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-rw-r--r--kernel/locking/rtmutex.c31
1 files changed, 20 insertions, 11 deletions
diff --git a/kernel/locking/rtmutex.c b/kernel/locking/rtmutex.c
index fc605941b9b8..50bc93b3552f 100644
--- a/kernel/locking/rtmutex.c
+++ b/kernel/locking/rtmutex.c
@@ -960,22 +960,31 @@ rt_mutex_slowlock(struct rt_mutex *lock, int state,
/*
* Slow path try-lock function:
*/
-static inline int
-rt_mutex_slowtrylock(struct rt_mutex *lock)
+static inline int rt_mutex_slowtrylock(struct rt_mutex *lock)
{
- int ret = 0;
+ int ret;
+
+ /*
+ * If the lock already has an owner we fail to get the lock.
+ * This can be done without taking the @lock->wait_lock as
+ * it is only being read, and this is a trylock anyway.
+ */
+ if (rt_mutex_owner(lock))
+ return 0;
+ /*
+ * The mutex has currently no owner. Lock the wait lock and
+ * try to acquire the lock.
+ */
raw_spin_lock(&lock->wait_lock);
- if (likely(rt_mutex_owner(lock) != current)) {
+ ret = try_to_take_rt_mutex(lock, current, NULL);
- ret = try_to_take_rt_mutex(lock, current, NULL);
- /*
- * try_to_take_rt_mutex() sets the lock waiters
- * bit unconditionally. Clean this up.
- */
- fixup_rt_mutex_waiters(lock);
- }
+ /*
+ * try_to_take_rt_mutex() sets the lock waiters bit
+ * unconditionally. Clean this up.
+ */
+ fixup_rt_mutex_waiters(lock);
raw_spin_unlock(&lock->wait_lock);