Arch Linux

Gullible Jones

Member

Registered: 2004-12-29

Posts: 4,863

Kexec + suspend to RAM?

I just had a thought regarding Kexec... Suppose that, instead of requiring you to kill everything (e.g. by going single-user), the script that started kexec suspended applications. Couldn't this allow you to load a new kernel and do a software reboot without having to start everything up all over again?

Bralkein

Member

Registered: 2004-10-26

Posts: 354

Re: Kexec + suspend to RAM?

The following is all conjecture; I don't know much about this kind of thing:

Does a running kernel contain volatile information that is currently being used by the apps running at the time? If so, wouldn't at least some of the currently running programs need the kernel to remain in the same state? I do not think you would be able to reliably restore the same state in the newly-started kernel. There are probably many other problems with doing this. It doesn't sound like a simple thing.

I think it is an interesting idea, and I think with a lot of work it could maybe be possible, but I also think it might end up being a somewhat unreliable solution, and maybe it wouldn't be worth all the effort.

Gullible Jones

Member

Registered: 2004-12-29

Posts: 4,863

Re: Kexec + suspend to RAM?

Well, I'm not an expert but my idea in suspending everything was to eliminate that possibility... Not sure that would work.

There's another problem though, modules... I think the way to handle those would be to make a list of loaded modules, unload all modules, then load the modules in the list once ther new kernel was loaded. Again, I'm not an expert so I have no idea whether this is possible.