[ath9k-devel] ath9k performance issues

[Felix Fietkau <nbd@openwrt.org>]

On 2011-04-05 5:44 PM, Bernhard Walle wrote:
> Hello,
>
> we're using a PCIe AR9280 card on a Octeon MIPS CPU. The system
> that does the transmission has a high CPU utilization:
>
> iperf in UDP mode with 50M bandwith has ~90 % CPU utilization with a
> high softirq proportion.
>
> Using an Intel card (5300) has a lower CPU utilization (~60 %), but it's
> no option to use it because the Linux driver has no access point mode.
>
> Are there any tweaks to decrease the CPU utilization with the ath9k
> driver? Any recommendations for the application to send the network
> packets more efficient?
What kernel version are you using? Are you using the in-kernel ath9k or 
are you using compat-wireless? I have added quite a few performance 
optimizations over time, as I'm working with much slower MIPS CPUs than 
the octeon.
In my tests, a 300 MHz MIPS 24K CPU is good enough for handling around 
90 mbit/s of traffic with only around 70% CPU utilization.

- Felix