From mboxrd@z Thu Jan 1 00:00:00 1970 From: Glauber Costa Subject: Re: [RFC 0/5] forced comounts for cgroups. Date: Wed, 5 Sep 2012 12:55:21 +0400 Message-ID: <50471379.3060603@parallels.com> 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> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20120905084740.GE3195-RcKxWJ4Cfj1J2suj2OqeGauc2jM2gXBXkQQo+JxHRPFibQn6LdNjmg@public.gmane.org> Sender: cgroups-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-ID: Content-Type: text/plain; charset="us-ascii" To: Tejun Heo Cc: linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-mm-Bw31MaZKKs3YtjvyW6yDsg@public.gmane.org, davej-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, ben-/+tVBieCtBitmTQ+vhA3Yw@public.gmane.org, a.p.zijlstra-/NLkJaSkS4VmR6Xm/wNWPw@public.gmane.org, pjt-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org, lennart-mdGvqq1h2p+GdvJs77BJ7Q@public.gmane.org, kay.sievers-tD+1rO4QERM@public.gmane.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.