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=-5.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS 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 4DD49C4361B for ; Fri, 11 Dec 2020 12:52:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0AD4A23D50 for ; Fri, 11 Dec 2020 12:52:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2405976AbgLKMwa (ORCPT ); Fri, 11 Dec 2020 07:52:30 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57766 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2406012AbgLKMwA (ORCPT ); Fri, 11 Dec 2020 07:52:00 -0500 Received: from merlin.infradead.org (merlin.infradead.org [IPv6:2001:8b0:10b:1231::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 29F43C0613CF for ; Fri, 11 Dec 2020 04:51:20 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=merlin.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=AtrqjaBhwhhm+g6TOXOtlBu/O/X4VKdXfAX1UBzn9+4=; b=r42Qrr0gdwEaZUG11FH7PyquBw 181t6QHqYSsF8uQiCJZsKPT6iyz/91GMYs/dHf3SBp3+udnqMU9qa3G5C4cWepM0eCRP9R+Xn8XoH kYHOtodat/J8eItF/ol2AKc2LvRRTMrQ9WGdLyKeaSXBbkHLLasCQcCplOJCRMA/nkeYkTw2+eNOe J4DsXNHXlvSrhiPBW6IDpKRblJcEzlnwl5fkzfWJ3WsfXEGycbwsKRMSHvE3HN7F5NctKocnQfNok Xq8LLry+v4yLD/2OWAXx+89vtAJoyZnskstw9vZXUOGG4sAsMr3F03fwT8oZe7ay3fWfuq5EwQqXP Zpw4GDDg==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=noisy.programming.kicks-ass.net) by merlin.infradead.org with esmtpsa (Exim 4.92.3 #3 (Red Hat Linux)) id 1knht1-0002a4-FW; Fri, 11 Dec 2020 12:51:03 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id DB4923007CD; Fri, 11 Dec 2020 13:51:01 +0100 (CET) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 9F92C200EC4EA; Fri, 11 Dec 2020 13:51:01 +0100 (CET) Date: Fri, 11 Dec 2020 13:51:01 +0100 From: Peter Zijlstra To: Vincent Donnefort Cc: Valentin Schneider , linux-kernel@vger.kernel.org, Qian Cai , tglx@linutronix.de, mingo@kernel.org, bigeasy@linutronix.de, qais.yousef@arm.com, swood@redhat.com, juri.lelli@redhat.com, vincent.guittot@linaro.org, dietmar.eggemann@arm.com, rostedt@goodmis.org, bsegall@google.com, mgorman@suse.de, bristot@redhat.com, tj@kernel.org, ouwen210@hotmail.com Subject: Re: [PATCH 2/2] workqueue: Fix affinity of kworkers attached during late hotplug Message-ID: <20201211125101.GX2414@hirez.programming.kicks-ass.net> References: <20201210163830.21514-1-valentin.schneider@arm.com> <20201210163830.21514-3-valentin.schneider@arm.com> <20201211113920.GA75974@e120877-lin.cambridge.arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20201211113920.GA75974@e120877-lin.cambridge.arm.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Dec 11, 2020 at 11:39:21AM +0000, Vincent Donnefort wrote: > On Thu, Dec 10, 2020 at 04:38:30PM +0000, Valentin Schneider wrote: > > + if (pool->flags & POOL_DISASSOCIATED) { > > worker->flags |= WORKER_UNBOUND; > > + set_cpus_allowed_ptr(worker->task, cpu_active_mask); > > + } else { > > + /* > > + * set_cpus_allowed_ptr() will fail if the cpumask doesn't have any > > + * online CPUs. It'll be re-applied when any of the CPUs come up. > > + */ > > Does this comment still stand ? IIUC, we should always be in the > POOL_DISASSOCIATED case if the CPU from cpumask is offline. Unless a > pool->attrs->cpumask can have several CPUs. In that case maybe we should check > for the cpu_active_mask here too ? IIUC it can be a numa mask, and would still be valid in that case. > > + set_cpus_allowed_ptr(worker->task, pool->attrs->cpumask); > > + }