[dpdk-dev] Fwd: DPDK testpmd forwarding performace degradation

[Alexander Belyakov]

Hello,

On Mon, Jan 26, 2015 at 8:08 PM, Stephen Hemminger <
stephen at networkplumber.org> wrote:

> On Mon, 26 Jan 2015 13:17:48 +0300
> Alexander Belyakov <abelyako at gmail.com> wrote:
>
> > Hello,
> >
> > recently I have found a case of significant performance degradation for
> our
> > application (built on top of DPDK, of course). Surprisingly, similar
> issue
> > is easily reproduced with default testpmd.
> >
> > To show the case we need simple IPv4 UDP flood with variable UDP payload
> > size. Saying "packet length" below I mean: Eth header length (14 bytes) +
> > IPv4 header length (20 bytes) + UPD header length (8 bytes) + UDP payload
> > length (variable) + CRC (4 bytes). Source IP addresses and ports are
> selected
> > randomly for each packet.
> >
> > I have used DPDK with revisions 1.6.0r2 and 1.7.1. Both show the same
> issue.
> >
> > Follow "Quick start" guide (http://dpdk.org/doc/quick-start) to build
> and
> > run testpmd. Enable testpmd forwarding ("start" command).
> >
> > Table below shows measured forwarding performance depending on packet
> > length:
> >
> > No. -- UDP payload length (bytes) -- Packet length (bytes) -- Forwarding
> > performance (Mpps) -- Expected theoretical performance (Mpps)
>
> Did you try using git bisect to identify the problem.
>

I believe dpdk-1.6.0r2 is the first release with bypass adapter (device id
155d) support and it already has the issue. So it seems I have no "good"
point.

Alexander