rhizome VS yjit

There was actually an existing, similar in concept, Ruby JIT, Rhyzome: https://github.com/chrisseaton/rhizome.

It's good to see (IMO) the development of a JIT in a strict sense. I'm personally skeptical about the current approach (invoking a compiler separately).

On the other hand, it's important to know that JITs may take a long development time to be performant, and that they also complicate the performance profile of a virtual machine.

Lots of compiler tutorials are like this - there's very little out there to explain how compilers really work.

This is my effort - trying to show genuine data structures and processes.

https://github.com/chrisseaton/rhizome

Ruby 3.2.0 is here and it offers some nice additions to the language. One of the most exciting new things is the addition of a compiler, YJIT. YJIT was created by the folks from Shopify and has been producion tested for a while, so it is safe to use in your environment. Some benchmarks show the difference in speed compared to Ruby without YJIT. I'll put some links if you want to know more: https://speed.yjit.org/ https://www.solnic.dev/p/benchmarking-ruby-32-with-yjit

> I’m curious how the impact affects development, deployment, etc.

YJIT is pretty much transparent in production, if not it's likely a bug.

When we tried MJIT in production to compare it against YJIT, it causes lots of request timeouts on deploy, because the JIT warmup would take 10 to 20 minutes and it's much slower during that phase.

But YJIT warms ups extremely fast and with a much lower overhead, it's seemless on deploy.

The only thing you may need to tweak is `--yjit-exec-mem-size`, it defaults to `--yjit-exec-mem-size=256` (MB) which is not quite enough for larger apps.

As for development, it would work, but with code reloading enabled, you'd likely exhaust the executable memory allocation pretty fast, because for now YJIT doesn't GC generated code [0]. It will come soon, hopefully before the 3.1.0 release, but that's one of the reason why it's not enabled by default.

[0] https://github.com/Shopify/yjit/issues/87

Just want to temper expectations because YJIT is still new. But if you run into crashes or bugs, please open an issue with as much detail as you can: https://github.com/Shopify/yjit

You raised a point that the compiler only does a subset. That's actually what I would expect from a new project. I don't expect a full implementation to start. It takes time for a compiler to be mature enough to be general purpose. Here is another Ruby compiler in its infancy: https://github.com/Shopify/yjit.

We already collaborate extensively with GitHub around Rails and Ruby. Our respective Ruby and Rails infra teams hold regular meetings, and they already contributed substantial patches to YJIT, e.g. https://github.com/Shopify/yjit/pulls/jhawthorn. Also things like https://bugs.ruby-lang.org/issues/17763 are a collaboration.

Yes. I put some suggestions here. I realize that not all of them are practical, but refactoring specific hot methods could make a difference.