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

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

Sponsored · SiteGround - Reliable hosting with speed, security, and support you can count on. →
Avatar for Takashi Kokubun Takashi Kokubun
April 16, 2025
Programming
4.8k
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
3.8k
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
kubernetes コンポーネント開発入門 / 新卒N年目の勉強会&交流会！〜〇〇への誘い〜 #n_study
Avatar for mazrean mazrean
0
160
20260828_品質と開発生産性を両立させる、AI時代のE2Eテストの考え方
Avatar for MagicPod magicpod
0
140
「つくるAI」だけではバグは見つからない　～テストに必要な「見つけるAI」を分離させる戦略～
Avatar for Masahiko Funaki(舟木 将彦) mfunaki
0
230
이 함수, 실패하면 어떻게 되나요? null부터 Rich Errors까지, Kotlin 에러 처리 15년
Avatar for TaeHee Lee haeti2
0
130
初心者DevRelとして参加者だった私が、DevRel Talks!#2に登壇するまでにしてきたこと
Avatar for Rai sokohirai
0
330
新人はどこまで自力でやり、どこからAIに頼るべきか／エンジニア育成に向き合う_先輩たちの悩みと知見共有会
Avatar for TOPPAN ict toppan_digital_dev
1
560
AI時代に学ぶ 好きなルール 嫌いなルール Linter編
Avatar for Shota Nemoto shorty5121
0
830
新卒PdEのリアル
Avatar for ryu ryu1013
1
390
AIエージェント時代のコードレビューを設計する
Avatar for nogu nogu66
6
2.5k
AI に Inclusive UI を書かせよう — Design Rules Skill で Compose UI を作り直す
Avatar for テオリア・テクノロジーズ theoriatec2024
1
440
go-spidermonkeyでAIエージェントのCode Modeを実装する
Avatar for syumai syumai
3
1.5k
Claude Codeを組織的に動かして月400PRを実現した話
Avatar for happy_ryo happy_ryo
0
250

Featured

See All Featured
Impact Scores and Hybrid Strategies: The future of link building
Avatar for Tamara Novitovic tamaranovitovic
0
430
How to audit for AI Accessibility on your Front & Back End
Avatar for davetheseo davetheseo
0
520
Agile Actions for Facilitating Distributed Teams - ADO2019
Avatar for Mark Kilby mkilby
0
270
How To Stay Up To Date on Web Technology
Avatar for Chris Coyier chriscoyier
790
250k
Designing Powerful Visuals for Engaging Learning
Avatar for Mike Taylor tmiket
1
530
"I'm Feeling Lucky" - Building Great Search Experiences for Today's Users (#IAC19)
Avatar for Dan Newman danielanewman
230
23k
Bioeconomy Workshop: Dr. Julius Ecuru, Opportunities for a Bioeconomy in West Africa
Avatar for AKADEMIYA2063 akademiya2063
PRO
1
340
The SEO Collaboration Effect
Avatar for Kristina Bergwall kristinabergwall1
1
550
Skip the Path - Find Your Career Trail
Avatar for Mark Kilby mkilby
1
220
Navigating Weather and Climate Data
Avatar for Ryan Abernathey rabernat
0
510
Ethics towards AI in product and experience design
Avatar for Skipper Chong Warson skipperchong
2
360
Heart Work Chapter 1 - Part 1
Avatar for Lake Fama lfama
PRO
8
36k

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