Controlling airtime fairness

Installing and Using OpenWrt Network and Wireless Configuration
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Given the last time this was discussed is in November 2017; a couple of things have changed regarding the subsystem.

I'm generally confused and in that airtime_flags in /sys/kernel/debug/ieee80211/phy0/ath10k/airtime_flags or /sys/kernel/debug/ieee80211/phy1/ath9k/airtime_flags now displays 3 instead. What does a value of 3 mean? Should it be 7 to be enabled?

The devices I have are an Archer A7v5 with a QCA988X and 956X for ath10k and ath9k respectively.

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I think this may answer your question?

Toke Høiland-Jørgensen•3 years ago

I assume you're talking about the flags, right? There are three of those, corresponding to the first three bits of the integer exposed in debugfs (and the 7 means they are all enabled by default). They are:

  • bit 1 (0x1): measure TX airtime
  • bit 2 (0x2): measure RX airtime
  • bit 3 (0x4): enable sparse station optimisation

They are not really tuning options, but rather debug parameters I added for testing

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For anyone (in the future) wanting to find the command to check that airtime fairness is running in their system, this command should return an output (ath10k and ath9k):

cat /sys/kernel/debug/ieee80211/phy0/netdev\:wlan0/stations/*/airtime
cat /sys/kernel/debug/ieee80211/phy1/netdev\:wlan1/stations/*/airtime
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Is this relevant to openwrt 19?

It looks like there is better stuff happening in linux years newer than those links. I look forward to a release with all this good stuff.
https://lists.bufferbloat.net/pipermail/make-wifi-fast/2019-December/002636.html

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In fact, I wanted to use these debug flags to test out the mailing list post you've shared.

I backported "Airtime Queue Limits" to backports-5.4-rc8 and ath10k-ct and it's working well on my Archer A7v5 running in a DumbAP config. I can feel the latency reduced quite a bit.

However, your quoted link is still in a preview stage and it ended up starving my device of memory when I backported it. It also ended up causing a lot of hostapd messages regarding mismatched/missed auth frames.

OpenWrt 19 uses backports-4.19 so it won't have these new features. Neither does master, until it gets updated with backports-5.5 or 5.6

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