From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758218AbXJCRqv (ORCPT ); Wed, 3 Oct 2007 13:46:51 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754346AbXJCRqo (ORCPT ); Wed, 3 Oct 2007 13:46:44 -0400 Received: from netops-testserver-3-out.sgi.com ([192.48.171.28]:51420 "EHLO relay.sgi.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1754465AbXJCRqn (ORCPT ); Wed, 3 Oct 2007 13:46:43 -0400 Date: Wed, 3 Oct 2007 10:46:40 -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: <20071003104640.85c8208b.pj@sgi.com> In-Reply-To: <200710030630.19850.nickpiggin@yahoo.com.au> References: <20070930104403.24828.48263.sendpatchset@jackhammer.engr.sgi.com> <200710030553.27822.nickpiggin@yahoo.com.au> <20071003054149.a18b0547.pj@sgi.com> <200710030630.19850.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: > So if a new pdflush is spawned, it get's moved to some cpuset? That > probably isn't something these realtime systems want to do (ie. the > non-realtime portion probably doesn't want to have any sort of scheduler > or even worry about cpusets at all). No - the new pdflush is put in the same cpuset as its parent, with a patch that I sent in early this year. See the following code in mm/pdflush.c: /* * Some configs put our parent kthread in a limited cpuset, * which kthread() overrides, forcing cpus_allowed == CPU_MASK_ALL. * Our needs are more modest - cut back to our cpusets cpus_allowed. * This is needed as pdflush's are dynamically created and destroyed. * The boottime pdflush's are easily placed w/o these 2 lines. */ cpus_allowed = cpuset_cpus_allowed(current); set_cpus_allowed(current, cpus_allowed); return __pdflush(&my_work); -- I won't rest till it's the best ... Programmer, Linux Scalability Paul Jackson 1.925.600.0401