From: Daniel DeLorme <dan-ml@...42.com>
Date: 2007-08-14T12:14:34+09:00
Subject: Re: Why don't Ruby libraries share memory?

Matt Harvey wrote:
> Sorry, I started talking about Rails again. The question is not about 
> Rails. The questions are: Is there any way we can have shared Ruby 
> libraries without turning the relevant code into a C extension? Is it 
> necessary that code be compiled to be put into shared memory by the OS? 

The problem goes further than that. Even if you were to load your libs 
in one process and then fork off worker processes (using copy-on-write 
to share loaded code), the gargabe collector writes to *every* page in 
memory when doing a garbage collecting run, thus negating the benefits 
of COW. It's fixed in 1.9, thankfully, but 1.8 is going to be a memory 
hog no matter which way you look at it.

Daniel