From Startup Fortune · · 1m
Linus Torvalds Uses AI to Rewrite Linux Kernel
Linus Torvalds admits AI wrote Linux kernel patch after 90% AI hype claim.
In brief
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 improved performance while admitting AI wrote the code under his supervision. Originally reported by Startup Fortune.
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”
The bottom line
Linus Torvalds used AI coding tool to rewrite Linux kernel page cache, showing improved performance while admitting AI wrote the code under his supervision.
