[xfalcox]

Yeah, I was trying to come up with an idea for this. We try to eagerly load as much as we can before fork, so most of the memory is shared between the forked unicorns, but this won't work with YJIT right?

Ideally we would be able to eventually do the forks of a "mature" unicorn child an hour or so after all is JITed...

[byroot]

Beside the operational nightmare that it would be to deploy with such a strategy, it wouldn't work long term.

JITed code can be invalidated and recompiled, so your forks would still drift over time.

I'm a big proponent of unicorn (and forking setups in general) for various operational reasons, but I think JIT might be the last nail in the coffin.