[PATCH] rtmutex: remove unnecessary adjust prio

From: Alex Shi
Date: Thu Jul 13 2017 - 02:19:26 EST


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.

Steven Rostedt pointed:
"Interesting, I did some git mining and this was added with the original
entry of the rtmutex.c (23f78d4a0). Looking at even that version, I
don't see the purpose of adjusting the task prio here. It is done
before anything changes in the task."

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>
Reviewed-by: Steven Rostedt (VMware) <rostedt@xxxxxxxxxxx>
---
kernel/locking/rtmutex.c | 1 -
1 file changed, 1 deletion(-)

diff --git a/kernel/locking/rtmutex.c b/kernel/locking/rtmutex.c
index 28cd09e..d1fe41f 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;
--
2.7.4