# Re: \[PATCH\] macvtap: Fix macvtap\_get\_queue to use rxhash first

- From: Michael S. Tsirkin \<mst@redhat.com\>
- Date: 2011-12-07 16:10:02 
- List: netdev
- Page: https://ratatoskr.run/netdev/2011/12/10884478
- Thread: https://ratatoskr.run/netdev/2011/11/10883220/t.md

```text
On Fri, Nov 25, 2011 at 01:35:52AM -0500, David Miller wrote:
> From: Krishna Kumar2 <redacted>
> Date: Fri, 25 Nov 2011 09:39:11 +0530
> 
> > Jason Wang [ref] wrote on 11/25/2011 08:51:57 AM:
> >>
> >> My description is not clear again :(
> >> I mean the same vhost thead:
> >>
> >> vhost thread #0 transmits packets of flow A on processor M
> >> ...
> >> vhost thread #0 move to another process N and start to transmit packets
> >> of flow A
> > 
> > Thanks for clarifying. Yes, binding vhosts to CPU's
> > makes the incoming packet go to the same vhost each
> > time. BTW, are you doing any binding and/or irqbalance
> > when you run your tests? I am not running either at
> > this time, but thought both might be useful.
> 
> So are we going with this patch or are we saying that vhost binding
> is a requirement?

OK we didn't come to a conclusion so I would be inclined
to merge this patch as is for 3.2, and revisit later.
One question though: do these changes affect userspace
in any way? For example, will this commit us to
ensure that a single flow gets a unique hash even
for strange configurations that transmit the same flow
from multiple cpus?

-- 
MST
```