From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751741AbdBOFWz (ORCPT ); Wed, 15 Feb 2017 00:22:55 -0500 Received: from LGEAMRELO12.lge.com ([156.147.23.52]:56077 "EHLO lgeamrelo12.lge.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750732AbdBOFWx (ORCPT ); Wed, 15 Feb 2017 00:22:53 -0500 X-Original-SENDERIP: 156.147.1.126 X-Original-MAILFROM: byungchul.park@lge.com X-Original-SENDERIP: 10.177.222.33 X-Original-MAILFROM: byungchul.park@lge.com Date: Wed, 15 Feb 2017 14:22:29 +0900 From: Byungchul Park To: peterz@infradead.org, mingo@kernel.org Cc: linux-kernel@vger.kernel.org, juri.lelli@gmail.com, kernel-team@lge.com Subject: Re: [PATCH] sched/deadline: Remove unnecessary condition in push_dl_task() Message-ID: <20170215052229.GR16086@X58A-UD3R> References: <1487135511-15817-1-git-send-email-byungchul.park@lge.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1487135511-15817-1-git-send-email-byungchul.park@lge.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Feb 15, 2017 at 02:11:51PM +0900, Byungchul Park wrote: > Once pick_next_pushable_dl_task(rq) return a task, it guarantees that > the task's cpu is rq->cpu, so task_cpu(next_task) is always rq->cpu if > task == next_task. Remove a redundant condition and make code simpler. Furthermore, unnecessary one branch and unnecessary two LOAD operations in 'if' statement can be avoided. > > Signed-off-by: Byungchul Park > --- > 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 27737f3..ad8d577 100644 > --- a/kernel/sched/deadline.c > +++ b/kernel/sched/deadline.c > @@ -1483,7 +1483,7 @@ static int push_dl_task(struct rq *rq) > * 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. > -- > 1.9.1