Linus Torvalds uses LLM to speed up Linux kernel folio lookup

The new logic identifies folios that are frequently accessed, postpones their release until after a read‑copy‑update (RCU) grace period, and then performs both the lookup and the actual data reads inside the RCU‑protected region. This eliminates the need for reference‑counting on the fast path, allowing the kernel to read data without taking locks. In a read‑heavy benchmark the modification delivered roughly an order‑of‑magnitude speedup compared with the previous implementation.

A code review has already uncovered a race condition in the changes, so additional testing and fixes will be required before the patches can be merged into the mainline kernel.