Re: [dpdk-dev] random pkt generator PMD

[Arnon Warshavsky <arnon@qwilt.com>]

On Wed, Jun 15, 2016 at 4:03 PM, Dumitrescu, Cristian <
cristian.dumitrescu@intel.com> wrote:

>
>
> > -----Original Message-----
> > From: Yerden Zhumabekov [mailto:e_zhumabekov@sts.kz]
> > Sent: Wednesday, June 15, 2016 1:55 PM
> > To: Dumitrescu, Cristian <cristian.dumitrescu@intel.com>; Panu
> Matilainen
> > <pmatilai@redhat.com>; dev@dpdk.org
> > Subject: Re: [dpdk-dev] random pkt generator PMD
> >
> >
> >
> > On 15.06.2016 18:25, Dumitrescu, Cristian wrote:
> >
> > >>>> So add a loop-mode to pcap pmd?
> > >>> It would be nice to have an option like "...,rewind=1,...".
> > >> As Cristian points out in
> > >> http://dpdk.org/ml/archives/dev/2016-June/041589.html, the current
> > pmd
> > >> behavior of stopping is the odd man out in the pmd crowd.
> > >>
> > >> Rather than whether to rewind or not, I'd make the number of loops
> > >> configurable, defaulting to forever and 1 being the equal to current
> > >> behavior.
> > >>
> > >>    - Panu -
> > > +1
> >
> > I'm afraid, all packets from pcap file would need to be preloaded to
> > memory. Otherwise, each loop would infer pcap_open/pcap_close(), am I
> > wrong?
>
> This exactly what the code in source port is doing.
>
> Basically, this is optimized for the case when number of packets in the
> PCAP file is relatively small, so the PCAP memory footprint when loaded
> into memory is small so it fits the L1/L2 cache. Provides traffic
> generation capability when performance measurements are not key: testing,
> code development on your laptop while on board of a plane, simulation
> environments, etc.
>
> When the PCAP is large (e.g. capture of the traffic in your local cloud
> for 2 mins), then PCAP memory gets swapped to disk and performance
> obviously drops. Still better than opening PCAC for each packet. Useful for
> e.g. IDS/IPS testing.
>


If you are after continuous traffic that varies all the time in high
performance rather than loop the same pcap over and over again,
check out  the T-Rex traffic generator which is an open source and dpdk
based.
https://trex-tgn.cisco.com/

/Arnon