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=-8.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS 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 1AF7EC433E6 for ; Thu, 21 Jan 2021 14:02:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DD011239D4 for ; Thu, 21 Jan 2021 14:02:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730857AbhAUOCQ (ORCPT ); Thu, 21 Jan 2021 09:02:16 -0500 Received: from foss.arm.com ([217.140.110.172]:37366 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726375AbhAUOBj (ORCPT ); Thu, 21 Jan 2021 09:01:39 -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 8A3CD11D4; Thu, 21 Jan 2021 06:00:53 -0800 (PST) Received: from e113632-lin (e113632-lin.cambridge.arm.com [10.1.194.46]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id DD3E63F68F; Thu, 21 Jan 2021 06:00:51 -0800 (PST) From: Valentin Schneider To: Peter Zijlstra , mingo@kernel.org, tglx@linutronix.de Cc: linux-kernel@vger.kernel.org, jiangshanlai@gmail.com, cai@redhat.com, vincent.donnefort@arm.com, decui@microsoft.com, paulmck@kernel.org, vincent.guittot@linaro.org, rostedt@goodmis.org, tj@kernel.org, peterz@infradead.org Subject: Re: [PATCH -v3 3/9] sched: Dont run cpu-online with balance_push() enabled In-Reply-To: <20210121103506.415606087@infradead.org> References: <20210121101702.402798862@infradead.org> <20210121103506.415606087@infradead.org> User-Agent: Notmuch/0.21 (http://notmuchmail.org) Emacs/26.3 (x86_64-pc-linux-gnu) Date: Thu, 21 Jan 2021 14:00:45 +0000 Message-ID: MIME-Version: 1.0 Content-Type: text/plain Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 21/01/21 11:17, Peter Zijlstra wrote: > @@ -7608,6 +7614,12 @@ int sched_cpu_dying(unsigned int cpu) > } > rq_unlock_irqrestore(rq, &rf); > > + /* > + * Should really be after we clear cpu_online(), but we're in > + * stop_machine(), so it all works. > + */ I believe you noted yourself in some earlier version that this *is* running with cpu_online(cpu) == false, __cpu_disable() being invoked before the _DYING .teardown callbacks are run. > + balance_push_set(cpu, false); > + > calc_load_migrate(rq); > update_max_interval(); > nohz_balance_exit_idle(rq);