[Make-wifi-fast] a bit of profiling on the archer

[Dave Taht]

I have not been profiling much on lower end platforms (it's hard, you
can crash a box
pretty easily with the wrong options or sample rates).

While watching the ath10k peak at 150-200mbits, at 99% of cpu in
softirq, I spent a bit
of time profiling various counters and statistics.

for this one (while downloading 12 flows at the same time via flent)

perf record -F 99 -e cpu-clock -ag -- sleep 10

perf report

  [[31m  67.81%[[m     0.00%  ksoftirqd/0  [kernel.kallsyms]       [k]
run_ksoftirqd
            |
            ---run_ksoftirqd
               |
               |[[31m--67.61%-- [[m__do_softirq
               |          |
               |          |[[31m--66.80%-- [[mnet_rx_action
               |          |          |
               |          |          |[[31m--41.07%-- [[mag71xx_poll

...

It appears we're spending 66% of the time in the *ethernet* portion of
the path.

I'm going to stop worrying so much about the performance of the new
wifi algorithms.

-- 
Dave Täht
Let's go make home routers and wifi faster! With better software!
http://blog.cerowrt.org