My patch that removed the spin_lock calls from the tail of sys_semtimedop
introduced a bug:

Before my patch was merged, every operation that altered an array called
update_queue.  That call woke up threads that were waiting until a
semaphore value becomes 0.  I've accidentially removed that call.

The attached patch fixes that by modifying update_queue: the function now
loops internally and wakes up all threads.  The patch also removes
update_queue calls from the error path of sys_semtimedop: failed operations
do not modify the array, no need to rescan the list of waiting threads.
Signed-Off-By: Manfred Spraul <manfred@colorfullife.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>