From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932092AbWFRFGc (ORCPT ); Sun, 18 Jun 2006 01:06:32 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932095AbWFRFGb (ORCPT ); Sun, 18 Jun 2006 01:06:31 -0400 Received: from smtp103.mail.mud.yahoo.com ([209.191.85.213]:3696 "HELO smtp103.mail.mud.yahoo.com") by vger.kernel.org with SMTP id S932092AbWFRFGb (ORCPT ); Sun, 18 Jun 2006 01:06:31 -0400 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=s1024; d=yahoo.com.au; h=Received:Message-ID:Date:From:User-Agent:X-Accept-Language:MIME-Version:To:CC:Subject:References:In-Reply-To:Content-Type:Content-Transfer-Encoding; b=51eg05bVSVDiyTbEqx+r09/mNdO4AViDGBNRQUQEmZGAo5Ke9FRkQizWoyvIzQRl2RBEMDaqbVFtDKJMZtqJvSRw6sDBg+0BZNFyQMl990gUA0atstc22m+NE/tzFULDhjzNQ45gJX6y+tBVheDm2esINEh8bEb/eXTtGFEEFB0= ; Message-ID: <4494DF50.2070509@yahoo.com.au> Date: Sun, 18 Jun 2006 15:06:24 +1000 From: Nick Piggin User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.7.12) Gecko/20051007 Debian/1.7.12-1 X-Accept-Language: en MIME-Version: 1.0 To: vatsa@in.ibm.com CC: Sam Vilain , Kirill Korotaev , Mike Galbraith , Ingo Molnar , Peter Williams , Andrew Morton , sekharan@us.ibm.com, Balbir Singh , linux-kernel@vger.kernel.org, maeda.naoaki@jp.fujitsu.com, kurosawa@valinux.co.jp Subject: Re: [RFC] CPU controllers? References: <20060615134632.GA22033@in.ibm.com> <4493C1D1.4020801@yahoo.com.au> <20060617164812.GB4643@in.ibm.com> In-Reply-To: <20060617164812.GB4643@in.ibm.com> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Srivatsa Vaddagiri wrote: > On Sat, Jun 17, 2006 at 06:48:17PM +1000, Nick Piggin wrote: > >>Srivatsa Vaddagiri wrote: >> >>> - Do we need mechanisms to control CPU usage of tasks, further to >>> what >>> already exists (like nice)? IMO yes. >> >>Can we get back to the question of need? And from there, work out what >>features are wanted. >> >>IMHO, having containers try to virtualise all resources (memory, pagecache, >>slab cache, CPU, disk/network IO...) seems insane: we may just as well use >>virtualisation. >> >>So, from my POV, I would like to be convinced of the need for this first. >>I would really love to be able to keep core kernel simple and fast even if >>it means edge cases might need to use a slightly different solution. > > > I think a proportional-share scheduler (which is what a CPU controller > may provide) has non-container uses also. Do you think nice (or sched policy) > is enough to, say, provide guaranteed CPU usage for applications or limit > their CPU usage? Moreover it is more flexible if guarantee/limit can be > specified for a group of tasks, rather than individual tasks even in > non-container scenarios (like limiting CPU usage of all web-server > tasks togther or for limiting CPU usage of make -j command). > Oh, I'm sure there are lots of things we *could* do that we currently can't. What I want to establish first is: what exact functionality is required, why, and by whom. Only then can we sanely discuss the fitness of solutions and propose alternatives, and decide whether to merge. -- SUSE Labs, Novell Inc. Send instant messages to your online friends http://au.messenger.yahoo.com