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
3.4k

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
ZJIT: Building a New JIT Compiler for Ruby / REBASE 2025
Avatar for Takashi Kokubun k0kubun
0
18
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
490
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
840

Other Decks in Programming

See All in Programming
Webサーバーサイド言語としてのRustについて
Avatar for kaza kouyuume
1
5k
CSC509 Lecture 09
Avatar for Javier Gonzalez-Sanchez javiergs
PRO
0
280
釣り地図SNSにおける有料機能の実装
Avatar for nokonoko1203 nokonoko1203
0
200
CSC509 Lecture 08
Avatar for Javier Gonzalez-Sanchez javiergs
PRO
0
270
CSC305 Lecture 13
Avatar for Javier Gonzalez-Sanchez javiergs
PRO
0
340
Reactive Thinking with Signals and the Resource API
Avatar for Manfred Steyer manfredsteyer
PRO
0
120
Inside of Swift Export
Avatar for giginet giginet
PRO
1
300
Towards Transactional Buffering of CDC Events @ Flink Forward 2025 Barcelona Spain
Avatar for Hans-Peter Grahsl hpgrahsl
0
120
CSC509 Lecture 10
Avatar for Javier Gonzalez-Sanchez javiergs
PRO
0
160
Node-REDのノードの開発・活用事例とコミュニティとの関わり(Node-RED Con Nagoya 2025)
Avatar for 404background 404background
0
110
data-viz-talk-cz-2025
Avatar for Leonardo Collado-Torres lcolladotor
0
110
20251016_Rails News ～Rails 8.1の足音を聴く～
Avatar for Masato Mori morimorihoge
3
910

Featured

See All Featured
The Web Performance Landscape in 2024 [PerfNow 2024]
Avatar for Tammy Everts tammyeverts
10
900
Thoughts on Productivity
Avatar for Jon Yablonski jonyablonski
72
4.9k
Building Better People: How to give real-time feedback that sticks.
Avatar for Will Jessup wjessup
370
20k
Why Our Code Smells
Avatar for Brandon Keepers bkeepers
PRO
340
57k
BBQ
Avatar for Matthew Crist matthewcrist
89
9.9k
Typedesign – Prime Four
Avatar for Hannes Fritz hannesfritz
42
2.8k
実際に使うSQLの書き方 徹底解説 / pgcon21j-tutorial
Avatar for soudai sone soudai
PRO
192
56k
GraphQLの誤解/rethinking-graphql
Avatar for sonatard sonatard
73
11k
A Tale of Four Properties
Avatar for Chris Coyier chriscoyier
161
23k
個人開発の失敗を避けるイケてる考え方 / tips for indie hackers
Avatar for panda_program panda_program
116
20k
GitHub's CSS Performance
Avatar for Jon Rohan jonrohan
1032
470k
It's Worth the Effort
Avatar for 3n 3n
187
28k

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