Re: [PATCH 1/8] PM: Add suspend block api.

Matthew Garrett
2010-05-07T21:38:00Z

On Fri, May 07, 2010 at 02:30:20PM -0700, Daniel Walker wrote:
> On Fri, 2010-05-07 at 22:03 +0100, Matthew Garrett wrote:
>
> > Here's a different example. A process is waiting for a keypress, but
> > because it's badly written it's also drawing to the screen at 60 frames
> > per second and preventing the system from every going to idle. How do
> > you quiesce the system while still ensuring that the keypress will be
> > delivered to the application?
>
> To me it's somewhat of a negative for suspend blockers. Since to solve
> the problem you give above you would have to use a suspend blocker in an
> asynchronous way (locked in an interrupt, released in a thread too)
> assuming I understand your example. I've had my share of semaphore
> nightmares, and I'm not too excited to see a protection scheme (i.e. a
> lock) which allows asynchronous usage like suspend blockers.

Check the input patch for an example of this.

--
Matthew Garrett | mjg59@srcf.ucam.org