MPFS: A Scalable User-Space Persistent Memory File System for Multiple Processes

¹¹This work was supported by the Young Scientists Fund of the National Natural Science Foundation of China under Grant 62302182.Persistent memory (PM) leveraging memory-mapped I/O(MMIO) delivers superior I/O performance, leading to the development of user-space PM file systems based on MMIO. While effective in single-process scenarios, these systems encounter challenges in multi-process environments, such as performance degradation due to repeated page faults and cross-process synchronizations, as well as a large memory footprint from duplicated paging structures. To address these problems, we propose a Multi-process PM File System (MPFS). MPFS builds a shareable page table and shares it among processes, avoiding building duplicate paging structures for distinct processes, thereby significantly reducing the software overhead and memory footprint caused by repeated page faults. MPFS further proposes a PGD-aligned (512GB) mapping method to accelerate page table sharing. Furthermore, MPFS provides a cross-process memory protection mechanism based on the PGD-aligned mapping, ensuring multi-process data reliability with negligible overheads. The experimental results show that MPFS outperforms existing user-space PM file systems by 1560% in multi-process scenarios.