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=-6.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 9B4C3C4363A for ; Mon, 5 Oct 2020 15:10:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5D1B420774 for ; Mon, 5 Oct 2020 15:10:54 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="fDDcAahm" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727063AbgJEPKp (ORCPT ); Mon, 5 Oct 2020 11:10:45 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45824 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726935AbgJEPKQ (ORCPT ); Mon, 5 Oct 2020 11:10:16 -0400 Received: from merlin.infradead.org (merlin.infradead.org [IPv6:2001:8b0:10b:1231::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id F0C01C0613AA for ; Mon, 5 Oct 2020 08:10:15 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=merlin.20170209; h=Content-Type:MIME-Version:References: Subject:Cc:To:From:Date:Message-ID:Sender:Reply-To:Content-Transfer-Encoding: Content-ID:Content-Description:In-Reply-To; bh=3HlhKZQ3pvdkw49M78oHLmhhJAoeRAhQ/1n3ZZIj6n8=; b=fDDcAahmyOjHuPOt4GfugbFxIs G2JL9MPJKuKPZAtWcZSqQoZXerGFpBtONxblxR11iQ0rLH/1ixAxU/rtSfo90qvQzI1PdIFGKXYN4 erglP8ZgJ7bePo7ajIT71TX1inHwyKLE5ri85kKVilG729sZFx8Z9OIjJMQRGtKw/hT0IvAp2QULm EqmnyiKMBeieWtOV58PZze+zMfBmftWMcjjmkVs1Ojp/Qs74IIxmyewIDowaG6/VToKtfPut6kUNv PDZsAarZu+ejHhIVizx5sE9I9AMAjwjN6Y4kghIXZsU4CoP19GLpqp7akB7In0feq5Qio+7bk8CF2 ogGtrL6w==; 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 1kPS7U-0008OZ-RM; Mon, 05 Oct 2020 15:09:45 +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 5D10D305C22; Mon, 5 Oct 2020 17:09:43 +0200 (CEST) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 0) id CD1B829A897B6; Mon, 5 Oct 2020 17:09:42 +0200 (CEST) Message-ID: <20201005150921.463998937@infradead.org> User-Agent: quilt/0.66 Date: Mon, 05 Oct 2020 16:57:22 +0200 From: Peter Zijlstra To: tglx@linutronix.de, mingo@kernel.org Cc: linux-kernel@vger.kernel.org, bigeasy@linutronix.de, qais.yousef@arm.com, swood@redhat.com, peterz@infradead.org, valentin.schneider@arm.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, vincent.donnefort@arm.com, tj@kernel.org Subject: [PATCH -v2 05/17] workqueue: Manually break affinity on hotplug References: <20201005145717.346020688@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Don't rely on the scheduler to force break affinity for us -- it will stop doing that for per-cpu-kthreads. Signed-off-by: Peter Zijlstra (Intel) --- kernel/workqueue.c | 4 ++++ 1 file changed, 4 insertions(+) --- a/kernel/workqueue.c +++ b/kernel/workqueue.c @@ -4905,6 +4905,10 @@ static void unbind_workers(int cpu) pool->flags |= POOL_DISASSOCIATED; raw_spin_unlock_irq(&pool->lock); + + for_each_pool_worker(worker, pool) + WARN_ON_ONCE(set_cpus_allowed_ptr(worker->task, cpu_active_mask) < 0); + mutex_unlock(&wq_pool_attach_mutex); /*