How to Write Garbage Code’ (by Linus Torvalds

🧠 Core Message: Optimize for Cognitive Load

Linus Torvalds harshly criticized a pull request for adding a helper function that made code less readable, not more. His main point? Code should be obvious and self-contained, not abstracted to the point of confusion.

“If you write (a << 16) + b, you know what it does. If you write make_u32_from_two_u16(a, b), you don’t.”

🧩 Key Takeaways

1. PRY > DRY (Please Repeat Yourself)

• Duplication isn’t always bad.

• Repeating simple logic can reduce mental overhead.

• Abstracting everything into helpers increases “micro-context switches.”

2. Cognitive Load Matters

• Every helper function, file jump, or abstraction costs brainpower.

• Humans and LLMs have limited working memory — fewer “chunks” = better clarity.

3. Locality of Reference

• Keep related logic close together.

• Easier for humans and AI tools to understand and refactor.

4. Premature Optimization Is Costly

• With modern IDEs and LLMs, refactoring is cheap.

• Don’t abstract early — optimize for clarity first.

5. Tone Matters

• Linus’s technical critique was valid, but his delivery was harsh.

• The author reminds us: “It doesn’t cost anything to be nice.”

💡 Final Thought

Clean code isn’t just about elegance — it’s about reducing friction for future readers. Sometimes, repeating yourself is the kindest thing you can do for your teammates (and your future self).