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
1
1.9k

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
9.9k
YJIT: Dive into Ruby's JIT compiler written in Rust / Rust.Tokyo 2022
Avatar for Takashi Kokubun k0kubun
1
2.1k
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
450
Why Ruby's JIT was slow / RubyKaigi Takeout 2021
Avatar for Takashi Kokubun k0kubun
3
1.9k
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
810
Ruby 3.0 JIT on Rails
Avatar for Takashi Kokubun k0kubun
9
9.3k

Other Decks in Programming

See All in Programming
The Implementations of Advanced LR Parser Algorithm
Avatar for Junichi Kobayashi junk0612
1
1.3k
一緒に働きたくなるプログラマの思想 #QiitaConference
Avatar for mu_zaru mu_zaru
78
20k
今話題のMCPサーバーをFastAPIでサッと作ってみた
Avatar for Yuuki Shimizu yuukis
0
110
プロフェッショナルとしての成長「問題の深掘り」が導く真のスキルアップ / issue-analysis-and-skill-up
Avatar for MinoDriven minodriven
8
1.9k
Носок на сок
Avatar for Bo0oM bo0om
0
1.1k
Instrumentsを使用した アプリのパフォーマンス向上方法
Avatar for hinakko hinakko
0
230
Bedrock×MCPで社内ブログ執筆文化を育てたい！
Avatar for Har1101 har1101
7
1.4k
DevOpsDaysTokyo2025社内副業で他部門へ_越境_して見えた価値再定義最大1か月のリードタイムを10分に短縮したDevOps実践.pdf
Avatar for susumutomita susumutomita
0
110
iOSアプリで測る！名古屋駅までの 方向と距離
Avatar for Ryu-nakayama ryunakayama
0
150
エンジニアが挑む、限界までの越境
Avatar for Nealle nealle
1
310
AIコーディングの理想と現実
Avatar for Tomohisa Takaoka tomohisa
35
37k
2ヶ月で生産性2倍、お買い物アプリ「カウシェ」4チーム同時改善の取り組み
Avatar for ike ike002jp
1
110

Featured

See All Featured
Helping Users Find Their Own Way: Creating Modern Search Experiences
Avatar for Dan Newman danielanewman
29
2.6k
Done Done
Avatar for chrislema chrislema
184
16k
Documentation Writing (for coders)
Avatar for Carmen Chung carmenintech
69
4.7k
Become a Pro
Avatar for Speaker Deck speakerdeck
PRO
28
5.3k
The Art of Delivering Value - GDevCon NA Keynote
Avatar for David Neal reverentgeek
14
1.4k
Refactoring Trust on Your Teams (GOTO; Chicago 2020)
Avatar for Rebecca Miller-Webster rmw
34
2.9k
ReactJS: Keep Simple. Everything can be a component!
Avatar for Pedro Nauck pedronauck
667
120k
Let's Do A Bunch of Simple Stuff to Make Websites Faster
Avatar for Chris Coyier chriscoyier
507
140k
BBQ
Avatar for Matthew Crist matthewcrist
88
9.6k
Building an army of robots
Avatar for Kyle Neath kneath
305
45k
Imperfection Machines: The Place of Print at Facebook
Avatar for Scott Boms scottboms
267
13k
Bash Introduction
Avatar for André Augusto Costa Santos 62gerente
611
210k

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