[patch V3 4/7] rtmutex: Siplify remove_waiter()

From: Thomas Gleixner
Date: Mon Jun 09 2014 - 16:28:28 EST


Exit right away, when the removed waiter was not the top prioriy
waiter on the lock. Get rid of the extra indent level.

Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
---
kernel/locking/rtmutex.c | 26 ++++++++++----------------
1 file changed, 10 insertions(+), 16 deletions(-)

Index: tip/kernel/locking/rtmutex.c
===================================================================
--- tip.orig/kernel/locking/rtmutex.c
+++ tip/kernel/locking/rtmutex.c
@@ -780,7 +780,7 @@ static void remove_waiter(struct rt_mute
{
int first = (waiter == rt_mutex_top_waiter(lock));
struct task_struct *owner = rt_mutex_owner(lock);
- struct rt_mutex *next_lock = NULL;
+ struct rt_mutex *next_lock;
unsigned long flags;

raw_spin_lock_irqsave(&current->pi_lock, flags);
@@ -788,28 +788,22 @@ static void remove_waiter(struct rt_mute
current->pi_blocked_on = NULL;
raw_spin_unlock_irqrestore(&current->pi_lock, flags);

- if (!owner)
+ if (!owner || !first)
return;

- if (first) {
+ raw_spin_lock_irqsave(&owner->pi_lock, flags);

- raw_spin_lock_irqsave(&owner->pi_lock, flags);
+ rt_mutex_dequeue_pi(owner, waiter);

- rt_mutex_dequeue_pi(owner, waiter);
+ if (rt_mutex_has_waiters(lock))
+ rt_mutex_enqueue_pi(owner, rt_mutex_top_waiter(lock));

- if (rt_mutex_has_waiters(lock)) {
- struct rt_mutex_waiter *next;
+ __rt_mutex_adjust_prio(owner);

- next = rt_mutex_top_waiter(lock);
- rt_mutex_enqueue_pi(owner, next);
- }
- __rt_mutex_adjust_prio(owner);
+ /* Store the lock on which owner is blocked or NULL */
+ next_lock = task_blocked_on_lock(owner);

- /* Store the lock on which owner is blocked or NULL */
- next_lock = task_blocked_on_lock(owner);
-
- raw_spin_unlock_irqrestore(&owner->pi_lock, flags);
- }
+ raw_spin_unlock_irqrestore(&owner->pi_lock, flags);

if (!next_lock)
return;


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