diff options
Diffstat (limited to 'kernel/mutex.c')
| -rw-r--r-- | kernel/mutex.c | 20 |
1 files changed, 7 insertions, 13 deletions
diff --git a/kernel/mutex.c b/kernel/mutex.c index ff42e975590..5d79781394a 100644 --- a/kernel/mutex.c +++ b/kernel/mutex.c @@ -171,12 +171,6 @@ __mutex_lock_common(struct mutex *lock, long state, unsigned int subclass, struct thread_info *owner; /* - * If there are pending waiters, join them. - */ - if (!list_empty(&lock->wait_list)) - break; - - /* * If there's an owner, wait for it to either * release the lock or go to sleep. */ @@ -184,6 +178,13 @@ __mutex_lock_common(struct mutex *lock, long state, unsigned int subclass, if (owner && !mutex_spin_on_owner(lock, owner)) break; + if (atomic_cmpxchg(&lock->count, 1, 0) == 1) { + lock_acquired(&lock->dep_map, ip); + mutex_set_owner(lock); + preempt_enable(); + return 0; + } + /* * When there's no owner, we might have preempted between the * owner acquiring the lock and setting the owner field. If @@ -193,13 +194,6 @@ __mutex_lock_common(struct mutex *lock, long state, unsigned int subclass, if (!owner && (need_resched() || rt_task(task))) break; - if (atomic_cmpxchg(&lock->count, 1, 0) == 1) { - lock_acquired(&lock->dep_map, ip); - mutex_set_owner(lock); - preempt_enable(); - return 0; - } - /* * The cpu_relax() call is a compiler barrier which forces * everything in this loop to be re-loaded. We don't need |