Re: [dpdk-dev] L3fwd mode in testpmd

[Kathleen Capella <Kathleen.Capella@arm.com>]

> -----Original Message-----
> From: Honnappa Nagarahalli <Honnappa.Nagarahalli@arm.com>
> Sent: Thursday, March 11, 2021 11:00 AM
> To: thomas@monjalon.net
> Cc: Jerin Jacob <jerinjacobk@gmail.com>; dev@dpdk.org; Kathleen Capella
> <Kathleen.Capella@arm.com>; Dharmik Thakkar
> <Dharmik.Thakkar@arm.com>; Ruifeng Wang <Ruifeng.Wang@arm.com>;
> david.marchand@redhat.com; Bruce Richardson
> <bruce.richardson@intel.com>; jerinj@marvell.com;
> hemant.agrawal@nxp.com; Ferruh Yigit <ferruh.yigit@intel.com>; Ananyev,
> Konstantin <konstantin.ananyev@intel.com>; Stephen Hemminger
> <sthemmin@microsoft.com>; nd <nd@arm.com>; nd <nd@arm.com>
> Subject: RE: [dpdk-dev] L3fwd mode in testpmd
> 
> <snip>
> 
> > >
> > > >
> > > > On Thu, Mar 11, 2021 at 12:01 AM Honnappa Nagarahalli
> > > > <Honnappa.Nagarahalli@arm.com> wrote:
> > > > >
> > > > > Hello,
> > > > >         Performance of L3fwd example application is one of the
> > > > > key
> > > > benchmarks in DPDK. However, the application does not have many
> > > > debugging statistics to understand the performance issues. We have
> > > > added L3fwd as another mode/stream to testpmd which provides
> > enough
> > > > statistics at various levels. This has allowed us to debug the
> > > > performance issues effectively.
> > > > >
> > > > > There is more work to be done to get it to upstreamable state. I
> > > > > am
> > > > wondering if such a patch is helpful for others and if the
> > > > community would be interested in taking a look. Please let me know
> what you think.
> > > >
> > > > We are using app/proc-info/ to attach and analyze the performance.
> > > > That helps to analyze the unmodified application. I think, if
> > > > something is missing in proc-info app, in my opinion it is better
> > > > to enhance proc-info so that it can help other third-party applications.
> > > >
> > > > Just my 2c.
> > > Thanks Jerin. We will explore that.
> >
> > I agree it is dangerous to rely too much on testpmd for everything.
> > Please tell us what in testpmd could be useful out of it.
> >
> Things that are very helpful in testpmd are: 1) HW statistics from the NIC 2)
> Forwarding stats 3) Burst stats (indication of headroom availability) 4) Easy to
> set parameters like RX and TX queue depths (among others) without having
> to recompile.

[Kathleen Capella] 
Thank you for the suggestion of app/proc-info. I've tried it out with 
l3fwd and see that it does have the HW stats from the NIC and the forwarding stats.
However, it does not have the burst stats testpmd offers, nor the 
ability to easily change parameters without having to recompile, 
which helps reduce debugging time significantly.