1.7.0 slower?

Ruby JRuby
1

Hello everybody.
When trying out 1.7.0 to see if I could get that “speed boost” from
invoke dynamic, I tried this code:

with jruby 1.6.5 (ruby-1.8.7-p330) (2011-10-25 9dcd388) (Java
HotSpot™ 64-Bit Server VM 1.7.0_04) [Windows 7-amd64-java]

It takes this long: (jruby mandel.rb 500)

3.484393 seconds.

with jruby 1.7.0.preview2.dev (ruby-1.9.3-p203) (2012-06-14 fb4c77f)
(Java HotSpot™ 64-Bit Server VM 1.7.0_04) [Windows 7-amd64-java]

It takes this long:

6.029411 seconds.

With 2000, 1.6.5 takes 23.8s, 1.7.0 takes 25.2
With 4000, 1.6.5 takes 98.6s, 1.7.0 takes 90.0s

Any insights out there? Is this just a startup time slowdown? Also
shouldn’t I be seeing some kind of crazy speedup time because it’s using
1.7.0 with invokedynamic now?

Thanks.
-roger-

2

Very likely just a warmup time issue. Invokedynamic performance is more
sensitive to warmup because until indy call sites JIT they use a lot of
really slow code. That is supposed to improve in an upcoming release
(probably u8) but until then it should not be surprising to see cold
perf
looking much worse than non-indy.