From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1765106AbYEBJOc (ORCPT ); Fri, 2 May 2008 05:14:32 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752432AbYEBJOY (ORCPT ); Fri, 2 May 2008 05:14:24 -0400 Received: from e28smtp03.in.ibm.com ([59.145.155.3]:57683 "EHLO e28smtp03.in.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752394AbYEBJOX (ORCPT ); Fri, 2 May 2008 05:14:23 -0400 Message-ID: <481ADB66.1010007@linux.vnet.ibm.com> Date: Fri, 02 May 2008 14:44:14 +0530 From: Balbir Singh Reply-To: balbir@linux.vnet.ibm.com Organization: IBM User-Agent: Thunderbird 2.0.0.12 (X11/20080226) MIME-Version: 1.0 To: Paul Menage CC: Dhaval Giani , vivk@us.ibm.com, Peter Zijlstra , Balbir Singh , Srivatsa Vaddagiri , lkml , libcg-devel , Balaji Rao Subject: Re: [Libcg-devel] cgroupstats, plans? References: <20080429122019.GE9585@linux.vnet.ibm.com> <6599ad830805011852t7dc6de32qd4c105a51c2fee06@mail.gmail.com> In-Reply-To: <6599ad830805011852t7dc6de32qd4c105a51c2fee06@mail.gmail.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 Paul Menage wrote: > On Tue, Apr 29, 2008 at 5:20 AM, Dhaval Giani wrote: >> Hi Paul, >> >> You had mentioned in http://lkml.org/lkml/2008/4/8/29 about cgroup >> binary API for statistics. What is the status wrt to that? > > I've not really had mmore time to work on that since then. > > Assuming people are happy with the basic ideas in that post then I > guess the important questions to focus on would be: > > - what form should the API description to userspace take? Something > like the cgroup.api file that I proposed a while ago? > > - how would the user specify and retrieve a specific set of stats? > should we just dump all stats on each read request, or will that be > too expensive for some stats? > I would prefer to select the controller from user stats and then dump the stats from the kernel for that controller using cgroupstats. >> We are looking to export statistics using libcg. One of the questions >> that comes up is when is a file in the cgroup, a control file (one used >> to control the parameters of the subsystem) and when is it a file which >> is related to statistics. > > I don't see why some of them can't be both. If a file has a numerical > value associated with it, is there any reason not to make it available > via the binary stats API, regardless of whether that value was > generated by userspace or the kernel? > I agree. I think we need to start pushing the statistics so that we can have a good set of statistics. I am going to try and do some cgroupstats work and publish it soon. -- Warm Regards, Balbir Singh Linux Technology Center IBM, ISTL