On Wed, May 18, 2011 at 09:49:42AM +0930, Rusty Russell wrote: > On Tue, 17 May 2011 09:10:31 +0300, "Michael S. Tsirkin" <mst@xxxxxxxxxx> wrote: > > Well one can imagine a driver doing: > > > > while (virtqueue_get_buf()) { > > virtqueue_add_buf() > > } > > virtqueue_kick() > > > > which looks sensible (batch kicks) but might > > process any number of bufs between kicks. > > No, we currently only expose the buffers in the kick, so it can only > fill the ring doing that. > > We could change that (and maybe that's worth looking at)... Yes, I think we should - this way host and guest can process data in parallel without a kick. My patchset included that simply because it's one index less to be confused about. > > If we look at drivers closely enough, I think none > > of them do the equivalent of the above, but not 100% sure. > > I'm pretty sure we don't have this kind of 'echo' driver yet. Drivers > tend to take OS requests and queue them. The only one which does > anything even partially sophisticated is the net driver... > > Thanks, > Rusty. -- To unsubscribe from this list: send the line "unsubscribe linux-s390" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html