Re: [PATCH 0/8] Suspend block api (version 8)

Alan Stern
2010-05-27T19:22:34Z

On Thu, 27 May 2010, Peter Zijlstra wrote:

> On Thu, 2010-05-27 at 18:40 +0100, Matthew Garrett wrote:
> > On Thu, May 27, 2010 at 07:34:40PM +0200, Peter Zijlstra wrote:
> > > > we still need to be able to enter suspend while the system isn't idle.
> > >
> > > _WHY_!?
> >
> > Because if I'm running a kernel build in a tmpfs and I hit the sleep
> > key, I need to go to sleep. Blocking processes on driver access isn't
> > sufficient.
>
> But that's a whole different issue. I agree that a forced suspend for
> things like that make sense, just not for power managing a running
> system.

Why not? Or rather, why shouldn't it?

> PC style hardware like that doesn't wake up from suspend for
> funny things like a keypress either (good thing too).

Yes it does. If I close the lid of my laptop, wait a few seconds for
it to suspend, then open the lid (which does not wake it up), and hit a
key -- it wakes up.

> Anyway all that already works (more or less), so I don't see the
> problem.

The "less" part is the problem. It would be nice to have a forced
suspend mode that is more dicriminating: Instead of activating
immediately it would wait until all pending events were handled.

Alan Stern