Research on Persistent Memory File System Optimization

Abstract

Emerging byte-addressable non-volatile memory offers high performance like DRAM and data persistency like disks. In order to use the NVM in a reasonable manner, existing storage systems put the NVM on memory bus and design a specialized file system to take advantage of the characteristics of NVM. However, the current NVM-based file systems use the page table to provide direct access in NVM, which cause seriously performance overhead in page fault. In this paper, to address this issue, we propose a unified mapping structure based memory-mapped file system. It combines the advantages of memory page table and file data index, and uses the page table structure based data index as the unified address structure. By using this method, we can efficiently implement the mapping and release of resources, also, we can effectively reduce the overhead of page fault. By using the memory simulator, we evaluate our file system in various workloads. Evaluation results show that, our unified mapping structure based memory-mapped file system effectively improves the access performance and reduces space overhead during the accessing process.