Subject: Re: [v3 RFC PATCH 0/4] Implement multiqueue virtio-net

From: "Michael S. Tsirkin" <[email-masked]>
Date: Wed, 3 Nov 2010 09:01:16 +0200

On Thu, Oct 28, 2010 at 12:48:57PM +0530, Krishna Kumar2 wrote:
> > Krishna Kumar2/India/IBM wrote on 10/28/2010 10:44:14 AM:
> >
> > > > > > Results for UDP BW tests (unidirectional, sum across
> > > > > > 3 iterations, each iteration of 45 seconds, default
> > > > > > netperf, vhosts bound to cpus 0-3; no other tuning):
> > > > >
> > > > > Is binding vhost threads to CPUs really required?
> > > > > What happens if we let the scheduler do its job?
> > > >
> > > > Nothing drastic, I remember BW% and SD% both improved a
> > > > bit as a result of binding.
> > >
> > > If there's a significant improvement this would mean that
> > > we need to rethink the vhost-net interaction with the scheduler.
> >
> > I will get a test run with and without binding and post the
> > results later today.
> 
> Correction: The result with binding is is much better for
> SD/CPU compared to without-binding:

Something that was suggested to me off-list is
trying to set smp affinity for NIC: in host to guest
case probably virtio-net, for external to guest
the host NIC as well.

-- 
MST