That's it exactly. This time the crazy hacks are in the Linux kernel and in CRIU (and they are there to stay, as they have broad utility), instead of in glibc (from which they might possibly be removed as emacs is the only use-case?).

https://lwn.net/Articles/673724/

On Mon, Jul 13, 2020 at 5:38 AM Stefan Monnier <monnier@iro.umontreal.ca> wrote:
> As the name suggests, it can provide you with the fastest emacs startup
> time in the west, by using CRIU checkpoint/restore to "clone" emacsen.

Hmmm... an "unexec" that's not Emacs-specific, interesting,


        Stefan