[Make-wifi-fast] [PATCH 0/2] ath9k: Add airtime fairness scheduler

Toke Høiland-Jørgensen toke at toke.dk
Fri Jun 17 05:17:34 EDT 2016

(Re-send to make-wifi-fast list due to a busted MX record).

This is the second version of my airtime fairness patch. This version
has a somewhat reworked scheduler (now closer to the structure of
fq_codel) and a different way to measure RX airtime; and there's a
debugfs entry to control which airtime measurements to include in the
scheduling decisions. For a simple one-way UDP test, the scheduler
achieves pretty much perfect airtime share (by its own measure). There's
not much throughput difference in the UDP case, but TCP tests see a
moderate improvement. I'll write up something more detailed on the
performance measures over the weekend and post it in a separate mail.

This patch set is rebased to mac80211-next - which means it no longer
includes Michal's patch to disable qdiscs. I have retained my version of
Tim's patch to make ath9k use wake_tx_queue in this patch set. That
probably needs some work still, but I believe he is working on that. I
have not tested extensively with the mac80211 FQ-CoDel patches enabled,
but I expect them to be complementary to this.

Changes since the RFC version:

- The scheduler will now enforce fairness harder. The previous version
  would refill the deficit of slow stations too fast in some cases.

- Change the way RX airtime is measured. For aggregates, the airtime is
  now calculated as the difference between the rs->rs_tstamp of the
  first and last frame in the aggregate. For non-aggregates, the
  previous calculation from the packet size is retained.

- There is now an 'airtime_flags' debugfs entry which can be used to
  control which airtime measures are accounted to the deficit. If bit 0
  is set, TX airtime will be accounted, and if bit 1 is set, RX airtime
  will. If no bits are set, the scheduler will revert to simple
  round-robin scheduling. The default is enabling both TX and RX.

- Squashed the whole thing into one patch and rebased to mac80211-next.

Toke Høiland-Jørgensen (2):
  ath9k: use mac80211 intermediate software queues
  ath9k: Add a per-station airtime deficit scheduler

 drivers/net/wireless/ath/ath9k/ath9k.h     |  34 +++-
 drivers/net/wireless/ath/ath9k/channel.c   |  12 +-
 drivers/net/wireless/ath/ath9k/debug.c     |   3 +
 drivers/net/wireless/ath/ath9k/debug.h     |  29 ++++
 drivers/net/wireless/ath/ath9k/debug_sta.c |  53 +++++-
 drivers/net/wireless/ath/ath9k/init.c      |   2 +
 drivers/net/wireless/ath/ath9k/main.c      |   7 +-
 drivers/net/wireless/ath/ath9k/recv.c      |  60 +++++++
 drivers/net/wireless/ath/ath9k/xmit.c      | 255 ++++++++++++++++++++++-------
 9 files changed, 386 insertions(+), 69 deletions(-)


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