Re: Hibernation Redesign

[Jeremy Maitin-Shepard <jbms@cmu.edu>]

Al Boldi <a1426z@gawab.com> writes:

> Pavel Machek wrote:
>> We are stuck with refrigerator for now, and at least for hibernation,
>> I don't see any feasible alternative.

> Feasible alternative?

I posted such an alternative to the list a short time ago: hibenrating
from a *new* kernel space/user space that is created by loading a new
kernel in a manner similar to what is done for kexec crashdumps.  Unlike
kexec crashdumps, however, it would not require reserving any memory at
boot, because the necessary memory (maybe 16MB or 64MB) can be freed
just before hibernating, and device drivers can be properly stopped so
that DMAs don't stomp over certain memory.

This approach eliminates the need for the freezer, as it would make
hibernate look a lot a bit like suspend to ram from the perspective of
the "old" kernel (the kernel being hibernated), as the hibernate
operation itself would be completely atomic from the perspective of the
"old" kernel.  That is not to say, of course, that any code paths would
actually be shared, or that the drivers would do the same things
(because they probably would not).

[snip]

-- 
Jeremy Maitin-Shepard