From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754518AbcDNLhs (ORCPT ); Thu, 14 Apr 2016 07:37:48 -0400 Received: from mx1.redhat.com ([209.132.183.28]:53454 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754426AbcDNLhq (ORCPT ); Thu, 14 Apr 2016 07:37:46 -0400 From: Xunlei Pang To: linux-kernel@vger.kernel.org Cc: Peter Zijlstra , Thomas Gleixner , Juri Lelli , Ingo Molnar , Steven Rostedt , Xunlei Pang Subject: [PATCH v3 6/6] sched/deadline/rtmutex: Don't miss the dl_runtime/dl_period update Date: Thu, 14 Apr 2016 19:37:07 +0800 Message-Id: <1460633827-345-7-git-send-email-xlpang@redhat.com> In-Reply-To: <1460633827-345-1-git-send-email-xlpang@redhat.com> References: <1460633827-345-1-git-send-email-xlpang@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Currently dl tasks will actually return at the very beginning of rt_mutex_adjust_prio_chain() in !detect_deadlock cases: if (waiter->prio == task->prio) { if (!detect_deadlock) goto out_unlock_pi; // out here else requeue = false; } As the deadline value of blocked deadline tasks(waiters) without changing their sched_class(thus prio doesn't change) never changes, this seems reasonable, but it actually misses the chance of updating rt_mutex_waiter's "dl_runtime(period)_copy" if a waiter updates its deadline parameters(dl_runtime, dl_period) or boosted waiter changes to !deadline class. Thus, force deadline task not out by adding the !dl_prio() condition. Signed-off-by: Xunlei Pang --- kernel/locking/rtmutex.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/locking/rtmutex.c b/kernel/locking/rtmutex.c index 4d14eee..f3b7d29 100644 --- a/kernel/locking/rtmutex.c +++ b/kernel/locking/rtmutex.c @@ -554,7 +554,7 @@ static int rt_mutex_adjust_prio_chain(struct task_struct *task, * enabled we continue, but stop the requeueing in the chain * walk. */ - if (waiter->prio == task->prio) { + if (waiter->prio == task->prio && !dl_task(task)) { if (!detect_deadlock) goto out_unlock_pi; else -- 1.8.3.1