[maemo-developers] suspendprocess - poor man's power save

[From: Ville M. Vainio]

On Sun, Sep 12, 2010 at 9:47 AM, Attila Csipa <maemo at csipa.in.rs> wrote:

> It has been difficult for many developers to comply with many of the recommended
> power-saving practices for Maemo, especially those porting apps from desktop
> environments. I'm not sure how many of you noticed already, but in the best
> hack-tradition of the N900 mikkov made a suspendprocess package, not unlike
> what was talked about on this list - which could allow many of these power-
> guzzling apps to become a little more suspend-power-friendly with little to no
> effort.
>
> http://maemo.org/packages/package_instance/view/fremantle_extras-
> devel_free_armel/suspendprocess/0.1/
>
> Basically it is a launch-wrapper that SIGSTOPs and resumes the app it started
> based on the DBUS signals.
>
> I would recommend all interested parties to take a look and if it
> improves/helps in their apps/packages, apply it to them (or report any
> problems/improvement suggestions, naturally). It's not the prettiest solution
> and native level DBUS solution is of course still preferred by far, but if you
> don't have that time or luxury (or are blessed with SDL code or similar), this
> might come handy.


Quoting everything because this is an old email (and not everyone
still has it around).

It's an intriguing hack, and I'm somewhat curious about people's
thoughts about the following:

1) Will native dbus solution *really* be better in all cases? Or would
suspending the process actually help move a sleeping process to swap
more aggressively than just blocking?

2) Perhaps this would be even more useful to keep multitasking memory
usage at bay - by suspending the processes not in foreground (by their
own volition of course)?

3) It seems to be implemented in python + somewhat heavy libs
(gobject, osso). C + libdbus implementation  would be more convenient,
esp. if this turns out to be a popular approach.

-- 
Ville M. Vainio @@ Forum Nokia