From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752174AbdLBBhQ (ORCPT ); Fri, 1 Dec 2017 20:37:16 -0500 Received: from mail.kernel.org ([198.145.29.99]:48726 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751699AbdLBBhN (ORCPT ); Fri, 1 Dec 2017 20:37:13 -0500 DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org AFC47219A0 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=goodmis.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=rostedt@goodmis.org Message-Id: <20171202013711.705546858@goodmis.org> User-Agent: quilt/0.63-1 Date: Fri, 01 Dec 2017 20:37:01 -0500 From: Steven Rostedt To: linux-kernel@vger.kernel.org, linux-rt-users Cc: Thomas Gleixner , Carsten Emde , Sebastian Andrzej Siewior , John Kacur , Paul Gortmaker , Julia Cartwright , Daniel Wagner , tom.zanussi@linux.intel.com, Alex Shi , stable-rt@vger.kernel.org, Mike Galbraith Subject: [PATCH RT 3/9] kernel/hrtimer: migrate deferred timer on CPU down References: <20171202013658.149533964@goodmis.org> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15 Content-Disposition: inline; filename=0003-kernel-hrtimer-migrate-deferred-timer-on-CPU-down.patch Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.4.102-rt117-rc1 stable review patch. If anyone has any objections, please let me know. ------------------ From: Sebastian Andrzej Siewior hrtimers, which were deferred to the softirq context, and expire between softirq shutdown and hrtimer migration are dangling around. If the CPU goes back up the list head will be initialized and this corrupts the timer's list. It will remain unnoticed until a hrtimer_cancel(). This moves those timers so they will expire. Cc: stable-rt@vger.kernel.org Reported-by: Mike Galbraith Tested-by: Mike Galbraith Signed-off-by: Sebastian Andrzej Siewior --- kernel/time/hrtimer.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/kernel/time/hrtimer.c b/kernel/time/hrtimer.c index ba3d60144838..759913626eec 100644 --- a/kernel/time/hrtimer.c +++ b/kernel/time/hrtimer.c @@ -1880,6 +1880,11 @@ static void migrate_hrtimer_list(struct hrtimer_clock_base *old_base, */ enqueue_hrtimer(timer, new_base); } +#ifdef CONFIG_PREEMPT_RT_BASE + list_splice_tail(&old_base->expired, &new_base->expired); + if (!list_empty(&new_base->expired)) + raise_softirq_irqoff(HRTIMER_SOFTIRQ); +#endif } static void migrate_hrtimers(int scpu) -- 2.13.2