Torvalds used Claude Code to fix Linux page cache, reviewers found a race

Linus Torvalds used Anthropic's Claude Code to fix a page-cache reference-counting bottleneck that developers had struggled with for over two years. The 10-patch series delivered a 23-fold throughput gain in a synthetic benchmark, but reviewers found a race condition and raised memory reclamation concerns.

• Throughput on Ryzen Threadripper rose from 13.3M to 304M reads per second
• On a Core i7-8565U laptop, eight threads went from 10M to 33M reads per second
• Reviewers found a race in filemap_read_rcu_batch() and questioned the PG_rcu_free flag
• Torvalds handed further development to Kiryl Shutsemau