Linux 7.4 merge window receives 539 memory management patches

Andrew Morton has released a significant set of memory management (MM) patches for the Linux 7.4 merge window. This cycle consists of 539 patches with a 76% review rate, covering a wide range of improvements. Key updates include expanded capabilities for the DAMON data access monitoring framework, performance enhancements for Multi-Gen LRU (MGLRU), and ongoing transitions toward using folios within the kernel's memory subsystem.

Technical highlights of the MM updates

• DAMON Enhancements: The Data Access MONitor (DAMON) now supports access monitoring for HugeTLB-backed memory and introduces an auto-tuned mechanism for collapsing huge pages.
• Latency Reduction: Reading /proc/PID/smaps_rollup now utilizes per-VMA locks where applicable, significantly reducing latency when other threads are modifying mappings.
• Performance Optimizations: Improvements have been made to the Multi-Gen LRU (MGLRU) code and the initialization of zone-device struct pages to eliminate redundant operations.
• Folio Migration: The kernel continues its transition toward folios, including new page-to-folio conversions within swap I/O processes.

Why it matters

These updates will improve system responsiveness and memory efficiency across various workloads, particularly for high-performance computing and database tasks. The continued refinement of DAMON and MGLRU provides developers and sysadmins with better tools for monitoring and managing complex memory patterns.