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Subject: Re: What PM should be and do (Was Re: Solving suspend-level
	confusion)
From: Nigel Cunningham <ncunningham@linuxmail.org>
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To: Pavel Machek <pavel@ucw.cz>
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Hi.

On Mon, 2004-08-09 at 02:54, Pavel Machek wrote:
> Hi!
> 
> > Yes. I'm not trying to give drivers an inconsistent state, just delaying
> > suspending some until the last minute....
> > 
> > Suspend 2 algorithm:
> > 
> > 1. Prepare image (freeze processes, allocate memory, eat memory etc)
> > 2. Power down all drivers not used while writing image
> > 3. Write LRU pages. ('pageset 2')
> > 4. Quiesce remaining drivers, save CPU state, to atomic copy of
> > remaining ram.
> > 5. Resume quiesced drivers.
> 
> Hmm, this means pretty complex subtree handling.. Perhaps it would be
> possible to make "quiesce/unquiesce" support in drivers so that this
> is not needed?

That would be great from my point of view. It's why I talked before in
terms of quiesced etc rather than S3, S4 and so on.

Nigel