On 2019-03-05 07:45, Toke Høiland-Jørgensen wrote:
Toke Høiland-Jørgensen <toke@xxxxxxxxxx> writes:
This switches the airtime scheduler in mac80211 to use a virtual
time-based
scheduler instead of the round-robin scheduler used before. This has a
couple of advantages:
- No need to sync up the round-robin scheduler in firmware/hardware
with
the round-robin airtime scheduler.
- If several stations are eligible for transmission we can schedule
both of
them; no need to hard-block the scheduling rotation until the head
of the
queue has used up its quantum.
- The check of whether a station is eligible for transmission becomes
simpler (in ieee80211_txq_may_transmit()).
The drawback is that scheduling becomes slightly more expensive, as we
need
to maintain an rbtree of TXQs sorted by virtual time. This means that
ieee80211_register_airtime() becomes O(logN) in the number of
currently
scheduled TXQs. However, hopefully this number rarely grows too big
(it's
only TXQs currently backlogged, not all associated stations), so it
shouldn't be too big of an issue.
Signed-off-by: Toke Høiland-Jørgensen <toke@xxxxxxxxxx>
---
This is basically the idea I mentioned earlier for a different way to
handle the airtime scheduling.
I've tested it on ath9k, where it achieves the same fairness and
weighing properties as the old scheduler. It would be good if you
could
test it on your ath10k setup, Rajkumar; and all of you please comment
on
whether you agree that this is better from an API point of view.
So no one has any comments on this? :)
Toke,
This is kind of design change. ;) FMU w.r.t ath10k, earlier deficit
adjustment
and list rotation happens at next_txq and may_transmit. Now it seems the
rbtree
adjustment happens upon new txq insertion through wake_txq and whenever
driver
reports airtime by register_airtime. Am I right?
We are using pretty old kernel (3.14, 4.4). It definitely needs backport
of rbtree.
Have you used *Wrt image or validation on x86?
-Rajkumar
