Re: Incorrect circular locking dependency?

[David Howells <dhowells@redhat.com>]

Peter Zijlstra <peterz@infradead.org> wrote:

> Creating a new class for your second workqueue might help,

I only have one workqueue.  The problem is there are two waitqueues, but
init_waitqueue_head() always sets q->lock to the same class.

> we'd have to pass a second key through __create_workqueue_key() and pass
> that into init_cpu_workqueue() and apply it to cwq->lock using
> lockdep_set_class() and co.

Actually, wouldn't just making init_cpu_workqueue() apply a class to
cwq->more_work that's common to all workqueues suffice?  Or even, have
init_waitqueue_head() apply an alternate class to q->lock?

David