Exit(ing) through the YJIT

Transcript

1. EXIT(ing)
   
   
   Through
   
   
   the YJIT
   

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3. Eileen M. Uchitelle
   Twitter / GitHub:
   
   
   @eileencodes
   
   
   Mastadon:
   
   
   @[email protected]
   

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6. EXIT(ing)
   
   
   Through
   
   
   the YJIT
   

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7. What is a JIT?
   

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8. What is a JIT?
   "Just in time" compiler
   

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9. MJIT
   "Method-Based" JIT
   

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10. YJIT
    "Yet Another" JIT
    

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12. def call_method(arg)
    
    
    if arg == "hello"
    
    
    puts arg
    
    
    else
    
    
    puts "bye"
    
    
    end
    
    
    end
    
    
    YJIT only compiles
    
    
    code that is run
    

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13. def call_method(arg)
    
    
    if arg == "hello"
    
    
    puts arg
    
    
    else
    
    
    puts "bye"
    
    
    end
    
    
    end
    
    
    call_method("hello")
    
    
    YJIT only compiles
    
    
    code that is run
    

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14. def call_method(arg)
    
    
    if arg == "hello"
    
    
    puts arg
    
    
    else
    
    
    puts "bye"
    
    
    end
    
    
    end
    
    
    call_method("hello")
    
    
    YJIT only compiles
    
    
    code that is run
    

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15. def call_method
    
    
    able_to_compile
    
    
    not_able_to_compile
    
    
    end
    
    
    call_method
    YJIT can compile
    
    
    parts of methods
    

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16. def call_method
    
    
    able_to_compile
    
    
    not_able_to_compile
    
    
    end
    
    
    call_method
    YJIT can compile
    
    
    parts of methods
    

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17. def call_method
    
    
    able_to_compile
    
    
    not_able_to_compile
    
    
    end
    
    
    call_method
    YJIT can compile
    
    
    parts of methods
    

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18. How is YJIT
    implemented?
    

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19. MJIT vs YJIT
    Which to use?
    

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20. How can I use
    YJIT?
    

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21. $ docker pull rubylang/ruby:master-debug-
    nightly-focal
    Docker Images
    

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22. Pre-requisites
    • autoconf
    • make
    • bison
    • GCC or Clang
    • libyaml
    • [email protected]
    • Rust (for YJIT)
    • Ruby
    

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23. Run autogen
    $ cd ruby
    $ ./autogen.sh
    

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24. Configure Ruby
    $ ./configure
    --prefix=~/.rubies/ruby-yjit
    --with-openssl-dir=$(brew --prefix
    [email protected])
    --disable-install-doc
    

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25. Configure Ruby: Set prefix
    $ ./configure
    --prefix=~/.rubies/ruby-yjit
    --with-openssl-dir=$(brew --prefix
    [email protected])
    --disable-install-doc

    

    

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26. Configure Ruby: openssl
    $ ./configure
    --prefix=~/.rubies/ruby-yjit
    --with-openssl-dir=$(brew --prefix
    [email protected])
    --disable-install-doc
    

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27. Configure Ruby: Disable rdoc
    $ ./configure
    --prefix=~/.rubies/ruby-yjit
    --with-openssl-dir=$(brew --prefix
    [email protected])
    --disable-install-rdoc

    

    

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28. Install Ruby
    $ make install
    

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29. $ RUBY_YJIT_ENABLE=1 ruby my_script.rb
    $ ruby --yjit my_script.rb
    $ ruby --jit my_script.rb
    Enabling YJIT
    

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30. YJIT dev mode
    $ ./configure --enable-yjit=dev
    --prefix=~/.rubies/ruby-yjit
    --with-openssl-dir=$(brew --prefix
    [email protected])
    $ make install
    

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31. "Exit"
    When YJIT is
    
    
    unable to compile
    

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32. ar_demo.rb
    ActiveRecord::Base.establish_connection(
    
    
    adapter: "sqlite3", database: ":memory:")
    
    
    ActiveRecord::Schema.define do
    
    
    create_table :posts, force: true do |t|
    
    
    end
    
    
    end
    
    
    class Post < ActiveRecord::Base
    
    
    end
    
    
    class BugTest < ActiveSupport::TestCase
    
    
    def test_create
    
    
    Post.create!
    
    
    end
    
    
    end
    

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33. Running with stats enabled
    $ bundle exec ruby --yjit-stats ar_demo.rb
    

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38. But what does
    the code
    look like?
    

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39. "We can totally
    make that work."
    - Aaron Patterson
    

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40. Tracing YJIT
    Exits
    

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42. Tracing exits
    $ bundle exec ruby --yjit-trace-exits
    ar_demo.rb
    

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47. ar_demo.rb
    [...]
    
    
    class Post < ActiveRecord::Base
    
    
    def call_method(options)
    
    
    one, two, three = options
    
    
    end
    
    
    end
    
    
    class BugTest < ActiveSupport::TestCase
    
    
    def test_create
    
    
    post = Post.create!
    
    
    post.call_method("hello")
    
    
    end
    
    
    end
    

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48. Fixing broken code
    $ bundle exec ruby --yjit-trace-exits
    --yjit-call-threshold=1
    ar_demo.rb
    

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52. How will we
    use this?
    

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53. Optimizing YJIT
    

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54. yjit/src/codegen.rs
    /// Maps a YARV opcode to a code generation function (if
    supported)
    
    
    fn get_gen_fn(opcode: VALUE) -> Option {
    
    
    let VALUE(opcode) = opcode;
    
    
    let opcode = opcode as ruby_vminsn_type;
    
    
    assert!(opcode < VM_INSTRUCTION_SIZE);
    
    
    match opcode {
    
    
    [...]
    
    
    YARVINSN_send => Some(gen_send),
    
    
    YARVINSN_invokeblock => Some(gen_invokeblock),
    
    
    YARVINSN_invokesuper => Some(gen_invokesuper),
    
    
    YARVINSN_leave => Some(gen_leave),
    
    
    [...]
    

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55. yjit/src/codegen.rs
    /// Maps a YARV opcode to a code generation function (if
    supported)
    
    
    fn get_gen_fn(opcode: VALUE) -> Option {
    
    
    let VALUE(opcode) = opcode;
    
    
    let opcode = opcode as ruby_vminsn_type;
    
    
    assert!(opcode < VM_INSTRUCTION_SIZE);
    
    
    match opcode {
    
    
    [...]
    
    
    YARVINSN_send => Some(gen_send),
    
    
    YARVINSN_invokeblock => Some(gen_invokeblock),
    
    
    YARVINSN_invokesuper => Some(gen_invokesuper),
    
    
    YARVINSN_leave => Some(gen_leave),
    
    
    [...]
    

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56. yjit/src/codegen.rs
    asm.jne(
    
    
    counted_exit!(
    
    
    ocb, side_exit, invokesuper_block
    
    
    ).into()
    
    
    );
    
    
    

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57. Optimizing our
    Ruby Code
    

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58. Try YJIT
    on your app!
    

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59. Help us improve
    YJIT
    

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60. Eileen M. Uchitelle
    Twitter / GitHub:
    
    
    @eileencodes
    
    
    Mastadon:
    
    
    @[email protected]
    

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