Persistent Memory Objects on the Cheap
Derrick Greenspan, Naveed Ul Mustafa, Jongouk Choi, Mark A. Heinrich, Yan Solihin · 2025
Persistent Memory Objects (PMOs) are the state-of-the-art OS-based approach for persistent memory (PM) management.Recent PMO designs have limited performance due to the properties of the PM substrate.To address this challenge, this paper introduces LPMO, or lightweight PMOs, that enables two key performance optimization techniques: softwarebased DRAM caching and prediction.First, through DRAM caching, LPMO moves reads/writes to a faster medium, while retaining crash consistency.Second, LPMO introduces softwarebased predecryption to predict when pages might be used and decrypt them ahead of time.Our evaluation shows that software-based DRAM Caching and software-based predecryption with LPMO can improve the performance of a PMO system by up to 1.25× compared to the prior state-of-the-art implementations when using LPMO locally.When bundled with a stream predictor, the improvement reaches 1.81×, depending on the workload.To further demonstrate the flexibility and performance benefits of our LPMO design, we evaluated our solution in a CXL memory system and introduce a CXL memory hierarchy that our LPMO system can configure.In such a CXL