diff options
Diffstat (limited to 'include/asm-generic/mutex-xchg.h')
| -rw-r--r-- | include/asm-generic/mutex-xchg.h | 19 |
1 files changed, 12 insertions, 7 deletions
diff --git a/include/asm-generic/mutex-xchg.h b/include/asm-generic/mutex-xchg.h index 580a6d35c70..f169ec06478 100644 --- a/include/asm-generic/mutex-xchg.h +++ b/include/asm-generic/mutex-xchg.h @@ -26,24 +26,29 @@ 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); } /** * __mutex_fastpath_lock_retval - try to take the lock by moving the count * from 1 to a 0 value * @count: pointer of type atomic_t - * @fail_fn: function to call if the original value was not 1 * - * Change the count from 1 to a value lower than 1, and call <fail_fn> if it - * wasn't 1 originally. This function returns 0 if the fastpath succeeds, - * or anything the slow path function returns + * Change the count from 1 to a value lower than 1. This function returns 0 + * if the fastpath succeeds, or -1 otherwise. */ static inline int -__mutex_fastpath_lock_retval(atomic_t *count, int (*fail_fn)(atomic_t *)) +__mutex_fastpath_lock_retval(atomic_t *count) { if (unlikely(atomic_xchg(count, 0) != 1)) - return fail_fn(count); + if (likely(atomic_xchg(count, -1) != 1)) + return -1; return 0; } |