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

From: Alex Shi
Date: Mon Jun 19 2017 - 20:40:51 EST


CC fengguang.

This patch survived in Fengguang's 0day testing on
https://github.com/alexshi/power-scheduling.git rtmutex-doc :)

Regards
Alex

On 05/25/2017 01:26 PM, Alex Shi wrote:
> We don't need to adjust prio before new pi_waiter adding. The prio
> only need update after pi_waiter change or task priority change.
>
> Signed-off-by: Alex Shi <alex.shi@xxxxxxxxxx>
> Cc: Steven Rostedt <rostedt@xxxxxxxxxxx>
> Cc: Sebastian Siewior <bigeasy@xxxxxxxxxxxxx>
> Cc: Mathieu Poirier <mathieu.poirier@xxxxxxxxxx>
> Cc: Juri Lelli <juri.lelli@xxxxxxx>
> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> To: linux-kernel@xxxxxxxxxxxxxxx
> To: Ingo Molnar <mingo@xxxxxxxxxx>
> To: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
> ---
> kernel/locking/rtmutex.c | 1 -
> 1 file changed, 1 deletion(-)
>
> diff --git a/kernel/locking/rtmutex.c b/kernel/locking/rtmutex.c
> index b955094..b659ba0 100644
> --- a/kernel/locking/rtmutex.c
> +++ b/kernel/locking/rtmutex.c
> @@ -963,7 +963,6 @@ static int task_blocks_on_rt_mutex(struct rt_mutex *lock,
> return -EDEADLK;
>
> raw_spin_lock(&task->pi_lock);
> - rt_mutex_adjust_prio(task);
> waiter->task = task;
> waiter->lock = lock;
> waiter->prio = task->prio;
>