Re: live kernel upgrades (was: live kernel patching design)

Ingo Molnar
2015-02-22T10:48:47Z

* Ingo Molnar <mingo@kernel.org> wrote:

> We have many of the building blocks in place and have
> them available:
>
> - the freezer code already attempts at parking/unparking
> threads transparently, that could be fixed/extended.
>
> - hibernation, regular suspend/resume and in general
> power management has in essence already implemented
> most building blocks needed to enumerate and
> checkpoint/restore device state that otherwise gets
> lost in a shutdown/reboot cycle.
>
> - c/r patches started user state enumeration and
> checkpoint/restore logic

I forgot to mention:

- kexec allows the loading and execution of a new
kernel image.

It's all still tons of work to pull off a 'live kernel
upgrade' on native hardware, but IMHO it's tons of very
useful work that helps a dozen non-competing projects,
literally.

Thanks,

Ingo