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_CR_TRAILER, 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 63C86C4338F for ; Thu, 5 Aug 2021 09:36:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2F69A60C41 for ; Thu, 5 Aug 2021 09:36:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232810AbhHEJg5 (ORCPT ); Thu, 5 Aug 2021 05:36:57 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59336 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232605AbhHEJg5 (ORCPT ); Thu, 5 Aug 2021 05:36:57 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B784DC061765 for ; Thu, 5 Aug 2021 02:36:42 -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=3XEEDb3hLIq11X5odcZdLZhPWWsD1ywJ/nuhepSVgpA=; b=c2MXMV0ZnZtSE3YjcEih1vErmz hOReUlzYqCAy4aIDtYSuj/kCu5FZQ+o+1RH6phwCrG4Y8MtPU2c2ns9D/q2rH2RMC8cTT+innKZZO M9ZDzH7f5rUsZ8/JRF6WRDdVe4bVdfo1t5tXPQFymJLB2cD/mPR+E1HHDzRVNvkRX7IkHvTtCcxaw Oz6A8AYK0e9ecaNPGxvg61RTGQPvKQBVAPyhIAvggCLzEEYMhBfrSxYtJmijYZL67SnVdsmnfGDum L2IYfw48do8+TPSemf+4Ufdcwdn2MQ6VWOzLbWTfEdz8m8sefK4+nL0DSjXoQgdPscX8oz+AFTKWD gUMd0ZiQ==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=worktop.programming.kicks-ass.net) by casper.infradead.org with esmtpsa (Exim 4.94.2 #2 (Red Hat Linux)) id 1mBZmz-006oIj-2a; Thu, 05 Aug 2021 09:35:55 +0000 Received: by worktop.programming.kicks-ass.net (Postfix, from userid 1000) id 5486B9862B0; Thu, 5 Aug 2021 11:35:44 +0200 (CEST) Date: Thu, 5 Aug 2021 11:35:44 +0200 From: Peter Zijlstra To: Daniel Bristot de Oliveira Cc: Dietmar Eggemann , Ingo Molnar , Juri Lelli , Steven Rostedt , Vincent Guittot , Bruno Goncalves , linux-kernel@vger.kernel.org Subject: Re: [PATCH] sched/deadline: Fix missing clock update in migrate_task_rq_dl() Message-ID: <20210805093544.GC22037@worktop.programming.kicks-ass.net> References: <20210804135925.3734605-1-dietmar.eggemann@arm.com> <57f2dfe5-c1f5-4efb-e565-2e174228ee9a@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <57f2dfe5-c1f5-4efb-e565-2e174228ee9a@redhat.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Aug 05, 2021 at 10:16:26AM +0200, Daniel Bristot de Oliveira wrote: > On 8/4/21 3:59 PM, Dietmar Eggemann wrote: > > A missing clock update is causing the following warning: > > > > rq->clock_update_flags < RQCF_ACT_SKIP > > WARNING: CPU: 112 PID: 2041 at kernel/sched/sched.h:1453 > > sub_running_bw.isra.0+0x190/0x1a0 > > ... > > CPU: 112 PID: 2041 Comm: sugov:112 Tainted: G W 5.14.0-rc1 #1 > > Hardware name: WIWYNN Mt.Jade Server System > > B81.030Z1.0007/Mt.Jade Motherboard, BIOS 1.6.20210526 (SCP: > > 1.06.20210526) 2021/05/26 > > ... > > Call trace: > > sub_running_bw.isra.0+0x190/0x1a0 > > migrate_task_rq_dl+0xf8/0x1e0 > > set_task_cpu+0xa8/0x1f0 > > try_to_wake_up+0x150/0x3d4 > > wake_up_q+0x64/0xc0 > > __up_write+0xd0/0x1c0 > > up_write+0x4c/0x2b0 > > cppc_set_perf+0x120/0x2d0 > > cppc_cpufreq_set_target+0xe0/0x1a4 [cppc_cpufreq] > > __cpufreq_driver_target+0x74/0x140 > > sugov_work+0x64/0x80 > > kthread_worker_fn+0xe0/0x230 > > kthread+0x138/0x140 > > ret_from_fork+0x10/0x18 > > > > The task causing this is the `cppc_fie` DL task introduced by > > commit 1eb5dde674f5 ("cpufreq: CPPC: Add support for frequency > > invariance"). > > > > With CONFIG_ACPI_CPPC_CPUFREQ_FIE=y and schedutil cpufreq governor on > > slow-switching system (like on this Ampere Altra WIWYNN Mt. Jade Arm > > Server): > > > > DL task `curr=sugov:112` lets `p=cppc_fie` migrate and since the latter > > is in `non_contending` state, migrate_task_rq_dl() calls > > > > sub_running_bw()->__sub_running_bw()->cpufreq_update_util()-> > > rq_clock()->assert_clock_updated() > > > > on p. > > > > Fix this by updating the clock for a non_contending task in > > migrate_task_rq_dl() before calling sub_running_bw(). > > > > Reported-by: Bruno Goncalves > > Signed-off-by: Dietmar Eggemann > > Reviewed-by: Daniel Bristot de Oliveira Thanks!