Re: [linux-pm] Re: Hibernation considerations

Jeremy Maitin-Shepard
2007-07-20T22:49:07Z

Alan Stern <stern@rowland.harvard.edu> writes:

> On Fri, 20 Jul 2007, Jeremy Maitin-Shepard wrote:
>> >> when doing a suspend-to-ram you get to a point where you just don't use
>> >> any userspace.
>>
>> > What do you mean? How can you prevent user tasks from running? That's
>> > basically what the freezer does, and the whole point of this approach
>> > is to eliminate the freezer. Right?
>>
>> Presumably no tasks at all would be scheduled.

> How would you prevent tasks from being scheduled? How would you
> prevent drivers from deadlocking because in order to put their device
> in a low-power state they need to acquire a lock which is held by a
> user task?

Perhaps this isn't an issue once the device is already quiesced. I'm
just conjecturing.

[snip]

--
Jeremy Maitin-Shepard