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

[Onkar Pednekar]

Hi Tiago,

Sure. I'll try that.

Thanks,
Onkar

On Fri, Oct 5, 2018 at 9:06 AM Lam, Tiago <tiago.lam at intel.com> wrote:

> Hi Onkar,
>
> Thanks for shedding some light.
>
> I don't think your difference in performance will have to do your
> OvS-DPDK setup. If you're taking the measurements directly from the
> iperf server side you'd be going through the "Internet". Assuming you
> don't have a dedicated connection there, things like your connection's
> bandwidth, the RTT from end to end start to matter considerably,
> specially for TCP.
>
> To get to the bottom of it I'd advise you to take the iperf server and
> connect it directly to the first machine (Machine 1). You would be
> excluding any "Internet" interference and be able to get the performance
> of a pvp scenario first.
>
> Assuming you're using kernel forwarding inside the VMs, if you want to
> squeeze in the extra performance it is probably wise to use DPDK testpmd
> to forward the traffic inside of the VMs as well, as explained here:
> http://docs.openvswitch.org/en/latest/howto/dpdk/#phy-vm-phy-vhost-loopback
>
> Regards,
> Tiago.
>
> On 04/10/2018 21:06, Onkar Pednekar wrote:
> > 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
> > <mailto: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 <mailto:discuss at openvswitch.org>
> >     > https://mail.openvswitch.org/mailman/listinfo/ovs-discuss
> >     >
> >
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.openvswitch.org/pipermail/ovs-discuss/attachments/20181005/c674aee2/attachment.html>