[ath9k-devel] Debugging very slow ath9k AP performance

[Ben Greear <greearb@candelatech.com>]

I am seeing very slow performance when I have around 100
stations connected to an AP (ath9k on both ends).

It seems like the station side is doing fine, but on the
AP side, it appears there are always lots of pending frames
and it is only transmitting about 100 pkts per second if my stats
are correct.

Kernel is 3.3.1+ with the troublesome ath9k patch reverted.

I would be greatful for any pointers as to what might be
causing this slowdown.


[root at lanner-atom ~]# cat /debug/ieee80211/wiphy0/ath9k/xmit
Num-Tx-Queues: 10  tx-queues-setup: 0x10f poll-work-seen: 7113  Off-Channel: No
                             BE         BK        VI        VO

MPDUs Queued:            77539          0         0      7717
MPDUs Completed:         77213          0         0      7584
MPDUs XRetried:            326          0         0       133
Aggregates:             391465          0         0         0
AMPDUs Queued HW:         1080          0         0         0
AMPDUs Queued SW:       588156          0         0         0
AMPDUs Completed:       503120          0         0         0
AMPDUs Retried:        1033333          0         0         0
AMPDUs XRetried:         85992          0         0         0
FIFO Underrun:               0          0         0         0
TXOP Exceeded:               0          0         0         0
TXTIMER Expiry:              0          0         0         0
DESC CFG Error:              0          0         0         0
DATA Underrun:               0          0         0         0
DELIM Underrun:              0          0         0         0
TX-Pkts-All:            666651          0         0      7717
TX-Bytes-All:        816440297          0         0    633824
hw-put-tx-buf:          952507          0         0      5766
hw-tx-start:                 0          0         0         0
hw-tx-proc-desc:             0          0         0         0
TX-Failed:                   0          0         0         0
txq-memory-address:   f6bc1df0   f6bc1e8c  f6bc1d54  f6bc1cb8
axq-qnum:                    2          3         1         0
axq-depth:                   2          0         0         0
axq-ampdu_depth:             2          0         0         0
axq-stopped                  1          0         0         0
tx-in-progress               0          0         0         0
pending-frames             123          0         0         0
txq_headidx:                 3          0         0         6
txq_tailidx:                 3          0         0         6
axq_q empty:                   1          1         1         1
axq_acq empty:                 0          1         1         1
txq_fifo[0] empty:             1          1         1         1
txq_fifo[1] empty:             0          1         1         1
txq_fifo[2] empty:             0          1         1         1
txq_fifo[3] empty:             1          1         1         1
txq_fifo[4] empty:             1          1         1         1
txq_fifo[5] empty:             1          1         1         1
txq_fifo[6] empty:             1          1         1         1
txq_fifo[7] empty:             1          1         1         1
txq[2] first-ac: f3da7a00 sched: 1
  first-tid: f3da73c8 sched: 1 paused: 0

-- 
Ben Greear <greearb@candelatech.com>
Candela Technologies Inc  http://www.candelatech.com