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

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Message-ID: <20170216030302.GU16086@X58A-UD3R>
Date:   Thu, 16 Feb 2017 12:03:02 +0900
From:   Byungchul Park <byungchul.park@....com>
To:     Steven Rostedt <rostedt@...dmis.org>
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 Wed, Feb 15, 2017 at 09:45:37PM -0500, Steven Rostedt wrote:
> 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.

I will take care not to make this kind of mistake next time.

Thank you very much.

> 
> -- Steve