From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932737AbdJKBJa (ORCPT ); Tue, 10 Oct 2017 21:09:30 -0400 Received: from omzsmtpe03.verizonbusiness.com ([199.249.25.208]:20248 "EHLO omzsmtpe03.verizonbusiness.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932363AbdJKAp6 (ORCPT ); Tue, 10 Oct 2017 20:45:58 -0400 From: "Levin, Alexander (Sasha Levin)" X-Host: surveyor.tdc.vzwcorp.com To: "gregkh@linuxfoundation.org" CC: "linux-kernel@vger.kernel.org" , "stable@vger.kernel.org" Subject: [GIT PULL for-4.9 15/48] sched/fair: Update rq clock before changing a task's CPU affinity Thread-Topic: [GIT PULL for-4.9 15/48] sched/fair: Update rq clock before changing a task's CPU affinity Thread-Index: AQHTQio4fSIap/zIGk6o2VEHHlGLLg== Date: Wed, 11 Oct 2017 00:45:22 +0000 Message-ID: <20171011004512.7949-16-alexander.levin@verizon.com> References: <20171011004512.7949-1-alexander.levin@verizon.com> In-Reply-To: <20171011004512.7949-1-alexander.levin@verizon.com> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-ms-exchange-messagesentrepresentingtype: 1 x-ms-exchange-transport-fromentityheader: Hosted x-originating-ip: [10.144.60.250] Content-Type: text/plain; charset="iso-8859-1" MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from quoted-printable to 8bit by nfs id v9B19aEF030724 From: Wanpeng Li [ Upstream commit a499c3ead88ccf147fc50689e85a530ad923ce36 ] 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 Signed-off-by: Sasha Levin --- kernel/sched/core.c | 1 + 1 file changed, 1 insertion(+) diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 2098954c690f..d271a1c387eb 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -1141,6 +1141,7 @@ 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) { /* -- 2.11.0