Re: [Make-wifi-fast] Weird periodic latency

[Bob McMahon <bob.mcmahon@broadcom.com>]

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I think more current WiFi chips can do scanning without any impact to
traffic per having dedicated radios for off channel
estimates.  Also, it's good to know the width of the latency impacts along
with the delay values. Finally, fault isolation
could include a UDP send with the ack as shown here
<https://www.spinics.net/lists/netdev/msg176415.html>. We find ping
latencies, though a widely available tool, as insufficient
to qualify or diagnose latency.

Bob

On Sat, Jan 16, 2021 at 9:48 AM Dave Taht <dave.taht@gmail.com> wrote:

> That implies it is doing a channel scan. Dumb.
>
> https://blog.cerowrt.org/post/disabling_channel_scans/
>
> but what you encountered seemed more disabling than that, and the
> ath10k is supposed to be able to do background channel scans.
>
>
> On Sat, Jan 16, 2021 at 6:47 AM Michael Yartys
> <michael.yartys@protonmail.com> wrote:
> >
> > I'm pretty sure I've managed to figure out what causes the short sharp
> periodic latency spikes. The Gnome location service uses the surrounding
> wireless networks as one of the methods to determine your location. When
> it's turned on I get the following results:
> >
> > https://imgur.com/a/pNXuVRe
> >
> > When it's disabled the latency spikes are gone (and notice that AQL is
> working here as there is some background traffic from other clients):
> >
> > https://imgur.com/a/v4wWkAC
> >
> > Now, I wasn't able to reproduce the weird roller coaster like latency
> that I saw previously. I rebooted the laptop before I did these tests, so I
> guess that solved it.
> >
> > Michael
>
>
>
> --
> "For a successful technology, reality must take precedence over public
> relations, for Mother Nature cannot be fooled" - Richard Feynman
>
> dave@taht.net <Dave Täht> CTO, TekLibre, LLC Tel: 1-831-435-0729
>

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