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=-10.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,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 A8CE9C433E0 for ; Thu, 21 Jan 2021 14:17:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 55FF7239D1 for ; Thu, 21 Jan 2021 14:17:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728466AbhAUORC (ORCPT ); Thu, 21 Jan 2021 09:17:02 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49498 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726320AbhAUOPw (ORCPT ); Thu, 21 Jan 2021 09:15:52 -0500 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BD6A2C061575 for ; Thu, 21 Jan 2021 06:15:11 -0800 (PST) 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=kkZoVMI8wUStGleFdEU/MPC3jyb8xZnP+NsWwxV31bQ=; b=on1Mp5P7+YomwsO9dYXvJde88E txFMu0q6bX+bQHXAhy44PZcKNo0DM4KHtooPCFPu0McTAmMYywsxov8lMphU1ZITq+InqOcOnsqkq P0LRTrpqf601qzAzfmbQNChUSkxXWtRno9ZiHWYw+mKX+yygV2YvLYImigjMMwzvN8jhC8X16KLew cp9ItVvaUJT5cEZTstDu4m7z3unrZtOMmpIBOM86gOzNRScOw4Ro9iAN673/cAAqzYqTPxC2eUf+y Wd65mlxBm/DF9e/ltPvcEzsiv+gVEa+c06vATjoRCWSuN6tu2l6N4N9wW/aEK8xQvTbWNz5JNokpZ l6q4CD5g==; 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 1l2aiq-00H8WT-HQ; Thu, 21 Jan 2021 14:14:15 +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 E9F893003E1; Thu, 21 Jan 2021 15:14:02 +0100 (CET) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id B04542028D525; Thu, 21 Jan 2021 15:14:02 +0100 (CET) Date: Thu, 21 Jan 2021 15:14:02 +0100 From: Peter Zijlstra To: Valentin Schneider Cc: mingo@kernel.org, tglx@linutronix.de, 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 Subject: Re: [PATCH -v3 3/9] sched: Dont run cpu-online with balance_push() enabled Message-ID: References: <20210121101702.402798862@infradead.org> <20210121103506.415606087@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jan 21, 2021 at 02:00:45PM +0000, Valentin Schneider wrote: > 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. Argh! lemme go fix that comment.