From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932351AbWJVKwJ (ORCPT ); Sun, 22 Oct 2006 06:52:09 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932352AbWJVKwJ (ORCPT ); Sun, 22 Oct 2006 06:52:09 -0400 Received: from omx2-ext.sgi.com ([192.48.171.19]:2714 "EHLO omx2.sgi.com") by vger.kernel.org with ESMTP id S932351AbWJVKwH (ORCPT ); Sun, 22 Oct 2006 06:52:07 -0400 Date: Sun, 22 Oct 2006 03:51:35 -0700 From: Paul Jackson To: Martin Bligh Cc: nickpiggin@yahoo.com.au, akpm@osdl.org, menage@google.com, Simon.Derr@bull.net, linux-kernel@vger.kernel.org, dino@in.ibm.com, rohitseth@google.com, holt@sgi.com, dipankar@in.ibm.com, suresh.b.siddha@intel.com Subject: Re: [RFC] cpuset: remove sched domain hooks from cpusets Message-Id: <20061022035135.2c450147.pj@sgi.com> In-Reply-To: <4537D6E8.8020501@google.com> References: <20061019092358.17547.51425.sendpatchset@sam.engr.sgi.com> <4537527B.5050401@yahoo.com.au> <20061019120358.6d302ae9.pj@sgi.com> <4537D056.9080108@yahoo.com.au> <4537D6E8.8020501@google.com> 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 Martin wrote: > We (Google) are planning to use it to do some partitioning, albeit on > much smaller machines. I'd really like to NOT use cpus_allowed from > previous experience - if we can get it to to partition using separated > sched domains, that would be much better. Why not use cpus_allowed for this, via cpusets and/or sched_setaffinity? In the followup to this between Paul M. and myself, I wrote: > As best as I can tell, the two motivations for explicity setting > sched domain partitions are: > 1) isolating cpus for real time uses very sensitive to any interference, > 2) handling load balancing on huge CPU counts, where the worse than linear > algorithms start to hurt. > ... > How many CPUs are you juggling? And Paul M. replied: > Not many by your standards - less than eight in general. So ... it would seem you have neither huge CPU counts nor real time sensitivities. So why not use cpus_allowed? -- I won't rest till it's the best ... Programmer, Linux Scalability Paul Jackson 1.925.600.0401