at least could be at different granularity. >> >> If they are comounted, and more: forceably comounted, I don't see how to >> call them separate. At the very best, they are this way for >> compatibility purposes only, to lay a path that would allow us to get >> rid of the separation eventually. > > I think this is where we disagree. I didn't mean that all controllers > should be using exactly the same hierarchy when I was talking about > unified hierarchy. I do think it's useful and maybe even essential to > allow differing levels of granularity. cpu and cpuacct could be a > valid example for this. Likely blkcg and memcg too. > > So, I think it's desirable for all controllers to be able to handle > hierarchies the same way and to have the ability to tag something as > belonging to certain group in the hierarchy for all controllers but I > don't think it's desirable or feasible to require all of them to > follow exactly the same grouping at all levels. > By "different levels of granularity" do you mean having just a subset of them turned on at a particular place? If yes, having them guaranteed to be comounted is still perceived by me as a good first step. A natural following would be to turn them on/off on a per-group basis.