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 F075DC433B4 for ; Thu, 15 Apr 2021 15:31:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C1BB761184 for ; Thu, 15 Apr 2021 15:31:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233685AbhDOPbq (ORCPT ); Thu, 15 Apr 2021 11:31:46 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52250 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231137AbhDOPbp (ORCPT ); Thu, 15 Apr 2021 11:31:45 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 941A2C061574 for ; Thu, 15 Apr 2021 08:31:22 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.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=uxFNx8Ls1EjAX5avuFuqLLc2lUBNPz30HeVoOn1uPWc=; b=ffatmZJhGimSLIXmb3ZAtXSywv eCgq7k6Azr3gDPUc5delTOvcRcZqsDOdai7Ynzwmoya8Es/c40PbkRVyJx6I/k5Y1qQyY2UQYYQCg CjkWO7fnhDsl0p54tIlLPel9aAitY4lv/wzNtjhqzip4xRcQhCq+kZ7ZgJf7XQ6xjB338UmTzhdNl ZA0yRlLcsdhzof4tMnszeql8DD3CPNDOsojg2UoHLM9Xa/vO3vnm0eZXXhJI4mak3p2xE6ijlvAjk +3kxT36sgH+oTMx/U87y4uJ1oFm9vfJASiCMYsjshTYN9MtbiFFAW+JN04IxrbX+dV4P7CsL24DT7 YAt0e0Iw==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=noisy.programming.kicks-ass.net) by casper.infradead.org with esmtpsa (Exim 4.94 #2 (Red Hat Linux)) id 1lX3wO-008kng-U2; Thu, 15 Apr 2021 15:30:17 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id 839E6300209; Thu, 15 Apr 2021 17:29:59 +0200 (CEST) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 6C6322C7727AE; Thu, 15 Apr 2021 17:29:59 +0200 (CEST) Date: Thu, 15 Apr 2021 17:29:59 +0200 From: Peter Zijlstra To: Valentin Schneider Cc: tglx@linutronix.de, mingo@kernel.org, bigeasy@linutronix.de, 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, vincent.donnefort@arm.com, qais.yousef@arm.com, linux-kernel@vger.kernel.org Subject: Re: [PATCH 3/3] sched: Use cpu_dying() to fix balance_push vs hotplug-rollback Message-ID: References: <20210310145258.899619710@infradead.org> <20210310150109.259726371@infradead.org> <871rclu3jz.mognet@e113632-lin.i-did-not-set--mail-host-address--so-tickle-me> <87r1jfmn8d.mognet@arm.com> <87a6pzmxec.mognet@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <87a6pzmxec.mognet@arm.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Apr 15, 2021 at 03:32:11PM +0100, Valentin Schneider wrote: > > So instead, make sure balance_push is enabled between > > sched_cpu_deactivate() and sched_cpu_activate() (eg. when > > !cpu_active()), and gate it's utility with cpu_dying(). > > I'd word that "is enabled below sched_cpu_activate()", since > sched_cpu_deactivate() is now out of the picture. I are confused (again!). Did you mean to say something like: 'is enabled below SCHED_AP_ACTIVE' ?