YJIT Makes Rails 1.7x faster / RubyKaigi 2024

RubyKaigi 2024 https://rubykaigi.org/2024/

Transcript

1. YJIT Makes Rails 1.7x Faster @k0kubun
3. YJIT Makes Rails 1.7x Faster @k0kubun 1.8x
4. @k0kubun
5. Ruby Infra team paracycle tenderlove eileencodes eightbitraptor peterzhu2118 kddnewton maximecb XrXr k0kubun nirvdrum rwstauner
6. Ruby Infra team GC Prism YJIT Lead
7. May 15th - 17th, 2024 NAHA CULTURAL ARTS THEATER NAHArt, Okinawa, Japan
8. ✦ Production-ready JIT for CRuby ✦ JIT: Just-In-Time Compiler ✦ Speeds up methods that are called 30+ times YJIT
9. Shopify StoreFront
 Ruby 3.3 YJIT vs Interpreter
11. ✦ --yjit ✦ RUBY_YJIT_ENABLE=1 ✦ RubyVM::YJIT.enable (Ruby 3.3+) ✦ Rails 7.2 will call this in a default initializer Enabling YJIT
12. ✦ --yjit-exec-mem-size ✦ Default: 48MiB (since Ruby 3.3.1) ✦ tip: Try 32MiB, 24MiB, or 16MiB ✦ YJIT uses 3-4x of --yjit-exec-mem-size ✦ 2-3x is used for metadata Minimizing YJIT's memory usage
14. May 15th - 17th, 2024 NAHA CULTURAL ARTS THEATER NAHArt, Okinawa, Japan Ruby 3.3 (and 3.4)
 YJIT optimizations
15. ✦ What is the most impactful Ruby 3.3 YJIT optimization? ✦ The PR made Railsbench 7% faster Ruby 3.3 YJIT optimizations
18. May 15th - 17th, 2024 NAHA CULTURAL ARTS THEATER NAHArt, Okinawa, Japan Method Call Fallbacks
19. def foo(a) @foo = bar(a) end Ruby Code
20. def foo(a) @foo = bar(a) end Ruby Code putself getlocal :a send :bar dup setivar @foo leave Ruby VM Instructions
21. def foo(a) @foo = bar(a) end Ruby Code putself getlocal :a send :bar dup setivar @foo leave Ruby VM Instructions JIT Code jit_putself jit_getlocal :a jit_send :bar jit_dup jit_setivar @foo jit_leave
22. def foo(a) @foo = bar(a) end Ruby Code putself getlocal :a send :bar dup setivar @foo leave Ruby VM Instructions JIT Code JIT: 100% jit_putself jit_getlocal :a jit_send :bar jit_dup jit_setivar @foo jit_leave
23. def foo(a) @foo = bar(**a) end Ruby Code putself getlocal :a send :bar, ** dup setivar @foo leave Ruby VM Instructions
24. def foo(a) @foo = bar(**a) end Ruby Code putself getlocal :a send :bar, ** dup setivar @foo leave Ruby VM Instructions JIT Code jit_putself jit_getlocal :a side_exit
25. def foo(a) @foo = bar(**a) end Ruby Code putself getlocal :a send :bar, ** dup setivar @foo leave Ruby VM Instructions JIT Code jit_putself jit_getlocal :a side_exit JIT: 33% Interpreter: 67%
26. def foo(a) @foo = bar(**a) end Ruby Code putself getlocal :a send :bar, ** dup setivar @foo leave Ruby VM Instructions JIT Code jit_putself jit_getlocal :a vm_send :bar
27. def foo(a) @foo = bar(**a) end Ruby Code putself getlocal :a send :bar, ** dup setivar @foo leave Ruby VM Instructions JIT Code JIT: 100% jit_putself jit_getlocal :a vm_send :bar jit_dup jit_setivar @foo jit_leave
28. ✦ Ruby 3.3: Use the interpreter’s C function (like MJIT) for: ✦ Unsupported calls ✦ Megamorphic calls ✦ Fallbacks allow the subsequent code to be compiled Method Call Fallbacks
29. ✦ Ruby 3.3: Use the interpreter’s C function (like MJIT) for: ✦ Unsupported calls ✦ Megamorphic calls ← What’s this? ✦ Fallbacks allow the subsequent code to be compiled Method Call Fallbacks
30. class X def call @x = x end end class A < X def x = :a end :a if self.class == A Ruby Code Ruby 3.2 YJIT
31. class X def call @x = x end end class A < X def x = :a end class B < X def x = :b end :a if self.class == A Ruby Code Ruby 3.2 YJIT :b if self.class == B
32. class X def call @x = x end end class A < X def x = :a end class B < X def x = :b end class C < X def x = :c end :a if self.class == A Ruby Code Ruby 3.2 YJIT :b if self.class == B :c if self.class == C
33. class X def call @x = x end end class A < X def x = :a end class B < X def x = :b end class C < X def x = :c end class D < X def x = :d end :a if self.class == A Ruby Code Ruby 3.2 YJIT :b if self.class == B :c if self.class == C side exit
34. class X def call @x = x end end class A < X def x = :a end class B < X def x = :b end class C < X def x = :c end class D < X def x = :d end :a if self.class == A Ruby Code Ruby 3.2 YJIT :b if self.class == B :c if self.class == C side exit :a if self.class == A :b if self.class == B :c if self.class == C vm_send :x Ruby 3.3 YJIT setivar @x
35. May 15th - 17th, 2024 NAHA CULTURAL ARTS THEATER NAHArt, Okinawa, Japan Exception Handlers
37. ✦ In CRuby, exception handlers are executed differently from regular methods ✦ Ruby 3.3 YJIT added support for them in CRuby JITs for the first time ✦ "Exceptions" are not necessarily Ruby exceptions, e.g. break/return in blocks Exception Handlers
38. def foo(arr) @foo = arr.each do |a| break a if a.odd? end end Ruby 3.2
39. def foo(arr) @foo = arr.each do |a| break a if a.odd? end end getlocal arr send :each, block dup setivar @foo leave getlocal a send :odd? branchunless L0 getlocal a throw TAG_BREAK leave L0: putnil leave Ruby 3.2 <main> Call Stack
40. def foo(arr) @foo = arr.each do |a| break a if a.odd? end end getlocal arr send :each, block dup setivar @foo leave getlocal a send :odd? branchunless L0 getlocal a throw TAG_BREAK leave L0: putnil leave <main> Call Stack Ruby 3.2 foo
41. def foo(arr) @foo = arr.each do |a| break a if a.odd? end end getlocal arr send :each, block dup setivar @foo leave getlocal a send :odd? branchunless L0 getlocal a throw TAG_BREAK leave L0: putnil leave <main> Call Stack Ruby 3.2 foo Array#each
42. def foo(arr) @foo = arr.each do |a| break a if a.odd? end end getlocal arr send :each, block dup setivar @foo leave getlocal a send :odd? branchunless L0 getlocal a throw TAG_BREAK leave L0: putnil leave <main> Call Stack Ruby 3.2 foo Array#each block in foo
43. def foo(arr) @foo = arr.each do |a| break a if a.odd? end end getlocal arr send :each, block dup setivar @foo leave getlocal a send :odd? branchunless L0 getlocal a throw TAG_BREAK leave L0: putnil leave <main> Call Stack Ruby 3.2 foo Array#each block in foo
44. def foo(arr) @foo = arr.each do |a| break a if a.odd? end end getlocal arr send :each, block dup setivar @foo leave getlocal a send :odd? branchunless L0 getlocal a throw TAG_BREAK leave L0: putnil leave <main> Call Stack Ruby 3.2 foo
45. def foo(arr) @foo = arr.each do |a| break a if a.odd? end end getlocal arr send :each, block dup setivar @foo leave getlocal a send :odd? branchunless L0 getlocal a throw TAG_BREAK leave L0: putnil leave Ruby 3.2 JIT: 60% Interpreter: 40%
46. def foo(arr) @foo = arr.each do |a| break a if a.odd? end end getlocal arr send :each, block dup setivar @foo leave getlocal a send :odd? branchunless L0 getlocal a throw TAG_BREAK leave L0: putnil leave Ruby 3.3 JIT: 100%
47. May 15th - 17th, 2024 NAHA CULTURAL ARTS THEATER NAHArt, Okinawa, Japan Register Allocator for Stack Values
49. ✦ Ruby 3.2 YJIT writes VM stack values onto memory ✦ Ruby 3.3 YJIT allocates registers for them Register Allocator for Stack Values
50. def three 1 + 2 end Ruby 3.2
51. def three 1 + 2 end putobject 1 putobject 2 opt_plus leave Ruby 3.2 Memory Register A Register B
52. def three 1 + 2 end putobject 1 putobject 2 opt_plus leave Ruby 3.2 Memory Register A Register B 1
53. def three 1 + 2 end putobject 1 putobject 2 opt_plus leave Ruby 3.2 Memory Register A Register B 1 2
54. def three 1 + 2 end putobject 1 putobject 2 opt_plus leave Ruby 3.2 Memory Register A Register B 3
55. def three 1 + 2 end putobject 1 putobject 2 opt_plus leave Ruby 3.2 Memory Register A Register B
56. def three 1 + 2 end putobject 1 putobject 2 opt_plus leave Ruby 3.3 Memory Register A Register B
57. def three 1 + 2 end putobject 1 putobject 2 opt_plus leave Ruby 3.3 Memory Register A Register B 1
58. def three 1 + 2 end putobject 1 putobject 2 opt_plus leave Ruby 3.3 Memory Register A Register B 1 2
59. def three 1 + 2 end putobject 1 putobject 2 opt_plus leave Ruby 3.3 Memory Register A Register B 3
60. def three 1 + 2 end putobject 1 putobject 2 opt_plus leave Ruby 3.3 Memory Register A Register B
61. ✦ Ruby 3.4 YJIT: Optimize local variables like stack values, speculating Kernel#binding is not called ✦ Ruby 3.4 will hopefully allocate registers for them too (under development) Register Allocator for Local Variables
62. May 15th - 17th, 2024 NAHA CULTURAL ARTS THEATER NAHArt, Okinawa, Japan Method Inlining for Ruby
64. ✦ YJIT 3.3+ inlines single-line methods that return: ✦ Ruby 3.3: 1, 2, 3, …, true, false, nil, :symbol ✦ Ruby 3.4: self, local variables Method Inlining for Ruby
65. Active
 Support
66. Active
 Support
67. Active
 Support
68. Symbol#to_sym
69. Sorbet Helper Patches
70. May 15th - 17th, 2024 NAHA CULTURAL ARTS THEATER NAHArt, Okinawa, Japan Method Inlining for C
72. ✦ Ruby 3.3 YJIT specializes many C methods, which leads to a high C method inlining ratio ✦ Ruby 3.4 YJIT pushes "lazy frames" Method Inlining for C
76. ✦ Enable YJIT in production now! ✦ YJIT speeds up production apps by 10-20% ✦ Upgrade Ruby to 3.3 ✦ JIT more code, allocate registers, and inline method calls Conclusion