GoKawiilLinux kernel developers debate memory overhead of page tables under heavy mapping
The piece traces a long-running kernel design discussion about page tables, starting from Linus Torvalds' 2003 defense of multi-level tree-based page tables over hashed tables for TLB efficiency, and his 1997 thesis noting memory efficiency as a secondary concern. It then describes a 2020 patch from Shakeel Butt adding a page-table usage metric to memory.stat, prompted by cases like zero-copy userspace network drivers where page tables consume unusually large amounts of memory, challenging Roman Gushchin's assumption that page tables are negligible relative to mapped memory.