Subject: bug#37904: CPU overheating on recent laptops

From: Maxim Cournoyer <[email-masked]>
Date: Tue, 12 Jul 2022 10:49:18 -0400

Hi Ludo,

Arne Babenhauserheide <[email-masked]> writes:

> Ludovic Courtès <[email-masked]> writes:
>>> For laptops and other battery-powered devices, ‘conservative’ is
>>> preferred over ‘ondemand’.  It's probably a sane default choice for
>>> all.
>
>> --8<---------------cut here---------------start------------->8---
>> $ cat /sys/devices/system/cpu/cpu?/cpufreq/scaling_available_governors
>> performance powersave
>
>> $ uname -a
>> Linux ribbon 5.3.7-gnu #1 SMP 1 x86_64 GNU/Linux
>> --8<---------------cut here---------------end--------------->8---
>>
>> Do you see more governors on your side?  How could that be?
>
> Do you have a recent Intel CPU? From what I know they removed support
> for conservative, because their powersave is in fact conservative.
>
> Also they don’t necessarily stick to the frequency you set for them. To
> ensure that they keep the frequency, I have a script running that sets
> the speed every minute:
>
> (define cpupower-powersave-job
>   ;; Set the governor to powersave every minute.
>   ;; The job's action is a shell command.
>   ;; TODO: migrate to clearer syntax:   #~(job '(next-hour '(3)) (string-append #$btrfs-progs "/bin/btrfs scrub start -c 3 /")))
>   #~(job "* * * * *"            ;Vixie cron syntax
>          "cpupower frequency-set -g powersave -u 1200000")) ;; use powersave governor with a maximum frequency of 1200MHz
>
> (this is a problem which also hits other distributions)

Is this problem still an issue?  Based on what Arne says above, it seems
it isn't a fault in Guix, so perhaps we can close the issue and seek
resolution upstream if a problem remains?

Thanks,

Maxim