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authorPeter Zijlstra <peterz@infradead.org>2017-03-23 15:56:10 +0100
committerThomas Gleixner <tglx@linutronix.de>2017-04-04 11:44:05 +0200
commitaa2bfe55366552cb7e93e8709d66e698d79ccc47 (patch)
treec88ac6fbcf4a8ef48d40a1d9e40ff40ffeab0758 /kernel/locking/rtmutex.c
parent85e2d4f992868ad78dc8bb2c077b652fcfb3661a (diff)
downloadop-kernel-dev-aa2bfe55366552cb7e93e8709d66e698d79ccc47.zip
op-kernel-dev-aa2bfe55366552cb7e93e8709d66e698d79ccc47.tar.gz
rtmutex: Clean up
Previous patches changed the meaning of the return value of rt_mutex_slowunlock(); update comments and code to reflect this. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: juri.lelli@arm.com Cc: bigeasy@linutronix.de Cc: xlpang@redhat.com Cc: rostedt@goodmis.org Cc: mathieu.desnoyers@efficios.com Cc: jdesfossez@efficios.com Cc: bristot@redhat.com Link: http://lkml.kernel.org/r/20170323150216.255058238@infradead.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'kernel/locking/rtmutex.c')
-rw-r--r--kernel/locking/rtmutex.c28
1 files changed, 13 insertions, 15 deletions
diff --git a/kernel/locking/rtmutex.c b/kernel/locking/rtmutex.c
index 8faf472..4b1015e 100644
--- a/kernel/locking/rtmutex.c
+++ b/kernel/locking/rtmutex.c
@@ -1330,7 +1330,8 @@ static inline int rt_mutex_slowtrylock(struct rt_mutex *lock)
/*
* Slow path to release a rt-mutex.
- * Return whether the current task needs to undo a potential priority boosting.
+ *
+ * Return whether the current task needs to call rt_mutex_postunlock().
*/
static bool __sched rt_mutex_slowunlock(struct rt_mutex *lock,
struct wake_q_head *wake_q)
@@ -1401,8 +1402,7 @@ static bool __sched rt_mutex_slowunlock(struct rt_mutex *lock,
raw_spin_unlock_irqrestore(&lock->wait_lock, flags);
- /* check PI boosting */
- return true;
+ return true; /* call rt_mutex_postunlock() */
}
/*
@@ -1449,15 +1449,14 @@ rt_mutex_fasttrylock(struct rt_mutex *lock,
}
/*
- * Undo pi boosting (if necessary) and wake top waiter.
+ * Performs the wakeup of the the top-waiter and re-enables preemption.
*/
-void rt_mutex_postunlock(struct wake_q_head *wake_q, bool deboost)
+void rt_mutex_postunlock(struct wake_q_head *wake_q)
{
wake_up_q(wake_q);
/* Pairs with preempt_disable() in rt_mutex_slowunlock() */
- if (deboost)
- preempt_enable();
+ preempt_enable();
}
static inline void
@@ -1466,14 +1465,12 @@ rt_mutex_fastunlock(struct rt_mutex *lock,
struct wake_q_head *wqh))
{
DEFINE_WAKE_Q(wake_q);
- bool deboost;
if (likely(rt_mutex_cmpxchg_release(lock, current, NULL)))
return;
- deboost = slowfn(lock, &wake_q);
-
- rt_mutex_postunlock(&wake_q, deboost);
+ if (slowfn(lock, &wake_q))
+ rt_mutex_postunlock(&wake_q);
}
/**
@@ -1593,19 +1590,20 @@ bool __sched __rt_mutex_futex_unlock(struct rt_mutex *lock,
*/
preempt_disable();
- return true; /* deboost and wakeups */
+ return true; /* call postunlock() */
}
void __sched rt_mutex_futex_unlock(struct rt_mutex *lock)
{
DEFINE_WAKE_Q(wake_q);
- bool deboost;
+ bool postunlock;
raw_spin_lock_irq(&lock->wait_lock);
- deboost = __rt_mutex_futex_unlock(lock, &wake_q);
+ postunlock = __rt_mutex_futex_unlock(lock, &wake_q);
raw_spin_unlock_irq(&lock->wait_lock);
- rt_mutex_postunlock(&wake_q, deboost);
+ if (postunlock)
+ rt_mutex_postunlock(&wake_q);
}
/**
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