Re: [RFC] sleepy linux

Ingo Molnar
2007-12-30T11:15:52Z

* Pavel Machek <pavel@ucw.cz> wrote:

> Todays hardware is mostly capable of doing better: with correctly set
> up wakeups, machine can sleep and successfully pretend it is not
> sleeping -- by waking up whenever something interesting happens. Of
> course, it is easier on machines not connected to the network, and on
> notebook computers.
>
> Requirements:
>
> 0) Working suspend-to-RAM, with kernel being able to bring video back.
>
> 1) RTC clock that can wake up system

very nice approach! It might require smarter hardware to be really
efficient, but the generic ability for Linux to utilize S3 automatically
would _quickly_ drive the creation of smarter hardware i'm sure - so i'd
propose to include this even if it wastes power in some cases.

a quick feature request: could you please make the wake-on-RTC
capability generic and add a CONFIG_DEBUG_SUSPEND_ON_RAM=y config option
(disabled by default) that does a short 1-second suspend-to-RAM sequence
upon bootup? That way we could test s2ram automatically (which is a MUCH
needed feature for automated regression testing and automatic
bisection). In addition, some sort of 'suspend for N seconds' /sys or
/dev/rtc capability would be nice as well.

btw., how far are you from having a working prototype?

Ingo