Re: Hibernation considerations

From: david
Date: Mon Jul 16 2007 - 02:56:22 EST


On Mon, 16 Jul 2007, Al Boldi wrote:


david@xxxxxxx wrote:
suspend-to-RAM should not involve kexec, the only reason for doing the
kexec to to get a seperate userspace to use for suspend-to-disk operations
instead of trying to partially freeze the sustem and keep useing it.

Or you could do suspend-to-disk-and-RAM. But in the above case, it was meant
to test kexec compatibility with device suspend/resume calls.

the point I am trying to make here is that there is no reason that the kexec approach needs to do _any_ suspend/resume calls.

all that is needed is the ability of the new kernel to initialize the devices it needs.

suspend-to-disk-and-ram could be implemented as three seperate steps

1. suspend-to-disk

2. resume-from-disk

3. suspend-to-ram

followed by either

4. resume-from-ram

or

4. battery dies and loptop powers off completely

5. power-on boot.

6. resume-from-disk

all that you need to do is to make sure that the system doesn't run anything that would affect permanent media or the outside world between steps #2 and #3

yes it's more steps, but each step is logicly seperate, and each step will be excercised on a regular basis, so the combination of the steps will also be reliable.

this is far better then creating yet another way to pause the system that only a few people will use.

David Lang
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