Re: Virtio network performance poorer than emulated e1000

Balachandar
2010-07-24T15:04:45Z

On Fri, Jul 23, 2010 at 3:11 AM, Jes Sorensen <Jes.Sorensen@redhat.com> wrote:
> On 07/23/10 03:31, Balachandar wrote:
>> On Thu, Jul 22, 2010 at 8:18 PM, Sridhar Samudrala
>> I tried this one also but not much improvement. Actually i get a some
>> improvement if i disabled the tx timeout timer in the virtio_net.h in
>> qemu-kvm. I read that with vhost the data flow path differs from
>> normal operation. So is the timeout applicable when we  use vhost
>> also? Actually i dont see any improvement with vhost. I am just
>> wondering what am i missing? The thing that worries me is that
>> emulated nic offers much greater performance than virtio with vhost.
>> So i feel i am doing something wrong but unable to find it.
>
> Could you try measuring something meaningful instead of ping please?
> netperf or some other benchmark?
>
> Jes
>

Actually i got better results when i downloaded qemu-kvm 0.12.4 from
sourceforge and ran it. Now virtio performs better than emaulated
e1000 with our own simple ping-pong latency tests. Previously i used
Debian squeeze kvm package and i got poor results for virtio. I used
vhost-net as described by the kvm
website.http://www.linux-kvm.org/page/VhostNet. This also seem to have
the same problems i faced with Debian kvm package. How are you guyz
using vhost? Is there any other way to use vhost?

Thanks,
Bala