Re: [linux-pm] Re: Hibernation considerations

[Jeremy Maitin-Shepard]

Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> 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
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