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

["Michael S. Tsirkin" <mst@redhat.com>]

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