bug#37904: CPU overheating on recent laptops

bug#37904: CPU overheating on recent laptops

[Ludovic Courtès]

Hello,

I’ve had reports that Guix System on recent Dell laptops tends to lead
to overheating (with GNOME and all).

According to /sys/devices/system/cpu/cpu?/cpufreq/scaling_governor, all
the CPUs are running on the ‘performance’ governor by default, with
frequencies around 4 GHz (CPUs on these machines range from 400 MHz to
4.7 GHz).  So with just a load of 0.3 or so, the CPUs would be at ~65°C
(as reported by ‘sensors’) and the fans would start making noise.

If we explicitly change to the ‘powersave’ governor by writing to /sys,
frequencies go down and the machine behaves better.

However, I would expect UPower to do the right thing in the first
place.  Do you know what the story is here?  Are we missing some config
bits?

Also, there used to be an “ondemand” governor, which is no longer listed
in /sys/devices/system/cpu/cpu?/cpufreq/scaling_available_governors.
Was it removed or are we just missing a kconfig option?

Thanks,
Ludo’.

bug#37904: CPU overheating on recent laptops

[Tobias Geerinckx-Rice via Bug reports for GNU Guix]

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Ludo',

Ludovic Courtès 写道：
> Also, there used to be an “ondemand” governor, which is no 
> longer listed
> in 
> /sys/devices/system/cpu/cpu?/cpufreq/scaling_available_governors.

For laptops and other battery-powered devices, ‘conservative’ is 
preferred over ‘ondemand’.  It's probably a sane default choice 
for all.

> Was it removed or are we just missing a kconfig option?

Strange:

  ~ λ grep CPU_FREQ_GOV …/aux-files/linux-libre/5.3-x86_64.conf 
  CONFIG_CPU_FREQ_GOV_ATTR_SET=y
  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
  CONFIG_CPU_FREQ_GOV_SCHEDUTIL=y

What does cpufreq-info say?

Kind regards,

T G-R

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bug#37904: CPU overheating on recent laptops

[Ludovic Courtès]

Hi,

Tobias Geerinckx-Rice via Bug reports for GNU Guix <bug-guix@gnu.org>
skribis:

> Ludovic Courtès 写道：
>> Also, there used to be an “ondemand” governor, which is no longer
>> listed
>> in /sys/devices/system/cpu/cpu?/cpufreq/scaling_available_governors.
>
> For laptops and other battery-powered devices, ‘conservative’ is
> preferred over ‘ondemand’.  It's probably a sane default choice for
> all.

Oh, didn’t know that one.

>> Was it removed or are we just missing a kconfig option?
>
> Strange:
>
>  ~ λ grep CPU_FREQ_GOV …/aux-files/linux-libre/5.3-x86_64.conf
> CONFIG_CPU_FREQ_GOV_ATTR_SET=y
>  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
>  CONFIG_CPU_FREQ_GOV_SCHEDUTIL=y

Weird, I see:

--8<---------------cut here---------------start------------->8---
$ cat /sys/devices/system/cpu/cpu?/cpufreq/scaling_available_governors
performance powersave
performance powersave
performance powersave
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?

> What does cpufreq-info say?

On my laptop (plugged in) I have this:

--8<---------------cut here---------------start------------->8---
$ guix environment --ad-hoc cpufrequtils -- cpufreq-info
cpufrequtils 0.3: cpufreq-info (C) Dominik Brodowski 2004
Report errors and bugs to linux@brodo.de, please.
analyzing CPU 0:
  driver: intel_pstate
  CPUs which need to switch frequency at the same time: 0
  hardware limits: 400 MHz - 3.40 GHz
  available cpufreq governors: performance, powersave
  current policy: frequency should be within 400 MHz and 3.40 GHz.
                  The governor "performance" may decide which speed to use
                  within this range.
  current CPU frequency is 3.37 GHz.
analyzing CPU 1:
  driver: intel_pstate
  CPUs which need to switch frequency at the same time: 1
  hardware limits: 400 MHz - 3.40 GHz
  available cpufreq governors: performance, powersave
  current policy: frequency should be within 400 MHz and 3.40 GHz.
                  The governor "performance" may decide which speed to use
                  within this range.
  current CPU frequency is 3.25 GHz.
analyzing CPU 2:
  driver: intel_pstate
  CPUs which need to switch frequency at the same time: 2
  hardware limits: 400 MHz - 3.40 GHz
  available cpufreq governors: performance, powersave
  current policy: frequency should be within 400 MHz and 3.40 GHz.
                  The governor "performance" may decide which speed to use
                  within this range.
  current CPU frequency is 3.28 GHz.
analyzing CPU 3:
  driver: intel_pstate
  CPUs which need to switch frequency at the same time: 3
  hardware limits: 400 MHz - 3.40 GHz
  available cpufreq governors: performance, powersave
  current policy: frequency should be within 400 MHz and 3.40 GHz.
                  The governor "performance" may decide which speed to use
                  within this range.
  current CPU frequency is 3.31 GHz.
--8<---------------cut here---------------end--------------->8---

Thanks,
Ludo’.

bug#37904: CPU overheating on recent laptops

[Arne Babenhauserheide]

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Ludovic Courtès <ludo@gnu.org> 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)

Best wishes,
Arne
--
Unpolitisch sein
heißt politisch sein
ohne es zu merken

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bug#37904: CPU overheating on recent laptops

[Maxim Cournoyer]

Hi Ludo,

Arne Babenhauserheide <arne_bab@web.de> writes:

> Ludovic Courtès <ludo@gnu.org> 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

bug#37904: CPU overheating on recent laptops

[Ludovic Courtès]

Hi,

Maxim Cournoyer <maxim.cournoyer@gmail.com> skribis:

> 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?

Yes, looks like we can close it.

Thanks,
Ludo’.