Here's a little ray of sunshine to temper all my grousing about performance: a benchmark that is comfortably faster than non-indy, and shows the down side of dynopt (specifically, that it slows down nontrivial benchmarks, presumably due to excessive bytecode size):
bench_evanphx_goruco.rb is a benchmark created by Evan Phoenix of the Rubinius project, another Ruby implementation for which Evan has built an optimizing mixed-mode JIT and generational GC. Rubinius currently does a better job of optimizing Ruby code (than JRuby) due largely to its ability to inline Ruby code (where stock JRuby never does). invokedynamic has and (probably) will continue to help us match or exceed Rubinius's raw Ruby execution performance. This benchmark is mostly an object-creation bench, to stress allocation and GC. In JRuby, however, the overhead of dispatch comes through in many places, and invokedynamic appears to help a good amount over stock CachingCallSite dispatch (and it's considerably better than dynopt): INDY: ~/projects/jruby ➔ jruby bench/bench_evanphx_goruco.rb 11.300000 0.000000 11.300000 ( 11.249000) 10.026000 0.000000 10.026000 ( 10.026000) 10.184000 0.000000 10.184000 ( 10.184000) 10.907000 0.000000 10.907000 ( 10.906000) 10.379000 0.000000 10.379000 ( 10.378000) NON-INDY: ~/projects/jruby ➔ jruby -Xcompile.invokedynamic=false bench/bench_evanphx_goruco.rb 12.500000 0.000000 12.500000 ( 12.448000) 11.454000 0.000000 11.454000 ( 11.454000) 11.910000 0.000000 11.910000 ( 11.909000) 11.305000 0.000000 11.305000 ( 11.305000) 11.331000 0.000000 11.331000 ( 11.331000) DYNOPT: ~/projects/jruby ➔ jruby -Xcompile.invokedynamic=false -Xcompile.dynopt=true bench/bench_evanphx_goruco.rb 12.982000 0.000000 12.982000 ( 12.887000) 12.363000 0.000000 12.363000 ( 12.363000) 12.431000 0.000000 12.431000 ( 12.431000) 12.490000 0.000000 12.490000 ( 12.490000) 12.344000 0.000000 12.344000 ( 12.344000) Nice results, and I know there's tons of improvements possible for the hot paths in this benchmark (both in JRuby and in Hotspot). Incidentally, my MLVM build is a good 25-30% faster than Java 6, even without invokedynamic use. Kudos to the entire Hotspot team for making every release almost inexplicably "just faster" than previous versions. - Charlie _______________________________________________ mlvm-dev mailing list mlvm-dev@openjdk.java.net http://mail.openjdk.java.net/mailman/listinfo/mlvm-dev
