Merlin: Improving Page Prefetching via Online Reinforcement Learning
Yingying Liu, Junzhe Li, Junzhou Fang, Chenxiong Qian · 2025
While the operating system (OS) page swapping mechanism enables memory oversubscription, memory-intensive workloads suffer significant performance degradation when the main memory cannot accommodate their entire working sets. To hide the swapping overhead, prefetching techniques predict future data accesses and proactively load necessary contents from slower backing storage into the main memory. However, existing OS prefetching algorithms rely on predefined rules to analyze page access patterns, which are not adaptive to changing workloads and fail to align prefetching policies with system status.