Gluttonous

YARV Progress Report

Posted by kev Sat, 15 Oct 2005 02:29:00 GMT

Koichi SASADA

Caution! (review)

• I can’t speak English well
  • If I say strange English, you can see the slide page ** Or ask another Japanese. They can speak English well.
  • If you have any queestions, ask me with: ** Japanese (recommended) ** Ruby, C, Scheme, Java, … ** IRC (#rubyconf on freenode)

Agenda

• Self Introduction and Japanese Activities
• Overview of YARV
• Goal of YARV
• Current YARV status
  • YARV Design, Optimization Review
  • Evaluation
• Conclusion

Self Introduction

• “SASADA” the family name
• “Koichi” is given name -> “ko1”
• A Student for Ph.D. 2nd grade (Not a Son-shi)
  • Systems Software for Multithreaded Arch ** SMT/CMP or other tech ** i.e.: Hypter threeading (Intel), CMT (Sun), Power (IBM) ** OS, Library, Compiler and Interpreter ** YARV is my first step for parallel interpreter
  • Computer Architecture for Next Generation at Public Position
• Nihon Ruby no Kai
  • Organized by Mr. Takahashi (maki)
• “Rubyist Magazine”:http://jp.rubyist.net/magazine
  • vol 10 at 10 Oct 2005
  • 1st anniversary at 6 Sep 2005 (vol 9)
• Ruby-dev summary
• English Diary some days
  • But retired

Our Activity: Rubyist Magazine

• Many Japanese articles related to Ruby
  • Cooperate with Ruby Code & Style?
  • I’m writing YARV internal named “YARV Maniacs”
• Many interviews of Japanese Rubyists

RubyMa!

• Published 1 Apr 2005 (April Fools)
  • Joke web-zine
• Parody of Negima!
• Many useful articles
  • The Takahashi method: def Takahashi end

Overview of YARV

Overview: Background

• Ruby is used world-wide, (one of)? the most comfortable programming languages
• Ruby is slow, because interpreter doesn’t use Virtual Machine Technology

• We need Ruby VM!

• “YARV: Yet Another Ruby VM”:http://www.atdot.net/yarv/

  • Started development on 1 Jan 2004 ** At that time, there were some VMS for Ruby
• Ruby’s license, of course

Overview: FAQ (review of last year FAQ)

• Q: How is “YARV” pronounced?
• A: You can pronounce “YARV” what you like.
• Q: Should I remember the name “YARV”?
• A: No. If YARV succeeds, it gets renamed to Rite, if it doesn’t, no one will remember it
  • About YARV, name is NOT ???

Overview: YARV System

Ruby Program –> Compiler –> YARV Instruction Sequence –> ==> Virtual Machine ==> AOT Compiler –> C Source –>

Overview: Current Interpreter

• Ruby Program: a = b + c
• Syntax tree: (a =) -> (method dispatch + (b), (c))
• Current interpreter traverses AST directly

Overview YARV - Stack Machine

The Goal of YARV

• YARV: Yet Another RubyVM -> The RubyVM
  • To be the Ruby 2.0 VM Rite
• Fastest Ruby Interpreter
  • Easy to be the current Ruby interpreter

The Goal of YARV (cont.)

• Support all Ruby features
  • Include Ruby 2.0 new syntaxes
• Native thread support
  • Concurrent execution (Giant VM lock)
  • Parallel execution on parallel machine
• Multi-VM instance
  • Same as Mutlti-VM in Java

Goal: Ruby 2.0 syntax

• Matz will decide it :-)
• ”{|…| …}” == “->(…){ … }”
  • “I think this is ugly” – Ko1
• Multiple-values
  • Same as Array? Or first class multiple-values support?
• Selector-namespace?

Goal: Native Thread Support

• Three different thread models
• Model 1: User-level thread (green)
  • same as current Rubt interpreter
• Model 2: Native thread with giant VM lock
  • Same as current Ruby interpreter
  • Easy to implement
• Model 3: Native-thread with fine grain lock
  • Run ruby threads in parallel
  • For enterprise?

Goal: Native Thread Support (cont.)

h5. Current Ruby Interpreter & Model 1

• CPU1: Thread 1 -> Thread 2 -> Thread 1
• CPU2: Idle……..

h5. Model 2: Native thread with Giant VM Lock

• CPU1: Thread 1 -> (Lock) -> (in OS thread 2) Thread 2 -> (Lock) -> Thread 1
• CPU2: Idle……..

On this system, other threads can run (but the Ruby threads switch cpus with a lock)

h5. Model 3: Native thread with Fine Grain Lock

• CPU1: Thread 1……
• CPU2: Thread 2……

Goal: Native Thread Support Summary

|. |. Model 1|. Model 2|. Model 3| |Scalability|Bad|Bad?|Best |Lock overhead|No|Some|High| |Impl. Difficulty|Norm|Easy|Hard| |Portability|Good|Bad|Bad|

Goal: Multi-VM Instance

• Current Ruby process: ( Process ( Ruby Interpreter (VM) ) )

• Ruby Process with Multi-VM Instance ( Process ((many) Ruby Interpreter (VM) ) )

• Current Ruby can hold only 1 interpreter in 1 process

  • Interpreter structure causes this problem
  • Using many global variables

• Multiple-VM instance

  • Running some VM in 1 process
  • It will help ruby embedded apps ** mod_ruby, etc.

Multi-VM Instance + Thread Model 2

CPU1: Thread 1 -> (Lock of VM1) -> Thread 2 -> Lock of VM1

Goal: Load Map

• All Ruby features support
  • Feb. 2006 … ?
• Native Thread Support
  • Experimental: Dec. 2005
  • Complete: 2006?(model 2) 2007?(model 3)
• Multi-VM support
  • Experimental Feb 2006
  • Complete: 2006?

Current Status of YARV

Status: System

Some almosts, an incomplete and a not yet

Status: Supported Ruby Features

• Almost all Ruby features
• Not supported:
  • Few syntaxes … {|*arg| …}
  • Visibility
  • Safe level ($SAFE)
  • Some methods written in C for current Ruby implementation
  • Around Signal
  • C extension libraries ** (Because YARV can’t run mkmf.rb)

Status: Versions

• 0.2 YARV as C Extension
  • Need a patch to Ruby interpeter
• 0.3 (2005-8): YARV as Ruby Interpreter
  • merged to Ruby source (1.9 HEAD)
  • Maintained on my subversion repository
• Latest version: 0.2
  • Native thread (pthread / Win32) supports model 2

YARV 0.2.x

(Ruby Interpreter (Evaluator)) -> YARV (Compiler, VM, Optimizer) -> back

YARV 0.3.x

• YARV marged with Ruby Interpreter

• Future work

  • Generational GC
  • m17n
  • …

“Status: Compile & Disasm CGI”:http://www.atdot.net/yc/

Status: VM Design

• 5 registers
  • PC: Program Counter
  • SP: Stack Pointer
  • CFP: Controler Frame Pointer
  • LFP: LOcal frame pointer
  • DFP: Dynamic Frame Pointer
• Some stack frame
• Control stack and value stack

Status: Optimization

• Simple Stack Virtual Machine
  • Re-design Exception handling
• Peep-hole optimization on compile time
  • I gave up static program analysis
  • Dynamicity is your friend but my ENEMY!
• Direct Threaded code with GCC
• Specialized Instruction
  • i.e. Ruby program “x+y” compiled to special instruction instead of a method dispatch instruction
• In-line Cache
  • In-line Method Cache
  • In-line constant value cache ** Because ruby’s “constant variable” is not constant!
• Embed values in an instruction sequence
• Unified Instruction
  • Operands Unification
  • *InsnA x -> InsnA_x
• Unified instructions are auto generated by VM gen
  • I only decide which instructions should be combined
• Stack Caching
• JIT Compilation
  • I made easy one for x86, but…
  • Too hard to do alone. I retired.
• AOT Compilation
  • YARV bytecode -> C Source
  • Easy to develop
  • Hard to support exception

Status: Demo

• YARV building demo?
• YARV running demo?

Status: Evaluation

• Yield block is not fast (2-3 times faster than C Ruby) - optimizing this will be work for the future
• With all optimizations, basic math can see a 50 times performance gain over C Ruby
• Ackermann can see 20 times gain over C Ruby
• Wow - YARV as it stands stacks up really well against other interpreters for basic math type stuff

Status: Awards

• 2004: Funded by IPA Exploratory Software Development “Youth”
  • IPA: Information-technology Promotion Agency, Japan
• 2005: Funded by IPA Exploratory Software Development (continuance)
• 2004: got awarded “Super creator” from IPA

Conclusion

• YARV supports almost all Ruby syntax
• YARV suppoorts some RUby libraries
• YARV 0.3.2 supports native thread
• YARV achieves significant speedup for ruby programs which have VM bottleneck
  • This means that we can enjoy Symbol programming with Ruby

Conclusion: Future Work

• Support all Ruby features
  • mkmf.rb
• Support every thread model
  • especially 2 and 3
• Support multi-VM Instance

How Can You Help me

• Any comments are welcome
  • Build reports, Bug reports, architecture reports, …
• yarv-devel Mailing List
  • English ML for YARV development ** Matz and other Japanese join
• “YARV Wiki”:http://yarv.rubyforge.org/pukiwki/pukiwiki.php
• Give me a job! (I’ll finish my course 2 years later)

Special Thanks

• Matz the architect of Ruby
• IPA: His sponsor
• YARV development ML subs
• All rubyists

Q&A

• All: We want the demo!

  • ko1: OK

• Derek Sivers: A bunch of Japanese :-)

  • ko1: Some more Japanese