From: Yukihiro Matsumoto Date: 2011-04-11T08:15:57+09:00 Subject: [ruby-core:35693] Re: caching of the ancestor chain Hi, In message "Re: [ruby-core:35692] Re: caching of the ancestor chain" on Mon, 11 Apr 2011 08:08:24 +0900, Charles Oliver Nutter writes: |What's actually slow about this? JRuby caches nothing but runs the |following benchmark 3x faster than 1.9.2p160 (and it's not Ruby |execution performance): CRuby does not cache neither. It's matter of how modules store mixin information. Currently mixin inserts hidden class into the class hierarchy. Since CRuby does not have reverse reference to the subclasses, there's no easy way to update the inserted hidden class when #include is called on an already included module. matz.