Re: [PATCH] virtio: Use ioeventfd for virtqueue notify

Michael S. Tsirkin
2010-10-03T14:34:39Z

On Sun, Oct 03, 2010 at 04:21:57PM +0200, Avi Kivity wrote:
> On 10/03/2010 03:51 PM, Michael S. Tsirkin wrote:
> >On Sun, Oct 03, 2010 at 01:01:59PM +0200, Avi Kivity wrote:
> >> >
> >> >Guest to Host TCP_STREAM throughput(Mb/sec)
> >> >-------------------------------------------
> >> >Msg Size vhost-net virtio-net virtio-net/ioeventfd
> >> >65536 12755 6430 7590
> >> >16384 8499 3084 5764
> >> > 4096 4723 1578 3659
> >> > 1024 1827 981 2060
> >>
> >> Even more impressive (expected since the copying, which isn't
> >> present for block, is now shunted off into an iothread).
> >>
> >> On the last test you even exceeded vhost-net. Any theories how/why?
> >>
> >> Again, efficiency numbers would be interesting.
> >>
> >> >Host to Guest TCP_STREAM throughput(Mb/sec)
> >> >-------------------------------------------
> >> >Msg Size vhost-net virtio-net virtio-net/ioeventfd
> >> >65536 11156 5790 5853
> >> >16384 10787 5575 5691
> >> > 4096 10452 5556 4277
> >> > 1024 4437 3671 5277
> >>
> >> Here you exceed vhost-net, too.
> >
> >This is with small packets- I suspect this is the extra
> >per interrupt overhead that eventfd has.
>
> This is using eventfd as well.

Sorry, I meant irqfd.

> --
> error compiling committee.c: too many arguments to function