From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758489AbXJCMRj (ORCPT ); Wed, 3 Oct 2007 08:17:39 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755794AbXJCMRc (ORCPT ); Wed, 3 Oct 2007 08:17:32 -0400 Received: from netops-testserver-3-out.sgi.com ([192.48.171.28]:51138 "EHLO relay.sgi.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1755499AbXJCMRb (ORCPT ); Wed, 3 Oct 2007 08:17:31 -0400 Date: Wed, 3 Oct 2007 05:17:29 -0700 From: Paul Jackson To: Nick Piggin Cc: akpm@linux-foundation.org, menage@google.com, linux-kernel@vger.kernel.org, dino@in.ibm.com, cpw@sgi.com, mingo@elte.hu Subject: Re: [PATCH] cpuset and sched domains: sched_load_balance flag Message-Id: <20071003051729.df3d8ab9.pj@sgi.com> In-Reply-To: <200710030356.18090.nickpiggin@yahoo.com.au> References: <20070930104403.24828.48263.sendpatchset@jackhammer.engr.sgi.com> <200710030209.56879.nickpiggin@yahoo.com.au> <20071003025518.7c184905.pj@sgi.com> <200710030356.18090.nickpiggin@yahoo.com.au> Organization: SGI X-Mailer: Sylpheed version 2.2.4 (GTK+ 2.8.3; i686-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Nick wrote: > OK, so I don't exactly understand you either. To make it simple, can > you give a concrete example of a cpuset hierarchy that wouldn't > work? It's more a matter of knowing how my third party batch scheduler coders think. They will be off in some corner of their code with a cpuset in hand that they know is just being used to hold inactive (paused) tasks, and they can likely be persuaded to mark those cpusets as not being in need of any wasted CPU cycles load balancing them. But these inactive cpusets will overlap in unknown (to them at the time, in that piece of code) ways with other cpusets holding active jobs, and there is no chance, unless it is a matter of major performance impact, that they will be in any position to comment on the proper partitioning of the sched domains on all the CPUs under the control of their batch scheduler, much less comment on the partitioning of the rest of the system. -- I won't rest till it's the best ... Programmer, Linux Scalability Paul Jackson 1.925.600.0401