__mutex_fastpath_lock(atomic_t *count, void (*fail_fn)(atomic_t *))
{
if (unlikely(atomic_xchg(count, 0) != 1))
- fail_fn(count);
- else
- smp_mb();
+ /*
+ * 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(atomic_t *count, int (*fail_fn)(atomic_t *))
{
if (unlikely(atomic_xchg(count, 0) != 1))
- return fail_fn(count);
- else {
- smp_mb();
- return 0;
- }
+ if (likely(atomic_xchg(count, -1) != 1))
+ return fail_fn(count);
+ return 0;
}
/**
static inline void
__mutex_fastpath_unlock(atomic_t *count, void (*fail_fn)(atomic_t *))
{
- smp_mb();
if (unlikely(atomic_xchg(count, 1) != 0))
fail_fn(count);
}
if (prev < 0)
prev = 0;
}
- smp_mb();
return prev;
}