Subject: Re: [PATCH/RFC 2.6.21 3/5] ehca: completion queue: remove use of do_mmap()

From: Roland Dreier <[email-masked]>
Date: Thu, 11 Jan 2007 11:56:18 -0800

> >  	spin_lock_irqsave(&ehca_cq_idr_lock, flags);
 > >  	while (my_cq->nr_callbacks)
 > >  		yield();

 > Isn't that code outright buggy?  Calling into the scheduler with a
 > spinlock held and local interrupts disabled...

Yes, absolutely -- if nr_callbacks is ever nonzero then this will
obviously crash instantly.

 - R.