aarch64 cpupower

[dk23]

cpupower does not seem to work on aarch64

$this->bbcode_second_pass_code('', ' uname -a
Linux tock 4.19.5-1-ARCH #1 SMP Tue Nov 27 17:33:26 MST 2018 aarch64 GNU/Linux

# cpupower frequency-info
analyzing CPU 0:
no or unknown cpufreq driver is active on this CPU
CPUs which run at the same hardware frequency: Not Available
CPUs which need to have their frequency coordinated by software: Not Available
maximum transition latency: Cannot determine or is not supported.
Not Available
available cpufreq governors: Not Available
Unable to determine current policy
current CPU frequency: Unable to call hardware
current CPU frequency: Unable to call to kernel
')

also the directory
$this->bbcode_second_pass_code('', '/sys/devices/system/cpu/cpu0/cpufreq')
is not present

I would like to set governor to performance

Thanks
dk23

[graysky]

I believe this is known limitation of aarch64 at the moment.

[lategoodbye]

Please look at https://github.com/lategoodbye/rpi-zero/issues/32 for more information.

[vap0rtranz]

Setting governors via the standard Linux processor devices works for me. I'm on a Mediatek 8173 SoC. And several governors are available, so it's just the cpupower utility that looks to be broke for that build of the aarch64 kernel? I've not build a kernel from source in awhile but I believe it was up to the build conf whether certain Linux system devices would be exposed via /sys?

This worked for me:

$this->bbcode_second_pass_code('', 'echo performance > /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor')

Tweaking CPU governors, frequency, or literally voltages, is usually a 'set and forget' scenario, so why does the cpupower utility need to work??

I wrap the above tweak into my rc.local. Set and forget.