Re: Hibernation Redesign

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

Al Boldi <a1426z@gawab.com> writes:

[snip]

> Exactly, there may well be overlap between Xen and the kexec hibernate 
> approach, for which code structures should definitely be leveraged.

> And, I wasn't suggesting to use Xen as an HV, which wouldn't really solve 
> anything, but was trying to point out that there is no need to maintain two 
> separate kernels, much like Xen, which inlines two modes into the kernel:  
> host and guest.

With relocatable kernels, or by simply using the "backup the first 16 or
64 MB of physical memory" approach, the same kernel image could be used
both as the normal kernel as the "save image" kernel.  The actual
behavior of the system would likely depend on kernel command-line
parameters or an initrd, rather than being hard-coded into the kernel
image.  If it is made a requirement that the same kernel be used, then
as is done currently, the text sections need not be touched at all.
There is a significant advantage, however, to using a different kernel:
unneeded drivers can be compiled out, leading to faster load times.

> So kexec really seems the way to go, which mimics the way APM used to do it, 
> which is known to work flawlessly with minimal OS involvement.

Now all that is needed is someone with enough time and interest to
implement it.  :)

-- 
Jeremy Maitin-Shepard