[dpdk-dev] Performance issue with vmxnet3 pmd

[Hyunseok]

Thanks for your response.

I am actually more interested in stock (non-dpdk) vmxnet3 driver vs.
vmxnet3 pmd driver comparison.

When I forward pkts from stock vmxnet3 driver, I am able to achieve much
higher throughput than with vmxnet3 pmd.  To make comparison fair, I did
not leverage gro/gso.

Does any of the overheads you mentioned play a role in this comparison?
Here I am comparing different drivers for the same vmxnet3 interface...

Regards,
Hyunseok
On Jul 7, 2014 7:03 PM, "Patel, Rashmin N" <rashmin.n.patel at intel.com>
wrote:

> Hi Hyunseok,
>
> We should not compare Vmxnet3-PMD with ixgbe-PMD performance as Vmxnet3
> device is a para-virtual device and it's not similar to directly assigned
> device to a VM either.
> There is VMEXIT/VMEXIT occurrence at burst-size boundary and that overhead
> can’t be eliminated unless the design of Vmxnet3 is updated in future. In
> addition to that the packets is being touched in ESXi hypervisor vSwitch
> layer between physical NIC and a virtual machine, which introduces extra
> overhead, which you won't have in case of using Niantic being used natively
> or passed through Vt-d to a virtual machine.
>
> Feature wise, we can compare it to Virtio-PMD solution, but again there is
> a little different in device handling and backend driver support compared
> to Vmxnet3 device so performance comparison won’t to apple to apple.
>
> Thanks,
> Rashmin
>
> -----Original Message-----
> From: dev [mailto:dev-bounces at dpdk.org] On Behalf Of Hyunseok
> Sent: Monday, July 07, 2014 3:22 PM
> To: dev at dpdk.org
> Subject: [dpdk-dev] Performance issue with vmxnet3 pmd
>
> Hi,
>
> I was testing l2-fwd with vmxnet3 pmd (included in dpdk).
>
> The maximum forwarding rate I got from vmxnet3 pmd with l2fwd is only 2.5
> to 2.8 Gbps.
>
> This is in contrast with ixgbe pmd with which I could easily achieve 10
> gbps forwarding rate.
>
> With the original vmxnet3 driver (non pmd), I could also achieve close to
> 10 gpbs with multiple iperf.   But I can never achieve that rate with
> vmxnet3 pmd...
>
> So basically vmxnet3 pmd doesn't seem that fast.  Is this a known issue?
>
> Thanks,
> -Hyunseok
>