blk_get_queue() is easy to 'fix', it grabs io_request_lock for no good
reason at all. I think this must have been a failed attempt to protect
switching of queues, however it's obviously very broken in this regard.
So in fact no skin is off our nose for just removing the io_request_lock
in that path. 2.5 will have it properly reference counted...
> And your lock profile certainly shows the io_request_lock as a _major_
> lock user, although I'm happy to see that contention seems to be
> reasonably low. Still, I'd bet that it is worth working on..
Sure is, the bio patches have not had io_request_lock in them for some
time.
-- Jens Axboe- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/