Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755751Ab0GAMdf (ORCPT ); Thu, 1 Jul 2010 08:33:35 -0400 Received: from casper.infradead.org ([85.118.1.10]:37571 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755467Ab0GAMde convert rfc822-to-8bit (ORCPT ); Thu, 1 Jul 2010 08:33:34 -0400 Subject: Re: [PATCH repost] sched: export sched_set/getaffinity to modules From: Peter Zijlstra To: "Michael S. Tsirkin" Cc: Ingo Molnar , Sridhar Samudrala , Tejun Heo , Oleg Nesterov , netdev , lkml , "kvm@vger.kernel.org" , Andrew Morton , Dmitri Vorobiev , Jiri Kosina , Thomas Gleixner , Andi Kleen In-Reply-To: <20100701115507.GA31333@redhat.com> References: <20100528150830.GB21880@redhat.com> <4BFFE742.2060205@kernel.org> <20100530112925.GB27611@redhat.com> <4C02C99D.9070204@kernel.org> <20100624081135.GA937@redhat.com> <1277419551.27868.27.camel@w-sridhar.beaverton.ibm.com> <20100625101022.GA16321@redhat.com> <20100701110708.GA27368@redhat.com> <1277983179.1917.10.camel@laptop> <1277984603.1917.15.camel@laptop> <20100701115507.GA31333@redhat.com> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8BIT Date: Thu, 01 Jul 2010 14:32:43 +0200 Message-ID: <1277987563.1917.28.camel@laptop> Mime-Version: 1.0 X-Mailer: Evolution 2.28.3 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1034 Lines: 24 On Thu, 2010-07-01 at 14:55 +0300, Michael S. Tsirkin wrote: > > - why can't it set the kernel thread's affinity too? > > It can. However: the threads are started internally by the driver > when qemu does an ioctl. What we want to do is give it a sensible > default affinity. management tool can later tweak it if it wants to. So have that ioctl return the tid of that new fancy thread and then set its affinity, stuff it in cgroup, whatever you fancy. > > - what happens if someone changes the tasks' affinity? > > We would normally create a cgroup including all internal > tasks, making it easy to find and change affinity for > them all if necessary. And to stuff them in a cgroup you also need the tid, at which point it might as well set the affinity from userspace, right? -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/