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
4.7k
2

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

https://rubykaigi.org/2025

Avatar for Takashi Kokubun

Takashi Kokubun

April 16, 2025

More Decks by Takashi Kokubun

See All by Takashi Kokubun
Lightning-Fast Method Calls with Ruby 4.1 ZJIT / RubyKaigi 2026
Avatar for Takashi Kokubun k0kubun
3
3.7k
一度始めたらやめられない開発効率向上術 / Findy あなたのdotfilesを教えて！
Avatar for Takashi Kokubun k0kubun
4
3.2k
ZJIT: The Ruby 4 JIT Compiler / Ruby Release 30th Anniversary Party
Avatar for Takashi Kokubun k0kubun
1
560
ZJIT: The Future of Ruby Performance / San Francisco Ruby Conference 2025
Avatar for Takashi Kokubun k0kubun
1
150
ZJIT: Building a New JIT Compiler for Ruby / REBASE 2025
Avatar for Takashi Kokubun k0kubun
0
160
YJIT Makes Rails 1.7x faster / RubyKaigi 2024
Avatar for Takashi Kokubun k0kubun
7
16k
Ruby JIT Hacking Guide / RubyKaigi 2023
Avatar for Takashi Kokubun k0kubun
2
11k
YJIT: Dive into Ruby's JIT compiler written in Rust / Rust.Tokyo 2022
Avatar for Takashi Kokubun k0kubun
2
2.4k
Towards Ruby 4 JIT / RubyKaigi 2022
Avatar for Takashi Kokubun k0kubun
3
12k

Other Decks in Programming

See All in Programming
komatsuna「分散システムにおけるバグ分析手法」
Avatar for こまつな komatsunaqa
0
280
Japan Community Day at Kubecon + CloudNativeCon Japan 2026: Learning Container Privilege Control by Building My Own Low-Level Container Runtime
Avatar for ternbusty ternbusty
1
170
AIと壁打ちしながら進めるコスト管理
Avatar for Ryoma Fujiwara fufuhu
2
1.8k
言葉の格闘技のススメ～紙とペンと言葉から始める、キャリアの描き方～
Avatar for 進捗ゼミ progresscicada
2
190
Go を使い始めて 2 ヶ月の学び / My first two months with Go
Avatar for Daisuke Garaike contour_gara
0
390
PyConJP2026_wat_Python × Signal Processing: How to Draw Pictures with Sound Using Spectrogram Art
Avatar for wat wat
0
570
Deep dive into the select statement (GopherCon UK)
Avatar for Jesús Espino jespino
0
150
生成AIで帳票OCRが「簡単に」作れる時代になった？
Avatar for Shohei Kondo kon_shou
0
1.2k
仕様駆動開発へのトライを機に チームに適合する手法を模索し続けている話
Avatar for freee freee
PRO
0
640
引き算の組織 ― アウトカムとAIに全振りするために辞めたこと ― / Organization by Subtraction
Avatar for ヤマモトヒロキ hirokiyamamoto14
PRO
0
310
T3DD26: From RAGs to Riches
Avatar for Martin Helmich martinhelmich
0
110
プロポーザルを書いてもらう
Avatar for pvcresin pvcresin
0
590

Featured

See All Featured
AI: The stuff that nobody shows you
Avatar for John Nunemaker jnunemaker
PRO
9
950
Principles of Awesome APIs and How to Build Them.
Avatar for Keavy McMinn keavy
128
18k
The Invisible Side of Design
Avatar for Vitaly Friedman smashingmag
301
52k
The #1 spot is gone: here's how to win anyway
Avatar for Tamara Novitovic tamaranovitovic
3
1.1k
Practical Orchestrator
Avatar for Shlomi Noach shlominoach
191
12k
Code Review Best Practice
Avatar for Trisha Gee trishagee
74
20k
Mozcon NYC 2025: Stop Losing SEO Traffic
Avatar for Sam Torres samtorres
1
510
Taking LLMs out of the black box: A practical guide to human-in-the-loop distillation
Avatar for Ines Montani inesmontani
PRO
3
2.4k
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
123
22k
[RailsConf 2023 Opening Keynote] The Magic of Rails
Avatar for Eileen M. Uchitelle eileencodes
31
10k
Visualizing Your Data: Incorporating Mongo into Loggly Infrastructure
Avatar for mongodb mongodb
49
10k
Dominate Local Search Results - an insider guide to GBP, reviews, and Local SEO
Avatar for Greg Gifford greggifford
PRO
0
310

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