From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752985AbeBFL6o (ORCPT ); Tue, 6 Feb 2018 06:58:44 -0500 Received: from terminus.zytor.com ([65.50.211.136]:53713 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752879AbeBFL6f (ORCPT ); Tue, 6 Feb 2018 06:58:35 -0500 Date: Tue, 6 Feb 2018 03:55:07 -0800 From: tip-bot for Wen Yang Message-ID: Cc: peterz@infradead.org, efault@gmx.de, tglx@linutronix.de, mingo@kernel.org, linux-kernel@vger.kernel.org, jiang.biao2@zte.com.cn, hpa@zytor.com, torvalds@linux-foundation.org, wen.yang99@zte.com.cn Reply-To: tglx@linutronix.de, efault@gmx.de, peterz@infradead.org, jiang.biao2@zte.com.cn, linux-kernel@vger.kernel.org, hpa@zytor.com, torvalds@linux-foundation.org, wen.yang99@zte.com.cn, mingo@kernel.org In-Reply-To: <1517800721-42092-1-git-send-email-wen.yang99@zte.com.cn> References: <1517800721-42092-1-git-send-email-wen.yang99@zte.com.cn> To: linux-tip-commits@vger.kernel.org Subject: [tip:sched/urgent] sched/rt: Make update_curr_rt() more accurate Git-Commit-ID: e7ad203166fff89b1d8253faf68fbe6966bf7181 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: e7ad203166fff89b1d8253faf68fbe6966bf7181 Gitweb: https://git.kernel.org/tip/e7ad203166fff89b1d8253faf68fbe6966bf7181 Author: Wen Yang AuthorDate: Mon, 5 Feb 2018 11:18:41 +0800 Committer: Ingo Molnar CommitDate: Tue, 6 Feb 2018 10:20:34 +0100 sched/rt: Make update_curr_rt() more accurate rq->clock_task may be updated between the two calls of rq_clock_task() in update_curr_rt(). Calling rq_clock_task() only once makes it more accurate and efficient, taking update_curr() as reference. Signed-off-by: Wen Yang Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Jiang Biao Cc: Linus Torvalds Cc: Mike Galbraith Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: zhong.weidong@zte.com.cn Link: http://lkml.kernel.org/r/1517800721-42092-1-git-send-email-wen.yang99@zte.com.cn Signed-off-by: Ingo Molnar --- kernel/sched/rt.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c index 89a086e..663b235 100644 --- a/kernel/sched/rt.c +++ b/kernel/sched/rt.c @@ -950,12 +950,13 @@ static void update_curr_rt(struct rq *rq) { struct task_struct *curr = rq->curr; struct sched_rt_entity *rt_se = &curr->rt; + u64 now = rq_clock_task(rq); u64 delta_exec; if (curr->sched_class != &rt_sched_class) return; - delta_exec = rq_clock_task(rq) - curr->se.exec_start; + delta_exec = now - curr->se.exec_start; if (unlikely((s64)delta_exec <= 0)) return; @@ -968,7 +969,7 @@ static void update_curr_rt(struct rq *rq) curr->se.sum_exec_runtime += delta_exec; account_group_exec_runtime(curr, delta_exec); - curr->se.exec_start = rq_clock_task(rq); + curr->se.exec_start = now; cgroup_account_cputime(curr, delta_exec); sched_rt_avg_update(rq, delta_exec);