From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965120AbWHWTIr (ORCPT ); Wed, 23 Aug 2006 15:08:47 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S965118AbWHWTIr (ORCPT ); Wed, 23 Aug 2006 15:08:47 -0400 Received: from omx1-ext.sgi.com ([192.48.179.11]:9649 "EHLO omx1.americas.sgi.com") by vger.kernel.org with ESMTP id S965105AbWHWTIq (ORCPT ); Wed, 23 Aug 2006 15:08:46 -0400 Date: Wed, 23 Aug 2006 12:08:38 -0700 From: Paul Jackson To: Anton Blanchard Cc: akpm@osdl.org, simon.derr@bull.net, nathanl@austin.ibm.com, linux-kernel@vger.kernel.org Subject: Re: cpusets not cpu hotplug aware Message-Id: <20060823120838.efbd79c2.pj@sgi.com> In-Reply-To: <20060823145817.GA28175@krispykreme> References: <20060821132709.GB8499@krispykreme> <20060821104334.2faad899.pj@sgi.com> <20060821192133.GC8499@krispykreme> <20060821140148.435d15f3.pj@sgi.com> <20060821215120.244f1f6f.akpm@osdl.org> <20060821220625.36abd1d9.pj@sgi.com> <20060821221433.2bc18198.akpm@osdl.org> <20060823145817.GA28175@krispykreme> 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 Anton wrote: > We have a userspace visible change to the sched > affinity API when the cpusets option is enabled. Yup - on cpuset kernels, sched_setaffinity is constrained to CPUs in a tasks cpuset. Also mbind and set_mempolicy are constrained to nodes in the tasks cpuset. This is a long standing, intentional part of the cpuset design. Using udev isn't papering over it. It's reflecting the reasonable preference and expectation on systems using hotplug/unplug that the default cpuset dynamically reflect the current online maps, not the static maps as they were at boot. And using udev is using just the sort of mechanism one might expect to be used to adjust the system when devices go on or off line. -- I won't rest till it's the best ... Programmer, Linux Scalability Paul Jackson 1.925.600.0401