From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S966947AbdEWItH (ORCPT ); Tue, 23 May 2017 04:49:07 -0400 Received: from terminus.zytor.com ([65.50.211.136]:39629 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S966910AbdEWItF (ORCPT ); Tue, 23 May 2017 04:49:05 -0400 Date: Tue, 23 May 2017 01:45:24 -0700 From: tip-bot for Byungchul Park Message-ID: Cc: kernel-team@lge.com, hpa@zytor.com, peterz@infradead.org, linux-kernel@vger.kernel.org, rostedt@goodmis.org, byungchul.park@lge.com, tglx@linutronix.de, bristot@redhat.com, mingo@kernel.org, torvalds@linux-foundation.org, juri.lelli@arm.com Reply-To: mingo@kernel.org, tglx@linutronix.de, bristot@redhat.com, juri.lelli@arm.com, torvalds@linux-foundation.org, hpa@zytor.com, peterz@infradead.org, kernel-team@lge.com, rostedt@goodmis.org, byungchul.park@lge.com, linux-kernel@vger.kernel.org In-Reply-To: <1494551159-22367-1-git-send-email-byungchul.park@lge.com> References: <1494551159-22367-1-git-send-email-byungchul.park@lge.com> To: linux-tip-commits@vger.kernel.org Subject: [tip:sched/core] sched/deadline: Remove unnecessary condition in push_dl_task() Git-Commit-ID: a776b968e52895a350d636e6e7fdcb3b10846fa4 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: a776b968e52895a350d636e6e7fdcb3b10846fa4 Gitweb: http://git.kernel.org/tip/a776b968e52895a350d636e6e7fdcb3b10846fa4 Author: Byungchul Park AuthorDate: Fri, 12 May 2017 10:05:59 +0900 Committer: Ingo Molnar CommitDate: Tue, 23 May 2017 10:01:33 +0200 sched/deadline: Remove unnecessary condition in push_dl_task() pick_next_pushable_dl_task(rq) has BUG_ON(rq->cpu != task_cpu(task)) when it returns a task other than NULL, which means that task_cpu(task) must be rq->cpu. So if task == next_task, then task_cpu(next_task) must be rq->cpu as well. Remove the redundant condition and make the code simpler. This way one unnecessary branch and two LOAD operations can be avoided. Signed-off-by: Byungchul Park Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Steven Rostedt (VMware) Reviewed-by: Juri Lelli Reviewed-by: Daniel Bristot de Oliveira Cc: Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/1494551159-22367-1-git-send-email-byungchul.park@lge.com Signed-off-by: Ingo Molnar --- kernel/sched/deadline.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c index a2ce590..df6c291 100644 --- a/kernel/sched/deadline.c +++ b/kernel/sched/deadline.c @@ -1533,7 +1533,7 @@ retry: * then possible that next_task has migrated. */ task = pick_next_pushable_dl_task(rq); - if (task_cpu(next_task) == rq->cpu && task == next_task) { + if (task == next_task) { /* * The task is still there. We don't try * again, some other cpu will pull it when ready.