Re: [PATCH 05/13] PM: Add option to disable /sys/power/state interface

["Rafael J. Wysocki" <rjw@sisk.pl>]

On Monday 09 February 2009, Uli Luckas wrote:
> On Monday 09 February 2009, Rafael J. Wysocki wrote:
> > On Sunday 08 February 2009, Pavel Machek wrote:
> > > Hi!
> > >
> > > > Being in suspend, where periodic user and kernel timers aren't running,
> > > > and random userspace threads aren't possibly spinning, rather than just
> > > > being in idle in the lowest power possible state, represent a pretty
> > > > significant power savings.
> > >
> > > If kernel timers fire too often, fix them. If user land spins, fix it,
> > > or SIGSTOP.
> > >
> > > And yes, autosleep is useful. That's why I done those "sleepy linux"
> > > patches.
> >
> > I agree, it is.  Still, I don't think the wakelocks in the proposed form
> > are the right way to implement it.
> >
> What do you think is the right approach then?

That depend on whether or not you want user space processes to be able to
prevent suspend from happening.

If I didn't, I'd use a reference counter.  If I did, I'd probably use a
special per-task flag or something similar.

Thanks,
Rafael