Re: virtio: put last_used and last_avail index into ring itself.

2010-05-10 Thread Rusty Russell
On Sun, 9 May 2010 06:27:33 pm Michael S. Tsirkin wrote: > On Fri, May 07, 2010 at 12:35:39PM +0930, Rusty Russell wrote: > > Then there's padding to page boundary. That puts us on a cacheline again > > for the used ring; also 2 bytes per entry. > > > > Hmm, is used ring really 2 bytes per entry

Re: virtio: put last_used and last_avail index into ring itself.

2010-05-09 Thread Michael S. Tsirkin
On Fri, May 07, 2010 at 12:35:39PM +0930, Rusty Russell wrote: > On Thu, 6 May 2010 03:57:55 pm Michael S. Tsirkin wrote: > > On Thu, May 06, 2010 at 10:22:12AM +0930, Rusty Russell wrote: > > > On Wed, 5 May 2010 03:52:36 am Michael S. Tsirkin wrote: > > > > What do you think? > > > > > > I think

Re: virtio: put last_used and last_avail index into ring itself.

2010-05-06 Thread Rusty Russell
On Thu, 6 May 2010 03:57:55 pm Michael S. Tsirkin wrote: > On Thu, May 06, 2010 at 10:22:12AM +0930, Rusty Russell wrote: > > On Wed, 5 May 2010 03:52:36 am Michael S. Tsirkin wrote: > > > What do you think? > > > > I think everyone is settled on 128 byte cache lines for the forseeable > > future,

Re: virtio: put last_used and last_avail index into ring itself.

2010-05-05 Thread Michael S. Tsirkin
On Thu, May 06, 2010 at 10:22:12AM +0930, Rusty Russell wrote: > On Wed, 5 May 2010 03:52:36 am Michael S. Tsirkin wrote: > > > virtio: put last_used and last_avail index into ring itself. > > > > > > Generally, the other end of the virtio ring doesn't need

Re: virtio: put last_used and last_avail index into ring itself.

2010-05-05 Thread Rusty Russell
On Wed, 5 May 2010 03:52:36 am Michael S. Tsirkin wrote: > > virtio: put last_used and last_avail index into ring itself. > > > > Generally, the other end of the virtio ring doesn't need to see where > > you're up to in consuming the ring. However, to complet

Re: virtio: put last_used and last_avail index into ring itself.

2010-05-04 Thread Michael S. Tsirkin
> virtio: put last_used and last_avail index into ring itself. > > Generally, the other end of the virtio ring doesn't need to see where > you're up to in consuming the ring. However, to completely understand > what's going on from the outside, this information must

[PATCH 1/5] virtio: put last_used and last_avail index into ring itself.

2008-04-17 Thread Rusty Russell
Generally, the other end of the virtio ring doesn't need to see where you're up to in consuming the ring. However, in order for an external entity to understand it, it must be exposed. For example, if you want to save and restore a virtio_ring, but you're not the consumer because the kernel is us