Hi Manit,
Can you identify which patch exactly within the series is causing the regression? We were not expecting performance to change with the patchset, but obviously something got missed.
I will follow up on our end to see if we see any regressions.
I must say, though, that 512 entries is pretty small rings sizes to use for 100G traffic. The slightest stall would cause those rings to overflow. What is perf like at other ring sizes, e.g. 1k or 2k?
/Bruce
> -----Original Message-----
> From: Honnappa Nagarahalli <Honnappa.Nagarahalli@arm.com>
> Sent: Thursday, July 3, 2025 8:03 AM
> To: Manit Mahajan <mmahajan@iol.unh.edu>
> Cc: Burakov, Anatoly <anatoly.burakov@intel.com>;
ci@dpdk.org; Richardson,
> Bruce <bruce.richardson@intel.com>; Wathsala Wathawana Vithanage
> <wathsala.vithanage@arm.com>; Paul Szczepanek
> <Paul.Szczepanek@arm.com>
> Subject: Re: Intel E810 Performance Regression - ARM Grace Server
>
> + Wathsala, Paul
>
> > On Jul 2, 2025, at 10:09 PM, Manit Mahajan <mmahajan@iol.unh.edu>
> wrote:
> >
> > Hi we have an update about the single core forwarding test on the ARM
> Grace server with the E810 100G Ice card. There was an intel PMDs series that
> was merged a week ago which had some performance failures when it was
> going through the CI:
>
https://patches.dpdk.org/project/dpdk/patch/01c94afcb0b1c2795c031afc8
>
72a8faf3f0db2b5.1749229651.git.anatoly.burakov@intel.com/
> >
> > and:
http://mails.dpdk.org/archives/test-report/2025-June/883654.html
> >
> > As you can see it causes roughly a 6% decrease in packets forwarded in the
> single core forwarding test with 64Byte frames and 512 txd/rxd. The delta
> tolerance on the single core forwarding test is 5%, so a 6% reduction in MPPS
> forwarded is a failure.
> >
> > This was merged into mainline 6 days ago, which is why some failures started
> to come in this week for the E810 Grace test.
> >
> > To double check this, on DPDK I checked out to:
> >
> > test/event: fix event vector adapter timeouts
> (2eca0f4cd5daf6cd54b8705f6f76f3003c923912) which directly precedes the
> Intel PMD patchseries, and ran the test and it forwarded the pre-regression
> MPPS that we expected.
> >
> > Then I checked out to net/intel: add common Tx mbuf recycle
> (f5fd081c86ae415515ab55cbacf10c9c50536ca1)
> >
> > and I ran the test and it had the 6% reduction in MPPS forwarded.
> >
> > Another thing to note is that regrettably the ARM Grace E810 test did not get
> run on the v7 (the final version) of this series, which meant the failure was not
> displayed on that version and that's probably why it was merged. We will look
> back into our job history and see why this test failed to report.
> >
> > Please let me know if you have any questions about the test, the testbed
> environment info, or anything else.
> Thanks Manit for looking into this. Adding few folks from Arm to follow up.
>
> >
> > Thanks,
> > Manit Mahajan
>
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