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=-13.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,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 59E35C433E0 for ; Tue, 12 Jan 2021 17:58:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0DF222311D for ; Tue, 12 Jan 2021 17:58:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2391997AbhALR6O (ORCPT ); Tue, 12 Jan 2021 12:58:14 -0500 Received: from foss.arm.com ([217.140.110.172]:50534 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727622AbhALR6N (ORCPT ); Tue, 12 Jan 2021 12:58:13 -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 B0CBD1063; Tue, 12 Jan 2021 09:57:27 -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 0B9623F66E; Tue, 12 Jan 2021 09:57:25 -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 3/4] workqueue: Tag bound workers with KTHREAD_IS_PER_CPU In-Reply-To: <20210112144843.849135905@infradead.org> References: <20210112144344.850850975@infradead.org> <20210112144843.849135905@infradead.org> User-Agent: Notmuch/0.21 (http://notmuchmail.org) Emacs/26.3 (x86_64-pc-linux-gnu) Date: Tue, 12 Jan 2021 17:57:23 +0000 Message-ID: MIME-Version: 1.0 Content-Type: text/plain Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 12/01/21 15:43, Peter Zijlstra wrote: > @@ -4919,8 +4922,10 @@ static void unbind_workers(int cpu) > > raw_spin_unlock_irq(&pool->lock); > > - for_each_pool_worker(worker, pool) > + for_each_pool_worker(worker, pool) { > + kthread_set_per_cpu(worker->task, false); > WARN_ON_ONCE(set_cpus_allowed_ptr(worker->task, cpu_possible_mask) < 0); > + } Doesn't this supersede patch 1? With patch 4 on top, the BALANCE_PUSH stuff should start resetting the affinity of the kworkers for which we are removing the IS_PER_CPU flag. It's the only nit I have, the rest looks good to me so: Reviewed-by: Valentin Schneider I'll go frob that sched_cpu_dying() warning.