Not parent poster and do not have production YJIT experience. =)

My guess is that you would monitor `RubyVM::YJIT.runtime_stats[:code_region_size]` and/or `RubyVM::YJIT.runtime_stats[:code_gc_count]` so that you can get a feel for a reasonable value for your application, as well as know whether or not the "code GC" is running frequently.

https://github.com/ruby/ruby/blob/master/doc/yjit/yjit.md#pe...