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=-3.8 required=3.0 tests=BAYES_00, 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 DEF31C433DB for ; Thu, 14 Jan 2021 10:38:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A0E4423A3B for ; Thu, 14 Jan 2021 10:38:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727116AbhANKi1 (ORCPT ); Thu, 14 Jan 2021 05:38:27 -0500 Received: from foss.arm.com ([217.140.110.172]:47446 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725954AbhANKi1 (ORCPT ); Thu, 14 Jan 2021 05:38:27 -0500 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 402451FB; Thu, 14 Jan 2021 02:37:42 -0800 (PST) Received: from e113632-lin (e113632-lin.cambridge.arm.com [10.1.194.46]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 9FCE93F70D; Thu, 14 Jan 2021 02:37:40 -0800 (PST) From: Valentin Schneider To: paulmck@kernel.org Cc: linux-kernel@vger.kernel.org, peterz@infradead.org, mingo@kernel.org, tglx@linutronix.de, jiangshanlai@gmail.com, cai@redhat.com, vincent.donnefort@arm.com, decui@microsoft.com, vincent.guittot@linaro.org, rostedt@goodmis.org, tj@kernel.org Subject: Re: [PATCH] sched/core: Print out straggler tasks in sched_cpu_dying() In-Reply-To: <20210114003613.GD2743@paulmck-ThinkPad-P72> References: <20210113183141.11974-1-valentin.schneider@arm.com> <20210113220244.GC2743@paulmck-ThinkPad-P72> <20210114003613.GD2743@paulmck-ThinkPad-P72> User-Agent: Notmuch/0.21 (http://notmuchmail.org) Emacs/26.3 (x86_64-pc-linux-gnu) Date: Thu, 14 Jan 2021 10:37:35 +0000 Message-ID: MIME-Version: 1.0 Content-Type: text/plain Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 13/01/21 16:36, Paul E. McKenney wrote: > On Thu, Jan 14, 2021 at 12:15:24AM +0000, Valentin Schneider wrote: >> On 13/01/21 14:02, Paul E. McKenney wrote: >> Thanks for giving it a spin! I think with the current series (either >> Lai's or Peter's) sched_cpu_dying() should go smoothly, but you never >> know. > > I was running the patch set having one of Lai's and three of Peter's, > which sounds like Peter's. That's how I was seeing it :) > If I understand which series is which, > Peter's has the advantage of not requiring rcutorture changes. ;-) > >> > However, it did produce the following new-to-me splat, which will >> > hopefully be of some help. >> > >> > Thanx, Paul >> > >> > ------------------------------------------------------------------------ >> > >> > WARNING: CPU: 2 PID: 23 at kernel/kthread.c:508 kthread_set_per_cpu+0x3b/0x50 >> >> Aha, so that's that warning I was expecting to see [1]. >> Did you also get the process_one_work() one? > > Yes. Of 112 one-hour runs, there were five process_one_work() splats > and two kthread_set_per_cpu() splats. Each splat-ridden run had exactly > one splat. > I was expecting to see both in one run, so am still somewhat confused.