# Linus Torvalds Uses AI to Rewrite Linux Kernel

> Linus Torvalds admits AI wrote Linux kernel patch after 90% AI hype claim.
- Title: Linus Torvalds Uses AI to Rewrite Linux Kernel | Shortify
- Summary: Linus Torvalds admits AI wrote Linux kernel patch after 90% AI hype claim. Linus Torvalds used AI coding tool to rewrite Linux kernel page cache, showing…
- Keywords: linus torvalds, linux kernel, claude code, page cache patch, rcu read-side critical section, ai code generation, kernel patch, startups, business, Linus, Torvalds, Uses
- Source: Startup Fortune — https://startupfortune.com/linus-torvalds-used-claude-code-to-rewrite-how-linux-reads-cached-files
- Published: 2026-10-12T09:21:08+00:00
- Read time: 1 min
- Topics: linus torvalds, linux kernel, claude code, page cache patch, rcu read-side critical section, ai code generation, kernel patch, startups, business
## Linus Torvalds
Linus Torvalds posted a kernel patch series on October 12.

> The code, the test programs, the review behind the list above and the first draft of this text were done with an LLM coding assistant (Claude Code) under my direction
## Patch Series
The branch is called noref-filemap-read-with-llm for improved page cache performance.

> The problem the patch solves is narrow but real
## Performance Metrics
Kernel cycles per read dropped from 2,950 to 725 with 10.4 million reads per second.

> Throughput on the same workload jumped from 9.9 to 10.4 million reads per second
## AI Code Admission
Torvalds admitted AI wrote the code under his supervision for the patch.

> The code, the test programs, the review behind the list above and the first draft of this text were done with an LLM coding assistant (Claude Code) under my direction
## AI Hype History
Torvalds previously claimed 90% of AI talk was marketing hype in October 2024.

> Back in October 2024, Torvalds said 90% of AI talk was marketing hype
## AI Code Review
Google's Sashiko AI caught 53% of kernel bugs in testing by March 2026.

> According to reporting from ITsFoss and ADTmag, the catalyst was partly Sashiko
## Tradeoff Analysis
Single-thread performance slightly slower but concurrency benefits outweighed.

> A single-thread case touching an unmapped page got slightly slower
## Key takeaway

Linus Torvalds used AI coding tool to rewrite Linux kernel page cache, showing improved performance while admitting AI wrote the code under his supervision.