On Wed, Nov 02, 2011 at 01:49:36PM +1030, Rusty Russell wrote: > I thought it was still a WIP? The whole series - yes. This patch (and the serial number rewrite): no - these are pretty much rock solid. > Since the problem is contention on the lock inside the block layer, the > simplest solution is to have a separate lock to protect the virtqueue. As long as we still use a ->request_fn based driver that is not going to buy us anything, in fact it's going to make things worse. ->request_fn based drivers always have the queue lock held over the invocation of ->request_fn anyway, and then need it around the call to __blk_end_request_all. So you might minimally reduce contention time, but skyrocket the number of lock acquisations when separating them without changes to the block layer. With the ->make_request_fn based driver vlkb->lock does't protect anything but the virtuequeue anyway, but not having to take it over the wakeup there is a) done easily and b) neatly fits the model. -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
