Re: [RFD] Automatic suspend

Pavel Machek
2009-02-16T22:58:31Z

Hi!

> The recent descussion about the Android PM patches sent by Arve shows that
> there is a need to introduce a mechanism allowing us to:
> (1) automatically put the system as a whole into a sleep state (eg. suspend to
> RAM) when it is found to be "idle", where the meaning of "idle" has to be
> defined too,

Well; I'd prefer to keep the interface very minimal.

If no devices are being used, and next wakeup is far enough in the
future, just put system to sleep. Long enough == so far away that
suspend/wakeup is short compared to that... like 20 seconds on PC.

Ok, it probably needs to be opt-in: echo auto-mem > /sys/power/state
should do the trick.

This will need either fixing all the applications not to poll, or
maybe someone SIGSTOP-ing apps that are in background and poll too
often.

> (2) put given subset of devices into low power states whenever they are not
> used, without putting the entire system into a sleep state.

Arjan said this nicely...

Pavel

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