From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755136AbeEaM3c (ORCPT ); Thu, 31 May 2018 08:29:32 -0400 Received: from terminus.zytor.com ([198.137.202.136]:34275 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755110AbeEaM33 (ORCPT ); Thu, 31 May 2018 08:29:29 -0400 Date: Thu, 31 May 2018 05:29:03 -0700 From: tip-bot for Juri Lelli Message-ID: Cc: claudio@evidence.eu.com, luca.abeni@santannapisa.it, hpa@zytor.com, xiaolong.ye@intel.com, linux-kernel@vger.kernel.org, juri.lelli@redhat.com, tglx@linutronix.de, torvalds@linux-foundation.org, mingo@kernel.org, peterz@infradead.org Reply-To: claudio@evidence.eu.com, hpa@zytor.com, luca.abeni@santannapisa.it, xiaolong.ye@intel.com, juri.lelli@redhat.com, linux-kernel@vger.kernel.org, peterz@infradead.org, mingo@kernel.org, torvalds@linux-foundation.org, tglx@linutronix.de In-Reply-To: <20180530160809.9074-1-juri.lelli@redhat.com> References: <20180530160809.9074-1-juri.lelli@redhat.com> To: linux-tip-commits@vger.kernel.org Subject: [tip:sched/urgent] sched/deadline: Fix missing clock update Git-Commit-ID: ecda2b66e263dfd6c1d6113add19150f4e235bb3 X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: ecda2b66e263dfd6c1d6113add19150f4e235bb3 Gitweb: https://git.kernel.org/tip/ecda2b66e263dfd6c1d6113add19150f4e235bb3 Author: Juri Lelli AuthorDate: Wed, 30 May 2018 18:08:09 +0200 Committer: Ingo Molnar CommitDate: Thu, 31 May 2018 12:27:13 +0200 sched/deadline: Fix missing clock update A missing clock update is causing the following warning: rq->clock_update_flags < RQCF_ACT_SKIP WARNING: CPU: 10 PID: 0 at kernel/sched/sched.h:963 inactive_task_timer+0x5d6/0x720 Call Trace: __hrtimer_run_queues+0x10f/0x530 hrtimer_interrupt+0xe5/0x240 smp_apic_timer_interrupt+0x79/0x2b0 apic_timer_interrupt+0xf/0x20 do_idle+0x203/0x280 cpu_startup_entry+0x6f/0x80 start_secondary+0x1b0/0x200 secondary_startup_64+0xa5/0xb0 hardirqs last enabled at (793919): [] cpuidle_enter_state+0x9e/0x360 hardirqs last disabled at (793920): [] interrupt_entry+0xce/0xe0 softirqs last enabled at (793922): [] irq_enter+0x68/0x70 softirqs last disabled at (793921): [] irq_enter+0x4d/0x70 This happens because inactive_task_timer() calls sub_running_bw() (if TASK_DEAD and non_contending) that might trigger a schedutil update, which might access the clock. Clock is however currently updated only later in inactive_task_timer() function. Fix the problem by updating the clock right after task_rq_lock(). Reported-by: kernel test robot Signed-off-by: Juri Lelli Signed-off-by: Peter Zijlstra (Intel) Cc: Claudio Scordino Cc: Linus Torvalds Cc: Luca Abeni Cc: Peter Zijlstra Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/20180530160809.9074-1-juri.lelli@redhat.com Signed-off-by: Ingo Molnar --- kernel/sched/deadline.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c index 1356afd1eeb6..fbfc3f1d368a 100644 --- a/kernel/sched/deadline.c +++ b/kernel/sched/deadline.c @@ -1259,6 +1259,9 @@ static enum hrtimer_restart inactive_task_timer(struct hrtimer *timer) rq = task_rq_lock(p, &rf); + sched_clock_tick(); + update_rq_clock(rq); + if (!dl_task(p) || p->state == TASK_DEAD) { struct dl_bw *dl_b = dl_bw_of(task_cpu(p)); @@ -1278,9 +1281,6 @@ static enum hrtimer_restart inactive_task_timer(struct hrtimer *timer) if (dl_se->dl_non_contending == 0) goto unlock; - sched_clock_tick(); - update_rq_clock(rq); - sub_running_bw(dl_se, &rq->dl); dl_se->dl_non_contending = 0; unlock: