Subject: Re: SOC project idea
To: Manuel Bouyer <bouyer@antioche.eu.org>
From: Perry E. Metzger <perry@piermont.com>
List: netbsd-users
Date: 03/08/2007 16:59:48
Manuel Bouyer <bouyer@antioche.eu.org> writes:
>> A framework for hibernation is not too large a project.
>
> Maybe I'm missing somthing, but to resume from hibernation you'll load
> the kernel as a normal boot, and then restore state from a large file
> (or swap, or whatever). Then you need to be able to restore state of various
> parts of the kernel (sockets, open files, etc ...), which may not be at the
> same address as at hibernation time, because the kernel has done some work
> and rebooted in between.

That's one approach -- taking it to an extreme, one could checkpoint
all system processes and restart with a completely new kernel. Another
edge of the design space is to completely restore the (active) system
memory to the same contents they held just before the hibernate, with
no need to fix up anything more than one would have to after a deep
sleep like ACPI S3. I think the former is desirable, but the latter is
much easier to implement and more practical.

-- 
Perry E. Metzger		perry@piermont.com