High Performance Ruby

From Gogaruco 2012

Presenter: Charles Nutter

Bio

Charles works on JVM languages at Red Hat, focusing on Ruby but expanding to other languages soon. He has worked on JRuby for the past eight years and has been a JVM enthusiast since Java 1.0. Charles hopes to make JRuby the best Ruby implementation for high performance, big data, and heavy loads, and to use lessons learned from JRuby to help the JVM and other languages that run on it meet their potential.

Abstract

For years, the JVM has been the runtime to beat when it comes to runtime optimization and garbage collector performance. While statically-typed languages built atop the JVM have been able to leverage those capabilities, dynamic languages have often had a more difficult time. But the times they are a'changing.

Java 7 brings to the JVM a new and powerful feature called invokedynamic. With invokedynamic, dynamic languages no longer have an automatic performance penalty. The optimizations that make Java and other statically-typed JVM languages run fast now apply to dynamic languages just as well. Imagine a world where Ruby runs as fast as Java, with nearly zero GC overhead, true parallel threads, massive heap sizes, and rock-solid stability. That's the potential of invokedynamic, the JVM, and JRuby, and I'm going to show you how it all fits together.

Notes

• High Perf = faster than you need it to be.
• You hit a performance wall at some point.
• What we want:
  • Faster execution
  • Better GC
  • Parallel execution
  • Big data
• ...but we can't have these with the current way that C extensions are written.
• Different Appraoch:
  • Build our own runtime? YARV, Rubinius, MacRuby
  • Use an existing runtime? JRuby, MagLev, MacRuby, IronRuby
• It's "easy" to make a ew VM--but making it competitive is really, really, really hard.
• JVM
  • 15+ years of engineering by whole teams
  • FOSS
  • Fastest VM available
  • Best GCs available
  • Full parallel threading with guarantees
  • Broad platform support
• "But Java is slow"
  • Not anymore--it's literally as fast as C in many cases
  • In many cases it's the way the code is written
• JRuby
  • Java (and Ruby) implementation of Ruby on JVM
  • Same memory, threading model
  • JRuby JITs to JVM bytecode
  • It's been many, many years of hard work
• invokedynamic
  • Not just about invoking methods
  • Not just about dynamic typing
• JVM 101
  • 200 opcodes
• InvokeDynamic lets JRuby teach the JVM how ruby works
• Benchmarking is Hard
• Small code benchmarks very differently from large code
• Rails perf is a mixed bag right now.
  • Significant gains for some folks
  • Long warmup times for so much code
• The Future
  • JRuby will continue to get faster
  • Invoke Dynamic improvements at VM-level
  • Compiler improvements at Ruby level