diff options
Diffstat (limited to 'kernel/locking/mutex.c')
| -rw-r--r-- | kernel/locking/mutex.c | 7 |
1 files changed, 4 insertions, 3 deletions
diff --git a/kernel/locking/mutex.c b/kernel/locking/mutex.c index 4bd95465af55..e4d997bb7d70 100644 --- a/kernel/locking/mutex.c +++ b/kernel/locking/mutex.c @@ -432,7 +432,8 @@ __mutex_lock_common(struct mutex *lock, long state, unsigned int subclass, if (owner && !mutex_spin_on_owner(lock, owner)) break; - if ((atomic_read(&lock->count) == 1) && + /* Try to acquire the mutex if it is unlocked. */ + if (!mutex_is_locked(lock) && (atomic_cmpxchg(&lock->count, 1, 0) == 1)) { lock_acquired(&lock->dep_map, ip); if (use_ww_ctx) { @@ -479,9 +480,9 @@ slowpath: /* * Once more, try to acquire the lock. Only try-lock the mutex if - * lock->count >= 0 to reduce unnecessary xchg operations. + * it is unlocked to reduce unnecessary xchg() operations. */ - if (atomic_read(&lock->count) >= 0 && (atomic_xchg(&lock->count, 0) == 1)) + if (!mutex_is_locked(lock) && (atomic_xchg(&lock->count, 0) == 1)) goto skip_wait; debug_mutex_lock_common(lock, &waiter); |