On Wed, Apr 15, 2020 at 06:45:26AM -0700, 0x6d6174 wrote:
> Hi everyone.
> 
> I'm running also an APU2 board with an Atheros wlan chipset:
> 
> athn0 at pci5 dev 0 function 0 "Atheros AR9281" rev 0x01: apic 5 int 16
> athn0: AR9280 rev 2 (2T2R), ROM rev 22, address XX:XX:XX:XX:XX:XX
> 
> I also used an ALIX board with an Atheros wlan chipset (AR9280).
> >From OpenBSD 6.0 to 6.6 (-stable) (iirc OpenBSD 5.9 had a slightly better
> performance) the wlan performance didn't change for me. 
> 
> I use the following test setup:
> 
> PC <---   100mbps / 1gbps lan ---> ALIX / APU2 board <--- Atheros wlan --->
> Notebook
> 
> # cat /etc/hostname.athn0
> media autoselect mode 11g mediaopt hostap chan 3
> nwid test wpa wpakey wpasecret
> wpaprotos wpa2 wpaciphers ccmp wpagroupcipher ccmp powersave
> up
> 
> 
> For simplicity I disable pf and use a bridge interface that uses the lan and
> wlan interfaces. Also I always send files with scp from my PC to my notebook
> for performance measurements.

Thanks, this is interesting.

Can you try your test again without WPA?
OpenBSD's athn(4) driver does not offload crypto to hardware yet.
I suspect this explains your observations below.

> The ALIX board has a wlan throughput of about 2.4 - 3.2 mbps while the APU2
> has a wlan throughput of about 12 - 14 mbps. I noticed by running top -S,
> that if I transfer lets say a 1000MB file, then for both boards softnet has
> a CPU usage of 100%, thus I suspected that the wlan bandwidth for an Atheros
> chip correlates to the CPU usage of softnet (because the APU2 board has a
> better CPU it has a higher wlan throughput). If I send a 1000MB file from
> one lan interface to another lan interface, then softnet has a CPU usage of
> about 20% and the file transfer has a throughput of almost 1gbps. Thus I
> suspect the high CPU usage of softnet has something to do with the TX
> performance of the atheros driver implementation.
> 
> For a quick test I enabled pf and used traffic sharping to reduce the wlan
> troughput:
> queue std on "athn0" bandwidth 5M max 10M default
> 
> Now when I transfer a file softnet has a CPU usage of about 70-73% for the
> APU2 board (the wlan throughput is about 10 - 11 mbps).
> 
> Also I found an interesting performance report, that pfSense could reach
> about 90 mbps with the same hardware that I have (APU2 board with the same
> wlan card) see [1], unfortunately I don't have the time to verify it. If
> that's true, then the next step I want to do is a diff of the driver
> implementations and hopefully understand why pfSense has a much higher
> throughput.
> 
> [1]
> https://teklager.se/en/knowledge-base/compex-wle200nx-wle600vx-benchmark/
> 
> best regards,
> Mat
> 
> 
> 
> --
> Sent from: http://openbsd-archive.7691.n7.nabble.com/openbsd-user-misc-f3.html
> 
> 

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