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, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,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 ED03AC4742C for ; Mon, 16 Nov 2020 10:40:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A569220789 for ; Mon, 16 Nov 2020 10:40:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726710AbgKPKAW (ORCPT ); Mon, 16 Nov 2020 05:00:22 -0500 Received: from foss.arm.com ([217.140.110.172]:36976 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726236AbgKPKAW (ORCPT ); Mon, 16 Nov 2020 05:00:22 -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 4657A31B; Mon, 16 Nov 2020 02:00:21 -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 6156E3F718; Mon, 16 Nov 2020 02:00:20 -0800 (PST) References: User-agent: mu4e 0.9.17; emacs 26.3 From: Valentin Schneider To: Oleksandr Natalenko Cc: linux-rt-users@vger.kernel.org, linux-kernel@vger.kernel.org, tglx@linutronix.de, peterz@infradead.org, rostedt@goodmis.org Subject: Re: WARNING at kernel/sched/core.c:2013 migration_cpu_stop+0x2e3/0x330 Message-ID: In-reply-to: Date: Mon, 16 Nov 2020 10:00:14 +0000 MIME-Version: 1.0 Content-Type: text/plain Precedence: bulk List-ID: X-Mailing-List: linux-rt-users@vger.kernel.org On 15/11/20 22:32, Oleksandr Natalenko wrote: > Hi. > > I'm running v5.10-rc3-rt7 for some time, and I came across this splat in > dmesg: > > ``` > [118769.951010] ------------[ cut here ]------------ > [118769.951013] WARNING: CPU: 19 PID: 146 at kernel/sched/core.c:2013 Err, I didn't pick up on this back then, but isn't that check bogus? If the task is enqueued elsewhere, it's valid for it not to be affined 'here'. Also that is_migration_disabled() check within is_cpu_allowed() makes me think this isn't the best thing to call on a remote task. --- diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 1218f3ce1713..47d5b677585f 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -2010,7 +2010,7 @@ static int migration_cpu_stop(void *data) * valid again. Nothing to do. */ if (!pending) { - WARN_ON_ONCE(!is_cpu_allowed(p, cpu_of(rq))); + WARN_ON_ONCE(!cpumask_test_cpu(task_cpu(p), p->cpus_ptr)); goto out; }