Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965338AbbGVOLw (ORCPT ); Wed, 22 Jul 2015 10:11:52 -0400 Received: from mail-yk0-f177.google.com ([209.85.160.177]:35993 "EHLO mail-yk0-f177.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933561AbbGVOLv (ORCPT ); Wed, 22 Jul 2015 10:11:51 -0400 Date: Wed, 22 Jul 2015 10:11:48 -0400 From: Tejun Heo To: Mike Galbraith Cc: Lai Jiangshan , Frederic Weisbecker , Daniel Bristot de Oliveira , LKML , Rik van Riel , "Luis Claudio R. Goncalves" Subject: Re: [patch] workqueue: schedule WORK_CPU_UNBOUND work on wq_unbound_cpumask CPUs Message-ID: <20150722141148.GL15934@mtj.duckdns.org> References: <9e53de7c91c885ee255e16ee25f401d9eedf08d9.1437067317.git.bristot@redhat.com> <20150716192448.GY15934@mtj.duckdns.org> <1437107190.3438.23.camel@gmail.com> <20150717152720.GD15934@mtj.duckdns.org> <1437153348.5860.32.camel@gmail.com> <20150718133602.GA3041@lerouge> <1437292973.3505.83.camel@gmail.com> <1437468925.12755.57.camel@gmail.com> <1437542686.3106.55.camel@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1437542686.3106.55.camel@gmail.com> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1007 Lines: 23 On Wed, Jul 22, 2015 at 07:24:46AM +0200, Mike Galbraith wrote: > WORK_CPU_UNBOUND work items queued to a bound workqueue always run > locally. This is a good thing normally, but not when the user has The constant name used there is a bit misleading but you can't put work items which are queued w/ queue_work() on foreign cpus by default. queue_work() has always guaranteed local execution. The problem is that workqueue can't currently tell whether a queue_work() user expects cpu locality for correctness or optimization. It'd be great if we introduce queue_work_on_local() or sth and replace correctness ones with it but that involves auditing each and every queue_work() usage. If anybody is up for the task, I'd be happy to help. Thanks. -- tejun -- 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/