Upgrade to Pro — share decks privately, control downloads, hide ads and more …

Deoptimization: How YJIT Speeds Up Ruby by Slow...

Avatar for Takashi Kokubun Takashi Kokubun
April 16, 2025
Programming
2
3.3k

Deoptimization: How YJIT Speeds Up Ruby by Slowing Down / RubyKaigi 2025

https://rubykaigi.org/2025

Avatar for Takashi Kokubun

Takashi Kokubun

April 16, 2025
Tweet

More Decks by Takashi Kokubun

See All by Takashi Kokubun
YJIT Makes Rails 1.7x faster / RubyKaigi 2024
Avatar for Takashi Kokubun k0kubun
7
14k
Ruby JIT Hacking Guide / RubyKaigi 2023
Avatar for Takashi Kokubun k0kubun
2
10k
YJIT: Dive into Ruby's JIT compiler written in Rust / Rust.Tokyo 2022
Avatar for Takashi Kokubun k0kubun
2
2.2k
Towards Ruby 4 JIT / RubyKaigi 2022
Avatar for Takashi Kokubun k0kubun
3
11k
Optimizing Production Performance with MRI JIT / RubyConf 2021
Avatar for Takashi Kokubun k0kubun
1
480
Why Ruby's JIT was slow / RubyKaigi Takeout 2021
Avatar for Takashi Kokubun k0kubun
3
2k
数時間かかる週一リリースを毎日何度も爆速でできるようにするまで / CI/CD Conference 2021
Avatar for Takashi Kokubun k0kubun
21
14k
Ruby 3 JIT's roadmap / RubyConf China 2020
Avatar for Takashi Kokubun k0kubun
0
830
Ruby 3.0 JIT on Rails
Avatar for Takashi Kokubun k0kubun
9
9.4k

Other Decks in Programming

See All in Programming
Ruby Parser progress report 2025
Avatar for yui-knk yui_knk
1
460
Reading Rails 1.0 Source Code
Avatar for Masafumi Okura okuramasafumi
0
250
@Environment(\.keyPath)那么好我不允许你们不知道！ / atEnvironment keyPath is so good and you should know it!
Avatar for Elvis Shi lovee
0
130
チームのテスト力を鍛える
Avatar for Hiroki Iseri goyoki
3
930
Swift Updates - Learn Languages 2025
Avatar for Yuta Koshizawa koher
2
510
詳解！defer panic recover のしくみ / Understanding defer, panic, and recover
Avatar for convto convto
0
250
そのAPI、誰のため？ Androidライブラリ設計における利用者目線の実践テクニック
Avatar for mkeeda mkeeda
2
2.8k
請來的 AI Agent 同事們在寫程式時，怎麼用 pytest 去除各種幻想與盲點
Avatar for Keith Yang keitheis
0
130
「待たせ上手」なスケルトンスクリーン、 そのUXの裏側
Avatar for teamLab teamlab
PRO
0
570
パッケージ設計の黒魔術/Kyoto.go#63
Avatar for kadota kyohei lufia
3
440
GitHubとGitLabと AWS CodePipelineで CI/CDを組み比べてみた
Avatar for Satoshi Kaneyasu satoshi256kbyte
4
250
Processing Gem ベースの、2D レトロゲームエンジンの開発
Avatar for tokujiros tokujiros
2
130

Featured

See All Featured
A Modern Web Designer's Workflow
Avatar for Chris Coyier chriscoyier
696
190k
Principles of Awesome APIs and How to Build Them.
Avatar for Keavy McMinn keavy
126
17k
CoffeeScript is Beautiful & I Never Want to Write Plain JavaScript Again
Avatar for Sam Stephenson sstephenson
162
15k
Embracing the Ebb and Flow
Avatar for Simon Collison colly
87
4.8k
Java REST API Framework Comparison - PWX 2021
Avatar for Matt Raible mraible
33
8.8k
How to Think Like a Performance Engineer
Avatar for Harry Roberts csswizardry
26
1.9k
Speed Design
Avatar for Sergey Chernyshev sergeychernyshev
32
1.1k
Easily Structure & Communicate Ideas using Wireframe
Avatar for Afnizar Nur Ghifari afnizarnur
194
16k
Facilitating Awesome Meetings
Avatar for Lara Hogan lara
55
6.5k
Building a Scalable Design System with Sketch
Avatar for Laura Van Doore lauravandoore
462
33k
Evolution of real-time – Irina Nazarova, EuRuKo, 2024
Avatar for Irina Nazarova irinanazarova
8
930
The Power of CSS Pseudo Elements
Avatar for Geoffrey Crofte geoffreycrofte
77
6k

Transcript

  1. Deoptimization: How YJIT Speeds Up Ruby by Slowing Down @k0kubun

    / RubyKaigi 2025

  2. @k0kubun

  3. @k0kubun Z

  4. None

  5. We’re hiring https://candidate.shopify.com/form/ruby-kaigi-2025

  6. None

  7. YJIT

  8. None

  9. https://railsatscale.com/2025-01-10-yjit-3-4-even-faster-and-more-memory-ef fi cient/

  10. None
  11. None

  12. Deoptimization

  13. None

  14. Deoptimization What if you can “slow down” Ruby at any

    time? You can speculatively optimize Ruby and invalidate it later

  15. Playing with Deoptimization Build Ruby with: ./con fi gure --enable-yjit=dev

    Run Ruby with: ruby --yjit-call-threshold=1 --yjit-dump-disasm

  16. Playing with Deoptimization

  17. None

  18. YJIT Deoptimization

  19. Code Patching

  20. None
  21. None
  22. None
  23. None

  24. Rewrite

  25. Rewrite Jump

  26. Global Invalidation

  27. None
  28. None
  29. None

  30. Ruby 3.4’s New YJIT Deoptimization

  31. Invalidation on Escaped Locals

  32. ?

  33. None
  34. None

  35. Invalidation on Singleton Classes

  36. None
  37. None
  38. None
  39. None

  40. Singleton Class Invalidation

  41. Lazy Frame Push

  42. None
  43. None
  44. None

  45. Lazy Frame Push

  46. None
  47. None
  48. None
  49. None

  50. YJIT-only Ruby Methods

  51. Array#each

  52. None
  53. None
  54. None
  55. None
  56. None
  57. None
  58. None

  59. Primitive.attr! :c_trace

  60. Conclusion Deoptimization enables speculative optimizations with lazy invalidation Ruby 3.4

    YJIT optimizes method calls and local variables using deoptimization