From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758191AbXJCMZO (ORCPT ); Wed, 3 Oct 2007 08:25:14 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754362AbXJCMZC (ORCPT ); Wed, 3 Oct 2007 08:25:02 -0400 Received: from smtp101.mail.mud.yahoo.com ([209.191.85.211]:44036 "HELO smtp101.mail.mud.yahoo.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1754229AbXJCMZB (ORCPT ); Wed, 3 Oct 2007 08:25:01 -0400 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=s1024; d=yahoo.com.au; h=Received:X-YMail-OSG:From:To:Subject:Date:User-Agent:Cc:References:In-Reply-To:MIME-Version:Content-Type:Content-Transfer-Encoding:Content-Disposition:Message-Id; b=fmxAU+jAMm846eQJSJNoXNC8aMvv5Tjo8zmdGMes0BpeNjSSrzXkfE+I/cAOoP+P/abRt3uaYbhfeRzkuYkJNe/N90LPY4BMesSt+5O2xBhmFsDpztM1fvV2RnDOsiCSQGK9FtjQAFd4phK0ZzoyQZlSYMd2zFlprTnlsWmwRSA= ; X-YMail-OSG: h6D889oVM1kYX_V96WwLzhYZga0Tq4BXtaLO3sgMBDcNkOnb8xxrW51gztlQAdHZoTRVr1eqrQ-- From: Nick Piggin To: Paul Jackson Subject: Re: [PATCH] cpuset and sched domains: sched_load_balance flag Date: Wed, 3 Oct 2007 05:53:27 +1000 User-Agent: KMail/1.9.5 Cc: akpm@linux-foundation.org, menage@google.com, linux-kernel@vger.kernel.org, dino@in.ibm.com, cpw@sgi.com, mingo@elte.hu References: <20070930104403.24828.48263.sendpatchset@jackhammer.engr.sgi.com> <200710030525.29735.nickpiggin@yahoo.com.au> <20071003051438.e1371e99.pj@sgi.com> In-Reply-To: <20071003051438.e1371e99.pj@sgi.com> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200710030553.27822.nickpiggin@yahoo.com.au> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Wednesday 03 October 2007 22:14, Paul Jackson wrote: > > These are what I'm worried about, and things like kswapd, pdflush, > > could definitely use a huge amount of CPU. > > > > If you are interested in hard partitioning the system, you most > > definitely want these things to be balanced across the non-isolated > > CPUs. > > But these guys are pinned anyway (or else they would already be moved > into a smaller load balanced cpuset), so why waste time load balancing > what can't move? They're not pinned (kswapds are pinned to a node, but still). pdflush is not pinned at all and can be dynamically created and destroyed. Ditto for kjournald, as well as many others. Basically: it doesn't feel like a satisfactory solution to brush these under the carpet. > And on some of the systems I care about, we don't want to load balance > these guys; rather we go to great lengths to see that they don't run at > all when we don't want them to. Most smaller realtime partitioned systems will want to, I'd expect.