Re: [PATCH iwl-net] idpf: decrease statistics refresh interval

[Tantilov, Emil S]

On 6/12/2026 2:29 AM, Alexander Lobakin wrote:
> From: Danny Gonzalez <digonzal@xxxxxxxxxx>
> Date: Thu, 11 Jun 2026 11:26:18 -0700
>
> > On Thu, Jun 11, 2026 at 8:57 AM Alexander Lobakin
> > <aleksander.lobakin@xxxxxxxxx> wrote:
> > > From: Danny Gonzalez <digonzal@xxxxxxxxxx>
> > > Date: Thu, 11 Jun 2026 00:24:37 +0000
> > >
> > > > The default 10s statistics refresh interval is too slow for real-time
> > > > monitoring and causes network selftests (e.g., uso.py) to fail when
> > > > verifying traffic immediately after transmission.
> > > >
> > > > A 10s delay also causes aliasing in telemetry tools polling at shorter
> > > > intervals (e.g., 5s), leading to inaccurate rate calculations on
> > > > high-throughput NICs.
> > > >
> > > > Decrease the refresh interval to 250ms to ensure fresh stats and fix
> > > > test failures.
> > >
> > > Have you tried a bit more conservate value like 1s? Wouldn't it be
> > > enough for tests to pass?
> > >
> > > 250 ms is also okay, just curious.
> >
> > Yes, 1s also allows the tests to pass.
> >
> > We have a preference for 250 ms since High-Freq Telemetry (1s poll)
> > 1s driver refresh rate causes aliasing:
> >
> > # sar -n DEV 1 | grep eth1
> > 10:52:15         eth1    390.00    339.00     51.92     55.54
> > 0.00      0.00      0.00      0.00
> > 10:52:16         eth1    409.00    360.00     54.72     58.64
> > 0.00      0.00      0.00      0.00
> > 10:52:17         eth1      0.00      0.00      0.00      0.00
> > 0.00      0.00      0.00      0.00
>
> Ack!
>
> Reviewed-by: Alexander Lobakin <aleksander.lobakin@xxxxxxxxx>
>
> > Thanks,
> > Danny
>
> Thanks,
> Olek

Unfortunately this doesn't scale very well as it introduces a bit of an 
overhead for the virtchnl having to update stats at a higher frequency, 
which is why the delay was so big to begin with ... You can have 
multiple vports and thousands of VFs. We do have a different solution 
for this case in the OOT driver, where we only speed it up a bit when 
there is an actual request from the user via mod_delayed_work():
https://github.com/intel/ethernet-linux-idpf/blob/main/idpf/src/idpf_ethtool.c#L1735

which would be a better approach for this issue, IMHO.

Thanks,
Emil