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=-19.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT 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 BDC74C433F5 for ; Mon, 6 Sep 2021 01:30:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9F09D610F7 for ; Mon, 6 Sep 2021 01:30:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239573AbhIFBb5 (ORCPT ); Sun, 5 Sep 2021 21:31:57 -0400 Received: from mail.kernel.org ([198.145.29.99]:47610 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241092AbhIFB1l (ORCPT ); Sun, 5 Sep 2021 21:27:41 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 91EEE610F7; Mon, 6 Sep 2021 01:22:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1630891373; bh=lCEqwOHgy8VyTFJn1sav7f7GkOc6F4tEJaOHo6rs8ro=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=JFhKmquheowM8GgQBTUtppzZHPk0WZlh4XUNuqvklSIuL9UgcL8Mh8VAf5BJBwmqx /0r/faa798b1Xvtx7wbWLorgOjVcNmI/E3DR9UlP0lw2o8iXZMqykpf2+btt4EGIcJ XIAlrqZtb55Chmqv/r48rorArO7ZISvclYyRXgbeQ9mCf9v6QbLEUNbpxCTQHEMmDW 5i3rxqumie1hHY5xq9aT1v7XL+dj7mKWWSfqxK7lUrK2taOMbWXlJkCvN51ZO6geJq dxcdF86m6qgvsjlKAbo0Og2Ldsr23RholJg4Qb/j7zArj7y8rkm7pZrtbKl5jTymdv STMEkEDVhkY3Q== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Dietmar Eggemann , Bruno Goncalves , Peter Zijlstra , Daniel Bristot de Oliveira , Juri Lelli , Sasha Levin Subject: [PATCH AUTOSEL 5.4 07/30] sched/deadline: Fix missing clock update in migrate_task_rq_dl() Date: Sun, 5 Sep 2021 21:22:20 -0400 Message-Id: <20210906012244.930338-7-sashal@kernel.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210906012244.930338-1-sashal@kernel.org> References: <20210906012244.930338-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Dietmar Eggemann [ Upstream commit b4da13aa28d4fd0071247b7b41c579ee8a86c81a ] 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 Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Daniel Bristot de Oliveira Acked-by: Juri Lelli Link: https://lore.kernel.org/r/20210804135925.3734605-1-dietmar.eggemann@arm.com Signed-off-by: Sasha Levin --- kernel/sched/deadline.c | 1 + 1 file changed, 1 insertion(+) diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c index 7ab0b80cb12d..2bda9fdba31c 100644 --- a/kernel/sched/deadline.c +++ b/kernel/sched/deadline.c @@ -1654,6 +1654,7 @@ static void migrate_task_rq_dl(struct task_struct *p, int new_cpu __maybe_unused */ raw_spin_lock(&rq->lock); if (p->dl.dl_non_contending) { + update_rq_clock(rq); sub_running_bw(&p->dl, &rq->dl); p->dl.dl_non_contending = 0; /* -- 2.30.2