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 8730EC43381 for ; Sat, 16 Jan 2021 17:14:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 55E0E22573 for ; Sat, 16 Jan 2021 17:14:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728183AbhAPROF (ORCPT ); Sat, 16 Jan 2021 12:14:05 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39078 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728194AbhAPRKW (ORCPT ); Sat, 16 Jan 2021 12:10:22 -0500 Received: from merlin.infradead.org (merlin.infradead.org [IPv6:2001:8b0:10b:1231::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DF5F6C061343 for ; Sat, 16 Jan 2021 07:26:12 -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=lEkmXUGH1YNwygH6nrMd02lMU+09Eibdw952KwXXOg4=; b=ZeIf15YlVFCWTr1mJcvBAYNsl7 hPSuVkaEKAz0N2k8fNsjQXf+huRm5Gmd5W7pWIlzZ06G1zNr8KAPpqqHNUj26UR7r/53nMWfqYk1r thzI9BRsGoW3jJXFOoKtg/QQFe3kuoSv3gmu9BIxzpyz9z/d4Ha1KeCFJdoTc+IBGxhrNz52lmXSh F4CdGyZ3LfQFEdsJyxgtZ67FxQRkzbrrmqbtSnalzkFwU8MTRilSPYIcx8uPv3GNOnyQ/QMyKHImK 9lCjvUDdfS3icHfZ7e/Itbn2zRN+Yab4xGZKPMS4x0YbGw2kdPJ9isUpWKmfMiBGWXySrGTUQ3eME BIjP5TOA==; 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 1l0nSj-0005tv-B6; Sat, 16 Jan 2021 15:26:01 +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 629E23010CF; Sat, 16 Jan 2021 16:25:58 +0100 (CET) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 22F7C202A3F5A; Sat, 16 Jan 2021 16:25:58 +0100 (CET) Date: Sat, 16 Jan 2021 16:25:58 +0100 From: Peter Zijlstra To: mingo@kernel.org, tglx@linutronix.de Cc: linux-kernel@vger.kernel.org, jiangshanlai@gmail.com, valentin.schneider@arm.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 0/8] sched: Fix hot-unplug regressions Message-ID: References: <20210116113033.608340773@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210116113033.608340773@infradead.org> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, Jan 16, 2021 at 12:30:33PM +0100, Peter Zijlstra wrote: > Hi, > > These patches (no longer 4), seems to fix all the hotplug regressions as per > nearly a 100 18*SRCU-P runs over-night. > > I did clean up the patches, so possibly I wrecked it again. I've started new > runs and will again leave them running over-night. Hurph... I've got one splat from this version, one I've not seen before: [ 68.712848] Dying CPU not properly vacated! ... [ 68.744448] CPU1 enqueued tasks (2 total): [ 68.745018] pid: 14, name: rcu_preempt [ 68.745557] pid: 18, name: migration/1 Paul, rcu_preempt, is from rcu_spawn_gp_kthread(), right? Afaict that doesn't even have affinity.. /me wonders HTH that ended up on the runqueue so late.