From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934887Ab1JETTh (ORCPT ); Wed, 5 Oct 2011 15:19:37 -0400 Received: from casper.infradead.org ([85.118.1.10]:60802 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934402Ab1JETTf convert rfc822-to-8bit (ORCPT ); Wed, 5 Oct 2011 15:19:35 -0400 Subject: Re: [PATCH 4/8] kernel/workqueue.c: unbound work queue rescuer runs on first cpu in cpumask_online_cpu From: Peter Zijlstra To: Thomas Gleixner Cc: Fenghua Yu , Ingo Molnar , H Peter Anvin , Zwane Mwaikambo , Tony Luck , Asit K Mallick , Suresh B Siddha , Len Brown , linux-kernel , Tejun Heo Date: Wed, 05 Oct 2011 21:19:22 +0200 In-Reply-To: References: <1317832759-10223-1-git-send-email-fenghua.yu@intel.com> <1317832759-10223-5-git-send-email-fenghua.yu@intel.com> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8BIT X-Mailer: Evolution 3.0.3- Message-ID: <1317842362.6766.42.camel@twins> Mime-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 2011-10-05 at 20:52 +0200, Thomas Gleixner wrote: > On Wed, 5 Oct 2011, Fenghua Yu wrote: > > > From: Fenghua Yu > > > > If work queue is unbound to a specific cpu, run rescuer on first cpu in > > cpumask_online_cpu instead BSP which could be offlined. > > This patch needs to be applied separate from that series as it fixes a > bug which affects all architectures which can offline the boot cpu. AFAIKT it really doesn't matter in this case, all the rescuer_thread() needs is some bit set in that mask, since its UNBOUND it won't actually try and migrate to any cpu and just run wherever it woke up.