From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id BAAA8C432C3 for ; Thu, 14 Nov 2019 16:03:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 991A5206DB for ; Thu, 14 Nov 2019 16:03:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726865AbfKNQDx (ORCPT ); Thu, 14 Nov 2019 11:03:53 -0500 Received: from foss.arm.com ([217.140.110.172]:45590 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726567AbfKNQDx (ORCPT ); Thu, 14 Nov 2019 11:03:53 -0500 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id E4531328; Thu, 14 Nov 2019 08:03:52 -0800 (PST) Received: from [10.1.194.37] (e113632-lin.cambridge.arm.com [10.1.194.37]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 717EF3F52E; Thu, 14 Nov 2019 08:03:51 -0800 (PST) Subject: Re: [PATCH v2] sched/topology, cpuset: Account for housekeeping CPUs to avoid empty cpumasks From: Valentin Schneider To: linux-kernel@vger.kernel.org, cgroups@vger.kernel.org Cc: lizefan@huawei.com, tj@kernel.org, hannes@cmpxchg.org, mingo@kernel.org, peterz@infradead.org, vincent.guittot@linaro.org, Dietmar.Eggemann@arm.com, morten.rasmussen@arm.com, qperret@google.com, =?UTF-8?Q?Michal_Koutn=c3=bd?= References: <20191104003906.31476-1-valentin.schneider@arm.com> Message-ID: Date: Thu, 14 Nov 2019 16:03:50 +0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.9.0 MIME-Version: 1.0 In-Reply-To: <20191104003906.31476-1-valentin.schneider@arm.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 04/11/2019 00:39, Valentin Schneider wrote: > Michal noted that a cpuset's effective_cpus can be a non-empy mask, but > because of the masking done with housekeeping_cpumask(HK_FLAG_DOMAIN) > further down the line, we can still end up with an empty cpumask being > passed down to partition_sched_domains_locked(). > > Do the proper thing and don't just check the mask is non-empty - check > that its intersection with housekeeping_cpumask(HK_FLAG_DOMAIN) is > non-empty. > > Fixes: cd1cb3350561 ("sched/topology: Don't try to build empty sched domains") > Reported-by: Michal Koutný Michal, could I nag you for a reviewed-by? I'd feel a bit more confident with any sort of approval from folks who actually do use cpusets. > Signed-off-by: Valentin Schneider