Kernel module arguments and custom /proc settings

Kernel module arguments and custom /proc settings

[Adam Bolte]

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Hello,

I have a machine that always overheats running GuixSD, and I would
like the fans to constantly run at maximum until I can find a better
solution.

The kernel module that enables fan control is thinkpad_acpi (which is
always loaded automatically), howerver manual fan control only works
if I set the module fan_control=1 argument when it loads. So I'm
looking for the equivalent of /etc/modprobe.d/ on Debian.

The module creates /proc/acpi/ibm/fan, which I can then write to (if
fan_control=1 was set) with the appropriate fan speed. I want to run
the equivalent of the following on boot:

# echo level full-speed > /proc/acpi/ibm/fan

In Debian this can be done by dropping the configuration into
/etc/sysctl.d/.

Is there a way to edit my config.scm file to make the above changes?

-Adam

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Re: Kernel module arguments and custom /proc settings

[Ludovic Courtès]

Hi,

Adam Bolte <abolte@systemsaviour.com> skribis:

> I have a machine that always overheats running GuixSD, and I would
> like the fans to constantly run at maximum until I can find a better
> solution.
>
> The kernel module that enables fan control is thinkpad_acpi (which is
> always loaded automatically), howerver manual fan control only works
> if I set the module fan_control=1 argument when it loads. So I'm
> looking for the equivalent of /etc/modprobe.d/ on Debian.
>
> The module creates /proc/acpi/ibm/fan, which I can then write to (if
> fan_control=1 was set) with the appropriate fan speed. I want to run
> the equivalent of the following on boot:
>
> # echo level full-speed > /proc/acpi/ibm/fan
>
> In Debian this can be done by dropping the configuration into
> /etc/sysctl.d/.
>
> Is there a way to edit my config.scm file to make the above changes?

Not really.

Looking at libkmod, it seems that /run/modprobe.d is automatically
scanned, like /etc/modprobe.d on Debian.  Could you try writing the
following in /run/modprobe.d/fan.conf:

--8<---------------cut here---------------start------------->8---
options thinkpad_acpi fan_control=1
--8<---------------cut here---------------end--------------->8---

and then rebooting?

If everything goes well, this .conf file will be taken into account when
udev asks to load ‘thinkpad_acpi’.

Eventually we should provide a way to specify /run/modprobe.d entries
via the ‘operating-system’ config, though.

HTH!

Ludo’.

Re: Kernel module arguments and custom /proc settings

[Adam Bolte]

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Sorry for the delay in my response. I've only just found the time to
try your suggestion and reply.

On Mon, Jul 25, 2016 at 10:47:36PM +0200, Ludovic Courtès wrote:
> Could you try writing the following in /run/modprobe.d/fan.conf:
> 
> --8<---------------cut here---------------start------------->8---
> options thinkpad_acpi fan_control=1
> --8<---------------cut here---------------end--------------->8---
> 
> and then rebooting?
> 
> If everything goes well, this .conf file will be taken into account when
> udev asks to load ‘thinkpad_acpi’.

I can confirm that this worked fine. Thanks!


> Eventually we should provide a way to specify /run/modprobe.d entries
> via the ‘operating-system’ config, though.

Sounds good. As someone who comes from a background in configuration
management, I would much rather have the entire system configuration
defined in a state configuration file than do manual once-off edits
(which is a part of what has attracted me to the project).

Now I just need to figure out how to set /proc entries on boot. I
guess I need to write a "service" for that, although I'm currently a
complete a noob at Scheme. Actually, that's why I purchased this X60
100% free software-compatible laptop - so I could better experiment
and learn these technologies.

Ultimately there are a number of programs I use under Debian which I
would like to create Guix packages for when I'm more comfortable with
how it all works. Then it's just a matter of finding the time to read
and experiment. :)

Cheers,
Adam

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Re: Kernel module arguments and custom /proc settings

[Ludovic Courtès]

Hi,

Adam Bolte <abolte@systemsaviour.com> skribis:

> On Mon, Jul 25, 2016 at 10:47:36PM +0200, Ludovic Courtès wrote:
>> Could you try writing the following in /run/modprobe.d/fan.conf:
>> 
>> --8<---------------cut here---------------start------------->8---
>> options thinkpad_acpi fan_control=1
>> --8<---------------cut here---------------end--------------->8---
>> 
>> and then rebooting?
>> 
>> If everything goes well, this .conf file will be taken into account when
>> udev asks to load ‘thinkpad_acpi’.
>
> I can confirm that this worked fine. Thanks!

Good!

>> Eventually we should provide a way to specify /run/modprobe.d entries
>> via the ‘operating-system’ config, though.
>
> Sounds good. As someone who comes from a background in configuration
> management, I would much rather have the entire system configuration
> defined in a state configuration file than do manual once-off edits
> (which is a part of what has attracted me to the project).

Agreed.

> Now I just need to figure out how to set /proc entries on boot. I
> guess I need to write a "service" for that, although I'm currently a
> complete a noob at Scheme.

Right, you need a service that extends ‘activation-service-type’ with a
snippet along the lines of:

  #~(call-with-output-file "/proc/something"
      (lambda (port)
        (display "whatever" port)))

Hopefully people can provide more guidance on IRC or on this list.

> Actually, that's why I purchased this X60 100% free
> software-compatible laptop - so I could better experiment and learn
> these technologies.
>
> Ultimately there are a number of programs I use under Debian which I
> would like to create Guix packages for when I'm more comfortable with
> how it all works. Then it's just a matter of finding the time to read
> and experiment. :)

Sounds good.  :-)

Thanks for your feedback,
Ludo’.

Re: Kernel module arguments and custom /proc settings

[Andreas Enge]

Hello,

On Sun, Jul 24, 2016 at 02:05:28PM +1000, Adam Bolte wrote:
> I have a machine that always overheats running GuixSD, and I would
> like the fans to constantly run at maximum until I can find a better
> solution.

a somewhat naive suggestion, since I did not yet try it myself: Could you
use fancontrol from the lm-sensors package? We might need to write a service
for it anyway for our new main server.

Andreas

Re: Kernel module arguments and custom /proc settings

[Adam Bolte]

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On Mon, Jul 25, 2016 at 11:09:41PM +0200, Andreas Enge wrote:
> On Sun, Jul 24, 2016 at 02:05:28PM +1000, Adam Bolte wrote:
> > I have a machine that always overheats running GuixSD, and I would
> > like the fans to constantly run at maximum until I can find a better
> > solution.
> 
> a somewhat naive suggestion, since I did not yet try it myself:
> Could you use fancontrol from the lm-sensors package? We might need
> to write a service for it anyway for our new main server.

Good question! I'll try to read up on the fancontrol daemon over the
weekend, and will report back if I have any luck with it. Thanks.

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