Kan Yan [off-list ref] writes:

quoted

I think this is a great approach, that we should definitely adopt in
mac80211. However, I'm not sure the outstanding airtime limiting should
be integrated into the fairness scheduling, since there are drivers such
as ath9k that don't need it.

Rather, I'd propose that we figure out the API for fairness scheduling
first, and add the BQL-like limiter as a separate layer. They can be
integrated in the sense that the limiter's estimate of airtime can be
used for fairness scheduling as well in the case where the
driver/firmware doesn't have a better source of airtime usage.

Does that make sense?

Sure that make sense. Yes, the airtime based BQL like queue limiter is
not needed for drivers such as ath9k. We could leave the outstanding
airtime accounting and queue depth limit to another subject and get
airtime fairness scheduling API done first.

Cool! I was thinking I would stub out an untested PoC in a separate
patch on my next submission, to show how I think this could be
incorporated. Have some other stuff to finish up this week, but
hopefully I'll have time to do the next version over the weekend :)

-Toke