On Wed, 2 Nov 2011 03:25:44 -0400, Christoph Hellwig <hch@xxxxxxxxxxxxx> wrote: > 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. OK, thanks. > > 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. Of course... > 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. It adds YA API though. But I can't better it. Doing the "should we kick" check outside the lock is problematic, and doing it inside every add() is inefficient. So let's change the API for everyone, into: bool virtqueue_should_kick(struct virtqueue *vq); void virtqueue_kick(struct virtqueue *vq); Patch series coming... Thanks, Rusty. -- 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