Re: Hibernation Redesign

Jeremy Fitzhardinge
2007-07-09T06:23:05Z

Jeremy Maitin-Shepard wrote:
> It would indeed be a pain for the new kernel to be loaded and have to
> use discontiguous memory. The trick is, though, that this is not
> necessary. Immediately before jumping to the new kernel, the first X
> bytes (where X is the amount of memory the new kernel will get,
> typically 16MB or 64MB) of physical memory are backed up into the
> arbitrary discontiguous pages that are made available. This will not
> take very long, because copying even 64MB of memory is extremely fast.
> Then the new kernel is free to use the first X bytes of contiguous
> physical memory. Problem solved.
>

You could also use the paravirt_ops pte hooks to create a mapping from
linear "physical" addresses to actual machine pages. This is what a Xen
kernel needs to do, and all the infrastructure will be in place shortly.

J