From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932118AbWFRHt2 (ORCPT ); Sun, 18 Jun 2006 03:49:28 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932135AbWFRHt1 (ORCPT ); Sun, 18 Jun 2006 03:49:27 -0400 Received: from smtp107.mail.mud.yahoo.com ([209.191.85.217]:50367 "HELO smtp107.mail.mud.yahoo.com") by vger.kernel.org with SMTP id S932118AbWFRHt0 (ORCPT ); Sun, 18 Jun 2006 03:49:26 -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=go7X00r7xWzlKKvIKon0MN5aRMiMwxe+TowsUiLfdE/erKApVMCWuAvEb3hSdnMqQxLgPTuqJbiUhWuyS9pLgOOwPg1l/+hU1hKgaTqL0puIDkQAADy5vvJ3siMDbTtlACfdQkXZ94JEw0PUvAW/FdvKRfDo3m6fwPfYizH6Mu0= ; Message-ID: <44950580.5080003@yahoo.com.au> Date: Sun, 18 Jun 2006 17:49:20 +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: Mike Galbraith CC: Andrew Morton , sam@vilain.net, vatsa@in.ibm.com, dev@openvz.org, mingo@elte.hu, pwil3058@bigpond.net.au, sekharan@us.ibm.com, balbir@in.ibm.com, 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> <4494DF50.2070509@yahoo.com.au> <4494EA66.8030305@vilain.net> <4494EE86.7090209@yahoo.com.au> <20060617234259.dc34a20c.akpm@osdl.org> <1150616176.7985.50.camel@Homer.TheSimpsons.net> In-Reply-To: <1150616176.7985.50.camel@Homer.TheSimpsons.net> 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 Mike Galbraith wrote: > On Sat, 2006-06-17 at 23:42 -0700, Andrew Morton wrote: > >>On Sun, 18 Jun 2006 16:11:18 +1000 >>Nick Piggin wrote: > > >>>Again, I don't care about the solutions at this stage. I want to know >>>what the problem is. Please? >> >>Isolation. To prevent one group of processes from damaging the performance >>of other groups, by providing manageability of the resource consumption of >>each group. There are plenty of applications of this, not just >>server-consolidation-via-server-virtualisation. > > > Scheduling contexts do sound useful. They're easily defeated though, as > evolution mail demonstrates to me every time it's GUI hangs and I see > that a nice 19 find is running, eating very little CPU, but effectively > DoSing evolution nonetheless (journal). I wonder how often people who > tried to distribute CPU would likewise be stymied by other resources. Not entirely infrequently. Which is why it really doesn't seem like it could be useful from a security point of view without a *huge* amount of work and complexity... and even from a guaranteed-service point of view, it still seems (to me) like a pretty big and complex problem. As a check box for marketing it sounds pretty cool though, I admit ;) -- SUSE Labs, Novell Inc. Send instant messages to your online friends http://au.messenger.yahoo.com