From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753742AbXDLVB6 (ORCPT ); Thu, 12 Apr 2007 17:01:58 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753743AbXDLVB6 (ORCPT ); Thu, 12 Apr 2007 17:01:58 -0400 Received: from ausmtp04.au.ibm.com ([202.81.18.152]:61014 "EHLO ausmtp04.au.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753741AbXDLVB4 (ORCPT ); Thu, 12 Apr 2007 17:01:56 -0400 Message-ID: <461E9DEF.3090707@in.ibm.com> Date: Fri, 13 Apr 2007 02:30:31 +0530 From: Balbir Singh Reply-To: balbir@in.ibm.com Organization: IBM User-Agent: Thunderbird 1.5.0.10 (X11/20070306) MIME-Version: 1.0 To: Andrew Morton CC: Pavel Emelianov , Paul Menage , Linux Kernel Mailing List , devel@openvz.org, Kirill Korotaev , Srivatsa Vaddagiri Subject: Re: [PATCH] Cpu statistics accounting based on Paul Menage patches References: <461CF883.2030308@sw.ru> <20070411114927.1277d7c9.akpm@linux-foundation.org> In-Reply-To: <20070411114927.1277d7c9.akpm@linux-foundation.org> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Andrew Morton wrote: > On Wed, 11 Apr 2007 19:02:27 +0400 > Pavel Emelianov wrote: > >> Provides a per-container statistics concerning the numbers of tasks >> in various states, system and user times, etc. Patch is inspired >> by Paul's example of the used CPU time accounting. Although this >> patch is independent from Paul's example to make it possible playing >> with them separately. > > Why is this actually needed? If userspace has a list of the tasks which > are in a particular container, it can run around and add up the stats for > those tasks without kernel changes? > > It's a bit irksome that we have so much accounting of this form in core > kernel, yet we have to go and add a completely new implementation to create > something which is similar to what we already have. But I don't > immediately see a fix for that. Apart from paragraph #1 ;) > > Should there be linkage between per-container stats and > delivery-via-taskstats? I can't think of one, really. > > You have cpu stats. Later, presumably, we'll need IO stats, MM stats, > context-switch stats, number-of-syscall stats, etc, etc. Are we going to > reimplement all of those things as well? See paragraph #1! > > Bottom line: I think we seriously need to find some way of consolidating > per-container stats with our present per-task stats. Perhaps we should > instead be looking at ways in which we can speed up paragraph #1. This should be easy to build. per container stats can live in parallel with per-task stats, but they can use the same general mechanism for data communication to user space. -- Warm Regards, Balbir Singh Linux Technology Center IBM, ISTL