Re: [PATCH 3/3] rtmutex: remove unnecessary adjust prio

From: Steven Rostedt <rostedt@goodmis.org>
To: Alex Shi <alex.shi@linaro.org>
Cc: peterz@infradead.org, mingo@redhat.com, corbet@lwn.net,
	linux-kernel@vger.kernel.org (open list:LOCKING PRIMITIVES),
	Sebastian Siewior <bigeasy@linutronix.de>,
	Thomas Gleixner <tglx@linutronix.de>
Subject: Re: [PATCH 3/3] rtmutex: remove unnecessary adjust prio
Date: Thu, 13 Apr 2017 12:15:30 -0400	[thread overview]
Message-ID: <20170413121530.394c6ca8@gandalf.local.home> (raw)
In-Reply-To: <1492092174-31734-4-git-send-email-alex.shi@linaro.org>

On Thu, 13 Apr 2017 22:02:54 +0800
Alex Shi <alex.shi@linaro.org> wrote:

> We don't need to adjust prio before new pi_waiter adding. The prio
> only need update after pi_waiter change or task normal_prio change.
> 
> Signed-off-by: Alex Shi <alex.shi@linaro.org>
> Cc: Steven Rostedt <rostedt@goodmis.org>
> Cc: Sebastian Siewior <bigeasy@linutronix.de>
> To: linux-kernel@vger.kernel.org
> To: Ingo Molnar <mingo@redhat.com>
> To: Peter Zijlstra <peterz@infradead.org>
> Cc: Thomas Gleixner <tglx@linutronix.de>
> ---
>  kernel/locking/rtmutex.c | 1 -
>  1 file changed, 1 deletion(-)
> 
> diff --git a/kernel/locking/rtmutex.c b/kernel/locking/rtmutex.c
> index 05ff685..3ee8bc1 100644
> --- a/kernel/locking/rtmutex.c
> +++ b/kernel/locking/rtmutex.c
> @@ -973,7 +973,6 @@ static int task_blocks_on_rt_mutex(struct rt_mutex *lock,
>  		return -EDEADLK;
>  
>  	raw_spin_lock(&task->pi_lock);
> -	__rt_mutex_adjust_prio(task);

Yeah, I'm not sure why this is called here.

-- Steve

>  	waiter->task = task;
>  	waiter->lock = lock;
>  	waiter->prio = task->prio;