[ovs-discuss] OVS DPDK performance for TCP traffic versus UDP

[Onkar Pednekar]

Hi Tiago,

Thanks for your reply.

Below are the answers to your questions in-line.


On Thu, Oct 4, 2018 at 4:07 AM Lam, Tiago <tiago.lam at intel.com> wrote:

> Hi Onkar,
>
> Thanks for your email. Your setup isn't very clear to me, so a few
> queries in-line.
>
> On 04/10/2018 06:06, Onkar Pednekar wrote:
> > Hi,
> >
> > I have been experimenting with OVS DPDK on 1G interfaces. The system has
> > 8 cores (hyperthreading enabled) mix of dpdk and non-dpdk capable ports,
> > but the data traffic runs only on dpdk ports.
> >
> > DPDK ports are backed by vhost user netdev and I have configured the
> > system so that hugepages are enabled, CPU cores isolated with PMD
> > threads allocated to them and also pinning the VCPUs.>
> > When I run UDP traffic, I see ~ 1G throughput on dpdk interfaces with <
> > 1% packet loss. However, with tcp traffic, I see around 300Mbps
> > thoughput. I see that setting generic receive offload to off helps, but
> > still the TCP thpt is very less compared to the nic capabilities. I know
> > that there will be some performance degradation for TCP as against UDP
> > but this is way below expected.
> >
>
> When transmitting traffic between the DPDK ports, what are the flows you
> have setup? Does it follow a p2p or pvp setup? In other words, does the
> traffic flow between the VM and the physical ports, or only between
> physical ports?
>

 The traffic is between the VM and the physical ports.


> > I don't see any packets dropped for tcp on the internal VM (virtual)
> > interfaces.
> >
> > I would like to know if there is an settings (offloads) for the
> > interfaces or any other config I might be missing.
>
> What is the MTU set on the DPDK ports? Both physical and vhost-user?
>
> $ ovs-vsctl get Interface [dpdk0|vhostuserclient0] mtu
>

MTU set on physical ports = 2000
MTU set on vhostuser ports = 1500


> This will help to clarify some doubts around your setup first.
>
> Tiago.
>
> >
> > Thanks,
> > Onkar
> >
> >
> > _______________________________________________
> > discuss mailing list
> > discuss at openvswitch.org
> > https://mail.openvswitch.org/mailman/listinfo/ovs-discuss
> >
>
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