From: Charles Oliver Nutter <charles.nutter@...>
Date: 2007-09-28T11:29:43+09:00
Subject: Re: question on bottleneck of ruby

Yukihiro Matsumoto wrote:
> Hi,
> 
> In message "Re: question on bottleneck of ruby"
>     on Fri, 28 Sep 2007 09:18:33 +0900, Charles Oliver Nutter <charles.nutter@sun.com> writes:
> 
> |> Garbage collection and poor memory usage, on the other hand, are problems
> |> that can and should be solved.
> |
> |Very true, and I hope these are solved some time in future 1.9.1 
> |releases, because I worry that with YARV running faster and generating 
> |garbage faster, the GC bottlenecks are going to become more pronounced.
> 
> Although I have my own opinion, first, can you elaborate your opinion
> on GC problems and possible solutions?
> 
> Note that we already implemented generational GC, which happened to
> have no positive effect on performance due to write barrier cost.

I think part of the problem, as I understand it, is the "stop the world" 
nature of the GC. Because the GC can't run in parallel, it's more 
difficult to use Ruby for pauseless applications.

Unfortunately I can't really speak definitively on GC techniques, I've 
largely just heard stories from others about problems with Ruby's GC and 
issues with large or long-running apps. Can anyone else elaborate?

- Charlie