Wrongly wakened pthread_cond_wait() on 2.4.18 : futex.c?

Patching stock 2.4.18 with patch-kngpt-2.4.18-2.0.3-2 downloaded from
http://www-124.ibm.com/pthreads/download/stable/kernel/, I run Dr. Uwe's
producer/consumer case against ngpt-2.0.4 on a SMP box and found it's 
trapped in endless loop.

According to the printed info, I noticed that either producer or consumer
will
be hooked to endlessly wakened pthread_cond_wait() and prevent other 
threads from grabbing the shared mutex.  Because it is using 
PROCESS_SHARED condition variable, I traced back to the futex lines 
and found a possible reason.

Within futex_poll() of kernel/futex.c, line 246,247 read
	if (!list_empty(&q->list))
		ret = POLLIN | POLLRDNORM;
which means the select() on futex_fd will return right away.

Changing to
	if (list_empty(&q->list))
		ret = POLLIN | POLLRDNORM;
and recompile the kernel, the issue will be gone.

Please correct me if I misunderstood the functions.

----------------------------------------------------------
Bingwei Liu
My words stand for personal point of view