Moving PowerDevil to kdereview

Friedrich W. H. Kossebau kossebau at
Thu Sep 4 19:28:15 BST 2008

Am Donnerstag, 4. September 2008, um 17:07 Uhr, schrieb Dario Freddi:
> > Am Freitag, 29. August 2008, um 19:45 Uhr, schrieb Dario Freddi:
> > > The core is the KDED module. Polling was removed thanks to a system
> > > that sets the polling time to the next upcoming idle event. Every time
> > > the polling function is called PowerDevil calculates the minimum time
> > > for an idle event to come, and sets the timer accordingly. For example,
> > > in a scenario where you have a lot of events in a small amount of time,
> > > PowerDevil polls the system every minute. For detecting system
> > > activity, it uses the same grabbing system used previously in
> > > KDE4Powersave.
> >
> > Please tell me where I am wrong:
> > So this is a per-user/session demon, right? But shouldn't this be a
> > per-system demon? How are things supposed to work if two or more users
> > are logged in at the same time, perhaps even running different
> > environments (KDE3, KDE4, GNOME, ...) which all try to react to system
> > changes?
> You have a point here. The behaviour of PowerDevil here is strictly
> connected to KDED behaviour. Anyway, I think the problem can't be avoided,
> since even if it was a system-wide daemon, it would conflict anyway with
> KPowersave, gnome- power-manager or whatever.

Should be solved, than. Perhaps by having such a demon on the systembus (if 
possible), implementing a (to be written) freedesktop spec. Have you looked 
at powersaved and similar? Oh wait, I have powersave running here, and there 
are already two interfaces on the systembus, "org.freedesktop.Policy.Power" 
and "com.novell.powersave".

Maybe you ask Danny Kukawka, the author of (K)PowerSave, what to do best. And 
what he is working on in this area, if there is a spec evolving.

> I don't have any ideas for 
> this, but I think it's the quirk about all power managers. The good point
> is that very rarely on laptops we have multiple users logged in at the same
> time, so this shouldn't be a huge issue.

I fear it is more huge than you wish. Many new home computers are laptops 
nower days (cool and movable). You also would like to manage power on a 
non-laptop computer. And a lot are used as multiuser machines. That is the 
power of Unix, let's not bury it.

E.g. I only own a laptop, and when having visitors who want to share it, they 
get an account of their own due to (my) privacy. And I almost never logout, 
hurra to working suspend and session-switching.

> > > The KCModule handles configuration of the Daemon. Having a dedicated
> > > application for it seemed to me redundant, since you can have it by
> > > using kcmshell4. PowerDevil has 2 kind of configuration: a general one,
> > > and a profile-based one. You can create new profiles and assign them to
> > > particular events, PowerDevil will take care of kicking them in at the
> > > right time.
> >
> > Cannot comment on the Plasma dependant parts, still:
> > > The KRunner acts like a shell of PowerDevil. By typing set-profile,
> > > set- governor and so on, you can change on the fly what you need.
> > >
> > > The Plasmoid should be what the system tray was for old Power managers,
> > > and it should basically have the same features as the KRunner.
> >
> > It would be great if one could control the currently used profile from
> > it, like possible with KPowerSave.
> It is already possible, if you type "power profile" KRunner lets you choose
> the profile you want to set. About the Applet, already planned ;)

Great :)

Okteta - KDE Hex Editor, coming to you with KDE 4.1

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