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

Daniel Walker
2010-05-07T21:30:20Z

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.

Daniel