New Ruby impl based on PyPy...early perf numbers ahead of JRuby

[Charles Oliver Nutter]

On Sat, Feb 9, 2013 at 1:07 PM, Thomas Wuerthinger
<thomas.wuerthinger at oracle.com> wrote:
> Do you also have startup performance metrics - I assume the numbers below
> are about peak performance?

It seems to warm up very quickly; there's sometimes 2x slower perf on
the first iteration, but it rapidly settles. Overall startup time is
considerably better than JRuby.

> What is the  approximate % of language feature completeness of Topaz and do
> you think this aspect is relevant when comparing performance?

Hard to say. They consulted me and other Ruby implementers to learn
the most difficult features to implement, and made sure they put those
in place. But I've had a lot of trouble with these benchmarks,
partially due to missing language features.

The specific language features we recommended they implement before
measuring perf are mostly related to closure state and cross-frame
variable access. In JRuby, such things require allocation on the heap,
and since closure-receiving methods don't specialize (or do
context-sensitive caller-callee profiling) EA can't ever get rid of
those structures. The allocation and value indirection kills us.

- Charlie