Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753062AbbDGB6X (ORCPT ); Mon, 6 Apr 2015 21:58:23 -0400 Received: from mail-qc0-f171.google.com ([209.85.216.171]:33876 "EHLO mail-qc0-f171.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752819AbbDGB6U (ORCPT ); Mon, 6 Apr 2015 21:58:20 -0400 Date: Mon, 6 Apr 2015 21:58:17 -0400 From: Tejun Heo To: Lai Jiangshan Cc: linux-kernel@vger.kernel.org, Christoph Lameter , Kevin Hilman , Mike Galbraith , "Paul E. McKenney" , Viresh Kumar , Frederic Weisbecker Subject: Re: [PATCH 4/4 V6] workqueue: Allow modifying low level unbound workqueue cpumask Message-ID: <20150407015817.GJ10582@htj.duckdns.org> References: <1426653617-3240-1-git-send-email-laijs@cn.fujitsu.com> <1427973282-3052-1-git-send-email-laijs@cn.fujitsu.com> <1427973282-3052-5-git-send-email-laijs@cn.fujitsu.com> <20150406155315.GD10582@htj.duckdns.org> <55233227.9090701@cn.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <55233227.9090701@cn.fujitsu.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: 1456 Lines: 38 Hello, Lai. On Tue, Apr 07, 2015 at 09:25:59AM +0800, Lai Jiangshan wrote: > On 04/06/2015 11:53 PM, Tejun Heo wrote: > > On Thu, Apr 02, 2015 at 07:14:42PM +0800, Lai Jiangshan wrote: > >> /* make a copy of @attrs and sanitize it */ > >> copy_workqueue_attrs(new_attrs, attrs); > >> - cpumask_and(new_attrs->cpumask, new_attrs->cpumask, wq_unbound_global_cpumask); > >> + copy_workqueue_attrs(pwq_attrs, attrs); > >> + cpumask_and(new_attrs->cpumask, new_attrs->cpumask, cpu_possible_mask); > >> + cpumask_and(pwq_attrs->cpumask, pwq_attrs->cpumask, unbound_cpumask); > > > > Hmmm... why do we need to keep track of both cpu_possible_mask and > > unbound_cpumask? Can't we just make unbound_cpumask replace > > cpu_possible_mask for unbound workqueues? > > > > I want to save the original user-setting cpumask. > > When any time the wq_unbound_global_cpumask is changed, > the new effective cpumask is > the-original-user-setting-cpumask & wq_unbound_global_cpumask > instead of > the-last-effective-cpumask & wq_unbound_global_cpumask. Yes, I get that, but that'd require just tracking the original configured value and the unbound_cpumask masked value, no? What am I missing? 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/