Linus Torvalds let Claude Code fix the Linux page cache. reviewers found a race (thenewstack.io)

In a notable development for the Linux kernel community, Linus Torvalds collaborated with Anthropic’s Claude Code to address a long-standing performance issue in the Linux page cache. Over a two-year struggle, Torvalds presented a series of 10 patches that achieved an impressive 23-fold improvement in throughput during synthetic benchmarks on his Ryzen Threadripper. This breakthrough was crucial as earlier attempts to fix a reference-counting bottleneck had failed, impacting cross-core load operations severely. While these revisions showed significant gains, Torvalds cautioned that actual performance in real-world scenarios might not match bench-marked results. However, the introduction of this new approach came with challenges, as reviewers quickly identified a race condition alongside concerns regarding memory reclamation. The strategy employs a new PG_rcu_free flag to enhance protection against potential data exposure during read operations, yet it has raised questions among maintainers about its efficacy and design. The ongoing discourse around the reclamation method highlights the complexities within kernel development and underscores the importance of rigorous peer review in ensuring stability and efficiency in the Linux environment. As Torvalds hands over further development to Kiryl Shutsemau, the implications of this collaboration between human developers and AI assistance could pave the way for innovative solutions in the future.