From: Jamie Lokier <jamie@shareable.org>
One of the tests in unqueue_me() is redundant. If we acquire the spinlock,
the futex must be queued.
---
kernel/futex.c | 7 +++----
1 files changed, 3 insertions(+), 4 deletions(-)
diff -puN kernel/futex.c~futex-redundant-test kernel/futex.c
--- 25/kernel/futex.c~futex-redundant-test 2004-01-24 20:28:05.000000000 -0800
+++ 25-akpm/kernel/futex.c 2004-01-24 20:28:05.000000000 -0800
@@ -430,11 +430,10 @@ static int unqueue_me(struct futex_q *q)
spin_unlock(lock_ptr);
goto retry;
}
- if (likely(!list_empty(&q->list))) {
- list_del(&q->list);
- ret = 1;
- }
+ WARN_ON(list_empty(&q->list));
+ list_del(&q->list);
spin_unlock(lock_ptr);
+ ret = 1;
}
drop_key_refs(&q->key);
_