Re: [RFC PATCH 2/2] macvtap: TX zero copy between guest and host kernel

Michael S. Tsirkin
2010-09-15T05:18:49Z

On Tue, Sep 14, 2010 at 12:36:23PM -0700, Shirley Ma wrote:
> On Tue, 2010-09-14 at 21:01 +0200, Michael S. Tsirkin wrote:
> > > > I think that you should be able to simply combine
> > > > the two drivers together, add an ioctl to
> > > > enable/disable zero copy mode of operation.
> > >
> > > That could work. But what's the purpose to have two drivers if one
> > > driver can handle it?
> > >
> > > Thanks
> > > Shirley
> >
> > This was just an idea: I thought it's a good way for people interested
> > in this zero copy thing to combine forces and avoid making
> > the same mistakes, but it's not a must of course.
>
> Ok, I will make a simple patch by reusing Xiaohui's some vhost code on
> handling vhost_add_used_and_signal() to see any performance changes.
>
> The interesting thing here when I run 32 instances netperf/netserver I
> didn't see any issue w/i this patch.
>
> Thanks
> Shirley

Yes, I agree this patch is useful for demo purposes:
simple, and shows what kind of performance gains
we can expect for TX.

--
MST