[Make-wifi-fast] Support for airtime scheduling using ath10k

[Miguel Catalan Cid]

Hi,

Do we need to use a specific firmware? It's ok to use the last one from
kvalo, or should we use the one from candelatech?

Best,
Miguel.

El lun., 29 jun. 2020 a las 12:26, Toke Høiland-Jørgensen (<toke at redhat.com>)
escribió:

> Miguel Catalan Cid <miguel.catalan at i2cat.net> writes:
>
> > El mar., 23 jun. 2020 a las 11:35, Toke Høiland-Jørgensen
> > (<toke at redhat.com>) escribió:
> >>
> >> Miguel Catalan Cid <miguel.catalan at i2cat.net> writes:
> >>
> >> > Hi,
> >> >
> >> > we are trying to apply different airtime weights to different
> stations in
> >> > order to have some prioritization among connected stations. While
> this is
> >> > working pretty well with ath9k, with ath10k we always obtain a fair
> >> > distribution of the airtime (i.e. 50%-50% in the case of two
> stations),
> >> > regardless of the airtime weight specified.
> >> >
> >> > E.g. STA1:
> >> > RX: 0 us
> >> > TX: 2295610622 us
> >> >
> >> > *Weight: 200*Deficit: VO: 256 us VI: 256 us BE: 34 us BK: 256 us
> >> >
> >> > E.g. STA2:
> >> > RX: 0 us
> >> > TX: 162597077 us
> >>
> >> 2295610622/162597077 ~= 14
> >>
> >> which is not *too* far from the 20/1 ratio you've configured? Does the
> >> ratio change at all when you change the weights (i.e., if they are
> >> equal, do you get closer to a 50/50 split?).
> >>
> >> Do the two stations have roughly the same signal strength / rate?
> >
> > In this case I started the STA1 a bit earlier, so it had a higher
> > airtime aggregate. Indeed, to compare the airtime share, I was
> > continuously monitoring the "airtime rate" (i.e. the difference
> > between Airtime(now) and Airtime (now-4s)) and the results of both
> > STAs were the same (i.e. 50/50 split) independently of the weight
> > being used. But when using ath9k the same test runs perfectly
> > according to the weights.
> >
> >>
> >> > *Weight: 10*Deficit: VO: 256 us VI: 256 us BE: 9 us BK: 256 us
> >> >
> >> > We are using Compex WLE650V5-18A cards.
> >> >
> >> > So, does ath10k support airtime scheduling? In such a case, do we need
> >> > specific Wi-Fi cards?
> >>
> >> It should. My guess would be that maybe you're not getting enough
> >> backpressure for the scheduler to actually enforce things correctly. You
> >> could try to look at the TXQ output and see if you actually have any
> >> drops ('iw dev wlan0 station dump -v' and look at the drops/marks
> >> columns).
> >
> > ok, i will check!
>
> Another thing to check is the value of 'new_flows' in the TXQ output; if
> that is high, it indicates that the queues run empty a lot, which can
> prevent the airtime fairness scheduler from working properly.
>
> >> What kernel version are you running? If it's not new enough to have AQL,
> >> that might help moving the backlog to where the scheduler can do more
> >> with it.
> >
> > Kernel 5.5.5.
>
> Hmm, that should have AQL, actually.
>
> -Toke
>
>

-- 
Miguel Catalán Cid, PhD

Mobile Wireless Internet Group (MWI)
i2CAT Foundation, Barcelona, Spain
http://www.i2cat.net/
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.bufferbloat.net/pipermail/make-wifi-fast/attachments/20200630/15847bf4/attachment.html>