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-rw-r--r--kernel/mutex.c20
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