From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751372AbdBXJSK (ORCPT ); Fri, 24 Feb 2017 04:18:10 -0500 Received: from terminus.zytor.com ([65.50.211.136]:50850 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751101AbdBXJSC (ORCPT ); Fri, 24 Feb 2017 04:18:02 -0500 Date: Fri, 24 Feb 2017 01:16:43 -0800 From: tip-bot for Wanpeng Li Message-ID: Cc: tglx@linutronix.de, matt@codeblueprint.co.uk, linux-kernel@vger.kernel.org, hpa@zytor.com, efault@gmx.de, wanpeng.li@hotmail.com, mingo@kernel.org, torvalds@linux-foundation.org, peterz@infradead.org Reply-To: efault@gmx.de, hpa@zytor.com, linux-kernel@vger.kernel.org, matt@codeblueprint.co.uk, tglx@linutronix.de, peterz@infradead.org, torvalds@linux-foundation.org, wanpeng.li@hotmail.com, mingo@kernel.org In-Reply-To: <1487749975-5994-1-git-send-email-wanpeng.li@hotmail.com> References: <1487749975-5994-1-git-send-email-wanpeng.li@hotmail.com> To: linux-tip-commits@vger.kernel.org Subject: [tip:sched/urgent] sched/fair: Update rq clock before changing a task's CPU affinity Git-Commit-ID: a499c3ead88ccf147fc50689e85a530ad923ce36 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: a499c3ead88ccf147fc50689e85a530ad923ce36 Gitweb: http://git.kernel.org/tip/a499c3ead88ccf147fc50689e85a530ad923ce36 Author: Wanpeng Li AuthorDate: Tue, 21 Feb 2017 23:52:55 -0800 Committer: Ingo Molnar CommitDate: Fri, 24 Feb 2017 08:58:33 +0100 sched/fair: Update rq clock before changing a task's CPU affinity This is triggered during boot when CONFIG_SCHED_DEBUG is enabled: ------------[ cut here ]------------ WARNING: CPU: 6 PID: 81 at kernel/sched/sched.h:812 set_next_entity+0x11d/0x380 rq->clock_update_flags < RQCF_ACT_SKIP CPU: 6 PID: 81 Comm: torture_shuffle Not tainted 4.10.0+ #1 Hardware name: LENOVO ThinkCentre M8500t-N000/SHARKBAY, BIOS FBKTC1AUS 02/16/2016 Call Trace: dump_stack+0x85/0xc2 __warn+0xcb/0xf0 warn_slowpath_fmt+0x5f/0x80 set_next_entity+0x11d/0x380 set_curr_task_fair+0x2b/0x60 do_set_cpus_allowed+0x139/0x180 __set_cpus_allowed_ptr+0x113/0x260 set_cpus_allowed_ptr+0x10/0x20 torture_shuffle+0xfd/0x180 kthread+0x10f/0x150 ? torture_shutdown_init+0x60/0x60 ? kthread_create_on_node+0x60/0x60 ret_from_fork+0x31/0x40 ---[ end trace dd94d92344cea9c6 ]--- The task is running && !queued, so there is no rq clock update before calling set_curr_task(). This patch fixes it by updating rq clock after holding rq->lock/pi_lock just as what other dequeue + put_prev + enqueue + set_curr story does. Signed-off-by: Wanpeng Li Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Matt Fleming Cc: Linus Torvalds Cc: Mike Galbraith Cc: Peter Zijlstra Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/1487749975-5994-1-git-send-email-wanpeng.li@hotmail.com Signed-off-by: Ingo Molnar --- kernel/sched/core.c | 1 + 1 file changed, 1 insertion(+) diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 2d6e828..cc1e3e0 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -1087,6 +1087,7 @@ static int __set_cpus_allowed_ptr(struct task_struct *p, int ret = 0; rq = task_rq_lock(p, &rf); + update_rq_clock(rq); if (p->flags & PF_KTHREAD) { /*