Re: [dpdk-dev] [dpdk-virtio] Performance tuning for dpdk with virtio?

[Clarylin L <clearasu@gmail.com>]

My VM has two ports connecting to two linux bridges (in turn connecting two
physical ports). DPDK is used to forward between these two ports (one port
connected to traffic generator and the other connected to sink). I used
iperf to test the throughput between the traffic generator and one port on
VM, as well as throughput between the other port and the sink. Both legs
show around 7.5G throughput.

Traffic anyway would goes through bridge to reach to the VM ports, so I
think linux bridge does support much higher throughput, doesn't it?

On Fri, Jul 17, 2015 at 2:20 PM, Stephen Hemminger <
stephen@networkplumber.org> wrote:

> On Fri, 17 Jul 2015 11:03:15 -0700
> Clarylin L <clearasu@gmail.com> wrote:
>
> > I am running dpdk with a virtual guest as a L2 forwarder.
> >
> > If the virtual guest is on passthrough, dpdk can achieve around 10G
> > throughput. However if the virtual guest is on virtio, dpdk achieves just
> > 150M throughput, which is a huge degrade. Any idea what could be the
> cause
> > of such poor performance on virtio? and any performance tuning
> techniques I
> > could try? Thanks a lot!
>
> The default Linux bridge (and OVS) switch are your bottleneck.
> It is not DPDK virtio issue in general. There are some small performance
> gains still possible with virtio enhancements (like offloading).
>
> Did you try running OVS-DPDK on the host?
>