From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759275Ab3JOPZo (ORCPT ); Tue, 15 Oct 2013 11:25:44 -0400 Received: from mail-qe0-f53.google.com ([209.85.128.53]:63385 "EHLO mail-qe0-f53.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758875Ab3JOPZm (ORCPT ); Tue, 15 Oct 2013 11:25:42 -0400 Date: Tue, 15 Oct 2013 11:25:38 -0400 From: Tejun Heo To: Li Zefan Cc: LKML , cgroups Subject: Re: [PATCH v2 05/12] cpuset: use effective cpumask to build sched domains Message-ID: <20131015152538.GL3141@htj.dyndns.org> References: <5257C9A1.1030404@huawei.com> <5257C9EE.9080902@huawei.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <5257C9EE.9080902@huawei.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Oct 11, 2013 at 05:50:38PM +0800, Li Zefan wrote: > @@ -930,10 +931,21 @@ static void update_cpumasks_hier(struct cpuset *cs, struct cpuset *trialcs, > > update_tasks_cpumask(cp, heap); > > + /* > + * If the effective cpumask of any non-empty cpuset is > + * changed, we need to rebuild sched domains. > + */ > + if (!cpumask_empty(cp->cpus_allowed) && > + is_sched_load_balance(cp)) > + need_rebuild_sched_domains = true; > + Can you please explain *why* this change is being made in the patch description? The patch description doesn't give me anything and the comment explain "what" but not why it's moved from update_cpumask() into this function with an extra condition. Thanks. -- tejun