[Make-wifi-fast] Weird periodic latency

[Make-wifi-fast] Weird periodic latency

[Michael Yartys]

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Hi

I decided to run a couple of flent 8-stream TCP downloads from netperf-eu.bufferbloat.net to my Fedora 33 laptop, and I noticed some weird periodic latency in the resulting graphs. My router is the NETGEAR R7800 running OpenWrt with an ath10k radio. Here's a graph that's representative of the results that I got: https://imgur.com/a/BOKNzht

This looks similar to the latency spikes you would get from channel scans, but I have specified the BSSID in the Gnome network settings, which means that background scanning should be disabled. In addition, the test ran for 30 minutes, and channel scans are much more frequent than the latency spikes seen in the graph above. Here's what channel scans look like in a 15 minute long test: https://imgur.com/a/YJepfcp

Does anyone here know what could be causing this behaviour?

Michael

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

[Toke Høiland-Jørgensen]

Michael Yartys via Make-wifi-fast <make-wifi-fast@lists.bufferbloat.net>
writes:

> Hi
>
> I decided to run a couple of flent 8-stream TCP downloads from
> netperf-eu.bufferbloat.net to my Fedora 33 laptop, and I noticed some
> weird periodic latency in the resulting graphs. My router is the
> NETGEAR R7800 running OpenWrt with an ath10k radio. Here's a graph
> that's representative of the results that I got:
> https://imgur.com/a/BOKNzht
>
> This looks similar to the latency spikes you would get from channel
> scans, but I have specified the BSSID in the Gnome network settings,
> which means that background scanning should be disabled. In addition,
> the test ran for 30 minutes, and channel scans are much more frequent
> than the latency spikes seen in the graph above. Here's what channel
> scans look like in a 15 minute long test: https://imgur.com/a/YJepfcp
>
> Does anyone here know what could be causing this behaviour?

Hmm, your email reminds me that the server you are testing against was
having some issue before the holidays. So it may just be that it's
crapping out and it has nothing to do with your connection.

You could try adding a secondary ping flow (--test-parameter
ping_hosts=one.one.one.one should do it) and see if that secondary flow
also shows the same spikes. If it does, it's likely your connection, if
not it's likely the server...

-Toke

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

[Michael Yartys]

I assume that I got it right by running:

flent --test-parameter ping_hosts=1.1.1.1 -l 300 netperf-eu.bufferbloat.net tcp_8down

Either way, I think I'll have to do this test at another time since someone is streaming TV downstairs (via Ethernet!) and it really pollutes the results: https://imgur.com/a/F33LjeA

For what it's worth, the ping to 1.1.1.1 looks the same.

Michael

‐‐‐‐‐‐‐ Original Message ‐‐‐‐‐‐‐

On Friday, January 15th, 2021 at 17:23, Toke Høiland-Jørgensen <toke@toke.dk> wrote:

> Michael Yartys via Make-wifi-fast make-wifi-fast@lists.bufferbloat.net
>
> writes:
>
> > Hi
> >
> > I decided to run a couple of flent 8-stream TCP downloads from
> >
> > netperf-eu.bufferbloat.net to my Fedora 33 laptop, and I noticed some
> >
> > weird periodic latency in the resulting graphs. My router is the
> >
> > NETGEAR R7800 running OpenWrt with an ath10k radio. Here's a graph
> >
> > that's representative of the results that I got:
> >
> > https://imgur.com/a/BOKNzht
> >
> > This looks similar to the latency spikes you would get from channel
> >
> > scans, but I have specified the BSSID in the Gnome network settings,
> >
> > which means that background scanning should be disabled. In addition,
> >
> > the test ran for 30 minutes, and channel scans are much more frequent
> >
> > than the latency spikes seen in the graph above. Here's what channel
> >
> > scans look like in a 15 minute long test: https://imgur.com/a/YJepfcp
> >
> > Does anyone here know what could be causing this behaviour?
>
> Hmm, your email reminds me that the server you are testing against was
>
> having some issue before the holidays. So it may just be that it's
>
> crapping out and it has nothing to do with your connection.
>
> You could try adding a secondary ping flow (--test-parameter
>
> ping_hosts=one.one.one.one should do it) and see if that secondary flow
>
> also shows the same spikes. If it does, it's likely your connection, if
>
> not it's likely the server...
>
> -Toke

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

[Toke Høiland-Jørgensen]

Michael Yartys <michael.yartys@protonmail.com> writes:

> I assume that I got it right by running:
>
> flent --test-parameter ping_hosts=1.1.1.1 -l 300 netperf-eu.bufferbloat.net tcp_8down
>
> Either way, I think I'll have to do this test at another time since
> someone is streaming TV downstairs (via Ethernet!) and it really
> pollutes the results: https://imgur.com/a/F33LjeA
>
> For what it's worth, the ping to 1.1.1.1 looks the same.

The extra ping flow is not shown by default on the plot with the regular
ping (for that test), so you'll have to use '-p ping_extra' to see it...

-Toke

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

[Michael Yartys]

On Friday, January 15th, 2021 at 19:55, Toke Høiland-Jørgensen <toke@toke.dk> wrote:

> Michael Yartys michael.yartys@protonmail.com writes:
>
> > I assume that I got it right by running:
> >
> > flent --test-parameter ping_hosts=1.1.1.1 -l 300 netperf-eu.bufferbloat.net tcp_8down
> >
> > Either way, I think I'll have to do this test at another time since
> >
> > someone is streaming TV downstairs (via Ethernet!) and it really
> >
> > pollutes the results: https://imgur.com/a/F33LjeA
> >
> > For what it's worth, the ping to 1.1.1.1 looks the same.
>
> The extra ping flow is not shown by default on the plot with the regular
>
> ping (for that test), so you'll have to use '-p ping_extra' to see it...

Thanks for the tip! I use the GUI so I just selected ping_extra under the plot selector to confirm that they looked similar.
>
> -Toke

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

[Toke Høiland-Jørgensen]

Michael Yartys <michael.yartys@protonmail.com> writes:

> On Friday, January 15th, 2021 at 19:55, Toke Høiland-Jørgensen <toke@toke.dk> wrote:
>
>> Michael Yartys michael.yartys@protonmail.com writes:
>> 
>
>> > I assume that I got it right by running:
>> > 
>
>> > flent --test-parameter ping_hosts=1.1.1.1 -l 300 netperf-eu.bufferbloat.net tcp_8down
>> > 
>
>> > Either way, I think I'll have to do this test at another time since
>> > 
>
>> > someone is streaming TV downstairs (via Ethernet!) and it really
>> > 
>
>> > pollutes the results: https://imgur.com/a/F33LjeA
>> > 
>
>> > For what it's worth, the ping to 1.1.1.1 looks the same.
>> 
>
>> The extra ping flow is not shown by default on the plot with the regular
>> 
>
>> ping (for that test), so you'll have to use '-p ping_extra' to see it...
>
> Thanks for the tip! I use the GUI so I just selected ping_extra under
> the plot selector to confirm that they looked similar.

Ah, right, I see! OK, in that case it's likely actually something on
your networking causing those spikes... Hmm, if this is WiFi I guess it
could be periodic interference of some kind? A misbehaving device that's
blasting out RF at some interval?

-Toke

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

[Dave Taht]

oops meant to cc the list

On Fri, Jan 15, 2021 at 11:09 AM Dave Taht <dave.taht@gmail.com> wrote:
>
> On Fri, Jan 15, 2021 at 9:00 AM Michael Yartys via Make-wifi-fast
> <make-wifi-fast@lists.bufferbloat.net> wrote:
> >
> > I assume that I got it right by running:
> >
> > flent --test-parameter ping_hosts=1.1.1.1 -l 300 netperf-eu.bufferbloat.net tcp_8down
> >
> > Either way, I think I'll have to do this test at another time since someone is streaming TV downstairs (via Ethernet!) and it really pollutes the results: https://imgur.com/a/F33LjeA
>
> I wouldn't say that pollutes the results, I'd say those are the
> typical and terrible results most users get when trying to do more
> than one thing at once on wifi or over the internet. Also it helps to
> have sqm on your isp updownlink, especially with netflix as it is
> bursty as heck
>
> I do not know if aql is enabled on that chipset.  To my eye, it isn't,
> but the induced latency isn't quite high enough to represent what I
> viewed as the baseline problems.
>
> https://forum.openwrt.org/t/aql-and-the-ath10k-is-lovely/59002
>
> Do a packet capture at the AP and look for multciast bursts especially
>
> And I keep trying to set aside time to go deep on AQL again, as the
> 7800 is a pretty popular box...
>
>
>
> >
> > For what it's worth, the ping to 1.1.1.1 looks the same.
> >
> > Michael
> >
> > ‐‐‐‐‐‐‐ Original Message ‐‐‐‐‐‐‐
> >
> > On Friday, January 15th, 2021 at 17:23, Toke Høiland-Jørgensen <toke@toke.dk> wrote:
> >
> > > Michael Yartys via Make-wifi-fast make-wifi-fast@lists.bufferbloat.net
> > >
> > > writes:
> > >
> > > > Hi
> > > >
> > > > I decided to run a couple of flent 8-stream TCP downloads from
> > > >
> > > > netperf-eu.bufferbloat.net to my Fedora 33 laptop, and I noticed some
> > > >
> > > > weird periodic latency in the resulting graphs. My router is the
> > > >
> > > > NETGEAR R7800 running OpenWrt with an ath10k radio. Here's a graph
> > > >
> > > > that's representative of the results that I got:
> > > >
> > > > https://imgur.com/a/BOKNzht
> > > >
> > > > This looks similar to the latency spikes you would get from channel
> > > >
> > > > scans, but I have specified the BSSID in the Gnome network settings,
> > > >
> > > > which means that background scanning should be disabled. In addition,
> > > >
> > > > the test ran for 30 minutes, and channel scans are much more frequent
> > > >
> > > > than the latency spikes seen in the graph above. Here's what channel
> > > >
> > > > scans look like in a 15 minute long test: https://imgur.com/a/YJepfcp
> > > >
> > > > Does anyone here know what could be causing this behaviour?
> > >
> > > Hmm, your email reminds me that the server you are testing against was
> > >
> > > having some issue before the holidays. So it may just be that it's
> > >
> > > crapping out and it has nothing to do with your connection.
> > >
> > > You could try adding a secondary ping flow (--test-parameter
> > >
> > > ping_hosts=one.one.one.one should do it) and see if that secondary flow
> > >
> > > also shows the same spikes. If it does, it's likely your connection, if
> > >
> > > not it's likely the server...
> > >
> > > -Toke
> > _______________________________________________
> > Make-wifi-fast mailing list
> > Make-wifi-fast@lists.bufferbloat.net
> > https://lists.bufferbloat.net/listinfo/make-wifi-fast
>
>
>
> --
> "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



-- 
"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

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

[Michael Yartys]

On Friday, January 15th, 2021 at 20:10, Dave Taht <dave.taht@gmail.com> wrote:

> oops meant to cc the list
>
> On Fri, Jan 15, 2021 at 11:09 AM Dave Taht dave.taht@gmail.com wrote:
>
> > On Fri, Jan 15, 2021 at 9:00 AM Michael Yartys via Make-wifi-fast
> >
> > make-wifi-fast@lists.bufferbloat.net wrote:
> >
> > > I assume that I got it right by running:
> > >
> > > flent --test-parameter ping_hosts=1.1.1.1 -l 300 netperf-eu.bufferbloat.net tcp_8down
> > >
> > > Either way, I think I'll have to do this test at another time since someone is streaming TV downstairs (via Ethernet!) and it really pollutes the results: https://imgur.com/a/F33LjeA
> >
> > I wouldn't say that pollutes the results, I'd say those are the
> >
> > typical and terrible results most users get when trying to do more
> >
> > than one thing at once on wifi or over the internet. Also it helps to
> >
> > have sqm on your isp updownlink, especially with netflix as it is
> >
> > bursty as heck
> >
> > I do not know if aql is enabled on that chipset. To my eye, it isn't,
> >
> > but the induced latency isn't quite high enough to represent what I
> >
> > viewed as the baseline problems.

Yup, AQL is enabled on this chipset, and I also have SQM piece_of_cake enabled to 50/50 mbps. I ran another test and made sure that there was no significant activity on the wireless network before I started it. Here are the results: https://imgur.com/a/7MzMVVJ

And the ping to 1.1.1.1 has the same shape: https://imgur.com/a/drcTGfv

Looks quite weird to me with all the oscillating latency spikes.
> >
> > https://forum.openwrt.org/t/aql-and-the-ath10k-is-lovely/59002
> >
> > Do a packet capture at the AP and look for multciast bursts especially

I think I'll have to find a moment where I have the network to myself again to be able to properly test things and figure out what might be causing this stuff. I'll probably do a packet capture at some point.

> >
> > And I keep trying to set aside time to go deep on AQL again, as the
> >
> > 7800 is a pretty popular box...
> >
> > > For what it's worth, the ping to 1.1.1.1 looks the same.
> > >
> > > Michael
> > >
> > > ‐‐‐‐‐‐‐ Original Message ‐‐‐‐‐‐‐
> > >
> > > On Friday, January 15th, 2021 at 17:23, Toke Høiland-Jørgensen toke@toke.dk wrote:
> > >
> > > > Michael Yartys via Make-wifi-fast make-wifi-fast@lists.bufferbloat.net
> > > >
> > > > writes:
> > > >
> > > > > Hi
> > > > >
> > > > > I decided to run a couple of flent 8-stream TCP downloads from
> > > > >
> > > > > netperf-eu.bufferbloat.net to my Fedora 33 laptop, and I noticed some
> > > > >
> > > > > weird periodic latency in the resulting graphs. My router is the
> > > > >
> > > > > NETGEAR R7800 running OpenWrt with an ath10k radio. Here's a graph
> > > > >
> > > > > that's representative of the results that I got:
> > > > >
> > > > > https://imgur.com/a/BOKNzht
> > > > >
> > > > > This looks similar to the latency spikes you would get from channel
> > > > >
> > > > > scans, but I have specified the BSSID in the Gnome network settings,
> > > > >
> > > > > which means that background scanning should be disabled. In addition,
> > > > >
> > > > > the test ran for 30 minutes, and channel scans are much more frequent
> > > > >
> > > > > than the latency spikes seen in the graph above. Here's what channel
> > > > >
> > > > > scans look like in a 15 minute long test: https://imgur.com/a/YJepfcp
> > > > >
> > > > > Does anyone here know what could be causing this behaviour?
> > > >
> > > > Hmm, your email reminds me that the server you are testing against was
> > > >
> > > > having some issue before the holidays. So it may just be that it's
> > > >
> > > > crapping out and it has nothing to do with your connection.
> > > >
> > > > You could try adding a secondary ping flow (--test-parameter
> > > >
> > > > ping_hosts=one.one.one.one should do it) and see if that secondary flow
> > > >
> > > > also shows the same spikes. If it does, it's likely your connection, if
> > > >
> > > > not it's likely the server...
> > > >
> > > > -Toke
> > >
> > > Make-wifi-fast mailing list
> > >
> > > Make-wifi-fast@lists.bufferbloat.net
> > >
> > > https://lists.bufferbloat.net/listinfo/make-wifi-fast
> >
> > --
> >
> > "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
>
> --
>
> "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

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

[Bob McMahon]

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If you want to isolate wifi from the router CPU, connect a device
(raspberry pi 4 to the lan switch) and run tests.

Also, for more detailed testing, sync the clocks to the GPS atomic clock
using pulse per second <https://www.satsignal.eu/ntp/Raspberry-Pi-NTP.html>
and try out some iperf 2.1 <https://sourceforge.net/projects/iperf2/>new
features.

Bob

On Fri, Jan 15, 2021 at 11:33 AM Michael Yartys via Make-wifi-fast <
make-wifi-fast@lists.bufferbloat.net> wrote:

> On Friday, January 15th, 2021 at 20:10, Dave Taht <dave.taht@gmail.com>
> wrote:
>
> > oops meant to cc the list
> >
> > On Fri, Jan 15, 2021 at 11:09 AM Dave Taht dave.taht@gmail.com wrote:
> >
> > > On Fri, Jan 15, 2021 at 9:00 AM Michael Yartys via Make-wifi-fast
> > >
> > > make-wifi-fast@lists.bufferbloat.net wrote:
> > >
> > > > I assume that I got it right by running:
> > > >
> > > > flent --test-parameter ping_hosts=1.1.1.1 -l 300
> netperf-eu.bufferbloat.net tcp_8down
> > > >
> > > > Either way, I think I'll have to do this test at another time since
> someone is streaming TV downstairs (via Ethernet!) and it really pollutes
> the results: https://imgur.com/a/F33LjeA
> > >
> > > I wouldn't say that pollutes the results, I'd say those are the
> > >
> > > typical and terrible results most users get when trying to do more
> > >
> > > than one thing at once on wifi or over the internet. Also it helps to
> > >
> > > have sqm on your isp updownlink, especially with netflix as it is
> > >
> > > bursty as heck
> > >
> > > I do not know if aql is enabled on that chipset. To my eye, it isn't,
> > >
> > > but the induced latency isn't quite high enough to represent what I
> > >
> > > viewed as the baseline problems.
>
> Yup, AQL is enabled on this chipset, and I also have SQM piece_of_cake
> enabled to 50/50 mbps. I ran another test and made sure that there was no
> significant activity on the wireless network before I started it. Here are
> the results: https://imgur.com/a/7MzMVVJ
>
> And the ping to 1.1.1.1 has the same shape: https://imgur.com/a/drcTGfv
>
> Looks quite weird to me with all the oscillating latency spikes.
> > >
> > > https://forum.openwrt.org/t/aql-and-the-ath10k-is-lovely/59002
> > >
> > > Do a packet capture at the AP and look for multciast bursts especially
>
> I think I'll have to find a moment where I have the network to myself
> again to be able to properly test things and figure out what might be
> causing this stuff. I'll probably do a packet capture at some point.
>
> > >
> > > And I keep trying to set aside time to go deep on AQL again, as the
> > >
> > > 7800 is a pretty popular box...
> > >
> > > > For what it's worth, the ping to 1.1.1.1 looks the same.
> > > >
> > > > Michael
> > > >
> > > > ‐‐‐‐‐‐‐ Original Message ‐‐‐‐‐‐‐
> > > >
> > > > On Friday, January 15th, 2021 at 17:23, Toke Høiland-Jørgensen
> toke@toke.dk wrote:
> > > >
> > > > > Michael Yartys via Make-wifi-fast
> make-wifi-fast@lists.bufferbloat.net
> > > > >
> > > > > writes:
> > > > >
> > > > > > Hi
> > > > > >
> > > > > > I decided to run a couple of flent 8-stream TCP downloads from
> > > > > >
> > > > > > netperf-eu.bufferbloat.net to my Fedora 33 laptop, and I
> noticed some
> > > > > >
> > > > > > weird periodic latency in the resulting graphs. My router is the
> > > > > >
> > > > > > NETGEAR R7800 running OpenWrt with an ath10k radio. Here's a
> graph
> > > > > >
> > > > > > that's representative of the results that I got:
> > > > > >
> > > > > > https://imgur.com/a/BOKNzht
> > > > > >
> > > > > > This looks similar to the latency spikes you would get from
> channel
> > > > > >
> > > > > > scans, but I have specified the BSSID in the Gnome network
> settings,
> > > > > >
> > > > > > which means that background scanning should be disabled. In
> addition,
> > > > > >
> > > > > > the test ran for 30 minutes, and channel scans are much more
> frequent
> > > > > >
> > > > > > than the latency spikes seen in the graph above. Here's what
> channel
> > > > > >
> > > > > > scans look like in a 15 minute long test:
> https://imgur.com/a/YJepfcp
> > > > > >
> > > > > > Does anyone here know what could be causing this behaviour?
> > > > >
> > > > > Hmm, your email reminds me that the server you are testing against
> was
> > > > >
> > > > > having some issue before the holidays. So it may just be that it's
> > > > >
> > > > > crapping out and it has nothing to do with your connection.
> > > > >
> > > > > You could try adding a secondary ping flow (--test-parameter
> > > > >
> > > > > ping_hosts=one.one.one.one should do it) and see if that secondary
> flow
> > > > >
> > > > > also shows the same spikes. If it does, it's likely your
> connection, if
> > > > >
> > > > > not it's likely the server...
> > > > >
> > > > > -Toke
> > > >
> > > > Make-wifi-fast mailing list
> > > >
> > > > Make-wifi-fast@lists.bufferbloat.net
> > > >
> > > > https://lists.bufferbloat.net/listinfo/make-wifi-fast
> > >
> > > --
> > >
> > > "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
> >
> > --
> >
> > "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
> _______________________________________________
> Make-wifi-fast mailing list
> Make-wifi-fast@lists.bufferbloat.net
> https://lists.bufferbloat.net/listinfo/make-wifi-fast

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

[Michael Yartys]

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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

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

[Dave Taht]

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

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

[Michael Yartys]

On Saturday, January 16th, 2021 at 18:48, 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.

The tests where I experienced the roller-coaster high latency were the result of a fluke I believe. It went away after a reboot and I wasn't readily able to reproduce it. Also, I believe there's some confusion here since my laptop, which was doing the background scans, has an Intel 7260AC card. ath10k is not at fault here (might have been during the fluke, but who knows).

> 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

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

[Dave Taht]

thxz for the clarification.

Also, I would really like the codel target reduced to 10ms on the
upcoming release of openwrt.

On Sat, Jan 16, 2021 at 10:01 AM Michael Yartys
<michael.yartys@protonmail.com> wrote:
>
> On Saturday, January 16th, 2021 at 18:48, 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.
>
> The tests where I experienced the roller-coaster high latency were the result of a fluke I believe. It went away after a reboot and I wasn't readily able to reproduce it. Also, I believe there's some confusion here since my laptop, which was doing the background scans, has an Intel 7260AC card. ath10k is not at fault here (might have been during the fluke, but who knows).
>
> > 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



-- 
"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

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

[Michael Yartys]

On Saturday, January 16th, 2021 at 19:06, Dave Taht <dave.taht@gmail.com> wrote:

> thxz for the clarification.

No worries! =)

>
> Also, I would really like the codel target reduced to 10ms on the
>
> upcoming release of openwrt.

I ran the 10ms target for a while but don't really remember whether I noticed that much of a difference. Maybe I should try it again? =)

Right now I'm planning to try out Toke's virtual time-based scheduler: https://github.com/tohojo/openwrt/blob/virtual-airtime/package/kernel/mac80211/patches/subsys/346-mac80211-Switch-to-a-virtual-time-based-airtime-sche.patch

>
> On Sat, Jan 16, 2021 at 10:01 AM Michael Yartys
>
> michael.yartys@protonmail.com wrote:
>
> > On Saturday, January 16th, 2021 at 18:48, 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.
> >
> > The tests where I experienced the roller-coaster high latency were the result of a fluke I believe. It went away after a reboot and I wasn't readily able to reproduce it. Also, I believe there's some confusion here since my laptop, which was doing the background scans, has an Intel 7260AC card. ath10k is not at fault here (might have been during the fluke, but who knows).
> >
> > > 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
>
> --
>
> "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

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

[Dave Taht]

On Sat, Jan 16, 2021 at 10:15 AM Michael Yartys
<michael.yartys@protonmail.com> wrote:
>
> On Saturday, January 16th, 2021 at 19:06, Dave Taht <dave.taht@gmail.com> wrote:
>
> > thxz for the clarification.
>
> No worries! =)
>
> >
> > Also, I would really like the codel target reduced to 10ms on the
> >
> > upcoming release of openwrt.
>
> I ran the 10ms target for a while but don't really remember whether I noticed that much of a difference. Maybe I should try it again? =)

you've got some good reference data now.

>
> Right now I'm planning to try out Toke's virtual time-based scheduler: https://github.com/tohojo/openwrt/blob/virtual-airtime/package/kernel/mac80211/patches/subsys/346-mac80211-Switch-to-a-virtual-time-based-airtime-sche.patch
>
> >
> > On Sat, Jan 16, 2021 at 10:01 AM Michael Yartys
> >
> > michael.yartys@protonmail.com wrote:
> >
> > > On Saturday, January 16th, 2021 at 18:48, 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.
> > >
> > > The tests where I experienced the roller-coaster high latency were the result of a fluke I believe. It went away after a reboot and I wasn't readily able to reproduce it. Also, I believe there's some confusion here since my laptop, which was doing the background scans, has an Intel 7260AC card. ath10k is not at fault here (might have been during the fluke, but who knows).
> > >
> > > > 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
> >
> > --
> >
> > "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



-- 
"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

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

[Bob McMahon]

[-- Attachment #1.1: Type: text/plain, Size: 2636 bytes --]

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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