diff options
| -rw-r--r-- | include/asm-generic/mutex-xchg.h | 11 |
1 files changed, 9 insertions, 2 deletions
diff --git a/include/asm-generic/mutex-xchg.h b/include/asm-generic/mutex-xchg.h index 580a6d35c700..c04e0db8a2d6 100644 --- a/include/asm-generic/mutex-xchg.h +++ b/include/asm-generic/mutex-xchg.h @@ -26,7 +26,13 @@ static inline void __mutex_fastpath_lock(atomic_t *count, void (*fail_fn)(atomic_t *)) { if (unlikely(atomic_xchg(count, 0) != 1)) - fail_fn(count); + /* + * We failed to acquire the lock, so mark it contended + * to ensure that any waiting tasks are woken up by the + * unlock slow path. + */ + if (likely(atomic_xchg(count, -1) != 1)) + fail_fn(count); } /** @@ -43,7 +49,8 @@ static inline int __mutex_fastpath_lock_retval(atomic_t *count, int (*fail_fn)(atomic_t *)) { if (unlikely(atomic_xchg(count, 0) != 1)) - return fail_fn(count); + if (likely(atomic_xchg(count, -1) != 1)) + return fail_fn(count); return 0; } |