Re: L3 Forwarding performance of DPDK on virtio

["Tan, Jianfeng" <jianfeng.tan@intel.com>]

Hello!

On 1/21/2016 7:51 AM, Clarylin L wrote:
> I am running dpdk within a virtual guest as a L3 forwarder.
>
>
> The 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.
>
>
> If the VM/DPDK is running on passthrough, it can achieve around 10G
> end-to-end (from traffic generator to sink) throughput. However if the
> VM/DPDK is running on virtio (virtio-net-pmd), it achieves just 150M
> throughput, which is a huge degrade.
>
>
> On the virtio, I also measured the throughput between the traffic generator
> and its connected port on VM, as well as throughput between the sink and
> it's VM port. Both legs show around 7.5G throughput. So I guess forwarding
> within the VM (from one port to the other) would be a big killer of the
> performance.
>
>
> Any suggestion on how I can root cause the poor performance issue, or any
> idea on performance tuning techniques for virtio? thanks a lot!

The L3 forwarder, you mentioned, is the l3fwd example in DPDK? If so, I 
doubt it can work well with virtio, see another thread "Add API to get 
packet type info".

Thanks,
Jianfeng