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rtmutex: Simplify remove_waiter() 

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

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Steven Rostedt <rostedt@goodmis.org>
Reviewed-by: Lai Jiangshan <laijs@cn.fujitsu.com>
This commit is contained in:
Thomas Gleixner 2014-06-07 09:36:13 +02:00
parent 3eb65aeadf
commit 1ca7b86062
1 changed files with 19 additions and 17 deletions
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36
kernel/locking/rtmutex.c
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@ -917,9 +917,9 @@ static void wakeup_next_waiter(struct rt_mutex *lock)
static void remove_waiter(struct rt_mutex *lock,
struct rt_mutex_waiter *waiter)
{
int first = (waiter == rt_mutex_top_waiter(lock));
bool is_top_waiter = (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);
@ -927,29 +927,31 @@ static void remove_waiter(struct rt_mutex *lock,
current->pi_blocked_on = NULL;
raw_spin_unlock_irqrestore(&current->pi_lock, flags);
if (!owner)
/*
* Only update priority if the waiter was the highest priority
* waiter of the lock and there is an owner to update.
*/
if (!owner || !is_top_waiter)
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);
/*
* Don't walk the chain, if the owner task is not blocked
* itself.
*/
if (!next_lock)
return;