From: Charles Oliver Nutter <charles.nutter@...>
Date: 2009-03-01T18:29:05+09:00
Subject: Re: Priorities for JRuby 1.3

James Britt wrote:
>> Well ... how about tuning the core engine for Rails / Merb and RSpec,
> 
> That's insane.
> 
> There's lots going on in Rubyland, and tuning the core engine for any 
> set of apps is evil.

My answer to tuning for either Rails or Merb is basically that it means 
tuning *everything* anyway. The reason JRuby has only recently started 
to post convincingly better numbers on Rails/Merb is because they're not 
Ruby execution-bound, they're solidly library-bound. So it's not how 
fast we can execute code, it's how optimized String or Array or Hash 
are. And that takes a lot longer.

I asked about execution performance because it's actually "easy" now for 
me to make Ruby execution as fast as anyone wants (I've got prototype 
code that's only a couple times slower than Java), but it has less and 
less impact on application performance. When Ruby execution perf is only 
10% of an app's run time, improving it 100-fold doesn't change a thing.

- Charlie