[LAU] Ubuntustudio and frequency scaling

[Ralf Mardorf]

On Fri, 8 Jun 2018 08:25:08 -0700 (PDT), Len Ovens wrote:
>On Fri, 8 Jun 2018, Christopher Arndt wrote:
>
>> Am 08.06.2018 um 05:27 schrieb Ralf Mardorf:  
>>> On Thu, 07 Jun 2018 23:35:17 +0200, Michael Jarosch wrote:  
>>>> That's the old way you did it, but you can't do that with debian
>>>> and ubuntu, nowadays.  
>>> 
>>> As of what Ubuntu release it's not working anymore and what's the
>>> cause that it doesn't work anymore?  
>>
>> I'd be interested in an answer to this as well.  
>
>easiest place to look:
>/lib/systemd/set-cpufreq
>This is the way that ubuntu and probably debian set cpu governor
>today. Notice that they do not include Performance, If Performance is
>wanted at boot... the way to do that without getting errors when
>upgrading sw: create another file in the same directory maybe call it
>performance and use the same code, but replace all governor choices
>with performance. Then create a directory:
>/lib/systemd/system/ondemand.service.d
>in that directory create a file performance.conf will do and put some 
>lines like:
>------------------------8<---------------
>[Service]
>
>ExecStart=
>ExecStart=/lib/systemd/performance
>------------------------8<---------------
>Assuming the file you created was also called performance. The blank 
>ExecStart= is important as I found out, it resets Execstart to empty 
>first. Doing things this way has the advantage that 
>/lib/systemd/system/ondemand.service already makes sure the correct
>kernel modules are loaded first and updates will go smoothly.

This doesn't answer the two parts of my question. When stopped it
working using /sys/devices/system/cpu/cpu*/cpufreq/scaling_governor
from command line and why stopped it working.

Btw. unless the Ubuntu kernel configs didn't change, there's no need
to load a module at all, see

$ grep CPU_FREQ_GOV config-4.4.0-127-lowlatency 
CONFIG_CPU_FREQ_GOV_COMMON=y
CONFIG_CPU_FREQ_GOV_PERFORMANCE=y
CONFIG_CPU_FREQ_GOV_POWERSAVE=y
CONFIG_CPU_FREQ_GOV_USERSPACE=y
CONFIG_CPU_FREQ_GOV_ONDEMAND=y
CONFIG_CPU_FREQ_GOV_CONSERVATIVE=y