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=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 E8FA3CA9EBC for ; Thu, 24 Oct 2019 16:45:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id BF9B620659 for ; Thu, 24 Oct 2019 16:45:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2393992AbfJXQpe (ORCPT ); Thu, 24 Oct 2019 12:45:34 -0400 Received: from foss.arm.com ([217.140.110.172]:56604 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2390181AbfJXQpd (ORCPT ); Thu, 24 Oct 2019 12:45:33 -0400 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 1589F328; Thu, 24 Oct 2019 09:45:18 -0700 (PDT) Received: from [10.1.194.37] (unknown [10.1.194.37]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 637533F71F; Thu, 24 Oct 2019 09:45:16 -0700 (PDT) Subject: Re: [PATCH v4 1/2] sched/topology: Don't try to build empty sched domains To: Dietmar Eggemann , 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, morten.rasmussen@arm.com, qperret@google.com, stable@vger.kernel.org References: <20191023153745.19515-1-valentin.schneider@arm.com> <20191023153745.19515-2-valentin.schneider@arm.com> <27d8a51d-a899-67f4-8b74-224281f25cef@arm.com> From: Valentin Schneider Message-ID: <7e20f309-3ca0-b916-b703-052ab8284012@arm.com> Date: Thu, 24 Oct 2019 17:45:14 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.8.0 MIME-Version: 1.0 In-Reply-To: <27d8a51d-a899-67f4-8b74-224281f25cef@arm.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 24/10/2019 17:19, Dietmar Eggemann wrote: > Sorry for being picky but IMHO you should also mention that it fixes > > f9a25f776d78 ("cpusets: Rebuild root domain deadline accounting > information") > I can append the following to the changelog, although I'd like some feedback from the cgroup folks before doing a respin: """ Note that commit f9a25f776d78 ("cpusets: Rebuild root domain deadline accounting information") introduced a similar issue. Since doms_new is assigned to doms_cur without any filtering, we can end up with an empty cpumask in the doms_cur array. The next time we go through a rebuild, this will break on: rd = cpu_rq(cpumask_any(doms_cur[i]))->rd; If there wasn't enough already, this is yet another argument for *not* handing over empty cpumasks to the sched domain rebuild. """ I tagged the commit that introduces the static key with Fixes: because it was introduced earlier - I don't think it would make sense to have two "Fixes:" lines? In any case, it'll now be listed in the changelog.