linux-kernel - Re: [PATCH v3 2/2] sched/rt: Remove unnecessary condition in push_rt

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Message-ID: <20170215214537.7936f336@grimm.local.home>
Date:   Wed, 15 Feb 2017 21:45:37 -0500
From:   Steven Rostedt <rostedt@...dmis.org>
To:     Byungchul Park <byungchul.park@....com>
Cc:     <peterz@...radead.org>, <mingo@...nel.org>,
        <linux-kernel@...r.kernel.org>, <juri.lelli@...il.com>,
        <kernel-team@....com>
Subject: Re: [PATCH v3 2/2] sched/rt: Remove unnecessary condition in
 push_rt_task()

On Thu, 16 Feb 2017 11:34:17 +0900
Byungchul Park <byungchul.park@....com> wrote:

> pick_next_pushable_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 code simpler.
> 
> By this patch, unnecessary one branch and two LOAD operations in 'if'
> statement can be avoided.
> 
> Signed-off-by: Byungchul Park <byungchul.park@....com>
> Reviewed-by: Steven Rostedt (VMware) <rostedt@...dmis.org>
> Reviewed-by: Juri Lelli <juri.lelli@....com>
> ---

This is a different patch, I don't believe Juri reviewed it yet.

-- Steve