[systemd-devel] systemd and power management

[Zbigniew Jędrzejewski-Szmek]

On Wed, Oct 29, 2014 at 01:00:42PM -0400, Daniel Hollocher wrote:
> Hey folks,
> I'm a not expert here, so please forgive the low quality/interest of my
> question.
> 
> I'm curious what the ideal systemd way is to set various power management
> settings in the /sys tree.  For me personally, I'm looking to set
> sampling_down_factor as without it, ondemand has terrible performance on my
> particular computer (a 10-30% loss compared to performance or conservative).
> 
> Currently, Ubuntu uses a sysv init script to set ondemand after boot, and I
> could edit that.  It would be cool to know the ideal systemd way, that
> could also be aware of power saving stuff.
> 
> From googling, it seems that tempfiles or sysctrl is not the way to go,
> since those only happen at boot.  Udev?  The examples I've found seem to
> make basic usage of udev to detect power changes, and then drop to a script
> to do the bulk of the work.  Is that it?

See sysctl.d(5).

Zbyszek