[ohm] OHM vs. PPM

[Marcel Holtmann]

Hi Kimmo,

> > >  > For the OHM vs GNOME Power Manager, I'd rather let Richard explain
> > >  > since he wrote those two, certainly with different designs in mind.
> > >
> > >  Right, the initial approach for OHM was to be system level because it
> > >  should also handle multiple session issues. And I don't see how this can
> > >  work if OHM itself would be part of a desktop session. I just wonder where
> > >  the request making OHM per session actually came from...
> > 
> > I wrote OHM in a few days to show a simple project that could be used
> > system wide for the nokia tablets or the OLPC laptop - it just wasn't
> > designed to be per-session like you guys are suggesting. Being blunt,
> > the session use-case is already being served by kpowersave,
> > gnome-power-manager and guidance-power-manager, so I really see OHM
> > fitting in system wide for the niche cases, not session wide for a
> > generic desktop.
> > 
> > For the embedded or server user case, a session wide daemon just
> > doesn't make sense IMO.
> 
> It'd be best to have only one OHM daemon running in the system, at least
> for the RAM-constrained embedded case. Session-specific policies could
> be implemented through configuration, interpreted policy language, or
> plugins. It should not be difficult to find out whose home directories
> to scan, and when, for session-specific configuration.

while it is possible to scan home directories, but that is a big no-no.
A system daemon interaction with the user should not be based on files
in users home directory. Use D-Bus if you wanna retrieve user input or
have the user set policies. Otherwise you have a big layer violation in
your design and not to talk about the potential security impact of doing
this.

Regards

Marcel