From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752347AbdBJIfT (ORCPT ); Fri, 10 Feb 2017 03:35:19 -0500 Received: from terminus.zytor.com ([65.50.211.136]:53196 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752248AbdBJIeS (ORCPT ); Fri, 10 Feb 2017 03:34:18 -0500 Date: Fri, 10 Feb 2017 00:33:21 -0800 From: "tip-bot for Steven Rostedt (VMware)" Message-ID: Cc: torvalds@linux-foundation.org, oleg@redhat.com, peterz@infradead.org, vincent.guittot@linaro.org, tglx@linutronix.de, rostedt@goodmis.org, linux-kernel@vger.kernel.org, akpm@linux-foundation.org, hpa@zytor.com, mingo@kernel.org Reply-To: torvalds@linux-foundation.org, oleg@redhat.com, tglx@linutronix.de, vincent.guittot@linaro.org, peterz@infradead.org, mingo@kernel.org, hpa@zytor.com, akpm@linux-foundation.org, linux-kernel@vger.kernel.org, rostedt@goodmis.org In-Reply-To: <20170206110426.27ca6426@gandalf.local.home> References: <20170206110426.27ca6426@gandalf.local.home> To: linux-tip-commits@vger.kernel.org Subject: [tip:sched/core] sched/core: Remove unlikely() annotation from sched_move_task() Git-Commit-ID: bb3bac2ca9a3a5b7fa601781adf70167a0449d75 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: bb3bac2ca9a3a5b7fa601781adf70167a0449d75 Gitweb: http://git.kernel.org/tip/bb3bac2ca9a3a5b7fa601781adf70167a0449d75 Author: Steven Rostedt (VMware) AuthorDate: Mon, 6 Feb 2017 11:04:26 -0500 Committer: Ingo Molnar CommitDate: Fri, 10 Feb 2017 09:05:42 +0100 sched/core: Remove unlikely() annotation from sched_move_task() The check for 'running' in sched_move_task() has an unlikely() around it. That is, it is unlikely that the task being moved is running. That use to be true. But with a couple of recent updates, it is now likely that the task will be running. The first change came from ea86cb4b7621 ("sched/cgroup: Fix cpu_cgroup_fork() handling") that moved around the use case of sched_move_task() in do_fork() where the call is now done after the task is woken (hence it is running). The second change came from 8e5bfa8c1f84 ("sched/autogroup: Do not use autogroup->tg in zombie threads") where sched_move_task() is called by the exit path, by the task that is exiting. Hence it too is running. Signed-off-by: Steven Rostedt (VMware) Signed-off-by: Peter Zijlstra (Intel) Cc: Andrew Morton Cc: Linus Torvalds Cc: Oleg Nesterov Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: Vincent Guittot Link: http://lkml.kernel.org/r/20170206110426.27ca6426@gandalf.local.home Signed-off-by: Ingo Molnar --- kernel/sched/core.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/kernel/sched/core.c b/kernel/sched/core.c index e4aa470..34e2291 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -6404,14 +6404,14 @@ void sched_move_task(struct task_struct *tsk) if (queued) dequeue_task(rq, tsk, DEQUEUE_SAVE | DEQUEUE_MOVE); - if (unlikely(running)) + if (running) put_prev_task(rq, tsk); sched_change_group(tsk, TASK_MOVE_GROUP); if (queued) enqueue_task(rq, tsk, ENQUEUE_RESTORE | ENQUEUE_MOVE); - if (unlikely(running)) + if (running) set_curr_task(rq, tsk); task_rq_unlock(rq, tsk, &rf);