Towards Enhanced I/O Performance of NVM File Systems

Non-volatile memory (NVM) provides bulk storage capacity, like NAND flash, while providing low latency, like DRAM, at the same time. NVM enables high-performance, reliable, and cost-effective high performance systems by providing low-latency data access and high capacity storage compared to traditional disk-based system. As NVM becomes a novel tier in the memory hierarchy, efficiently utilizing NVM I/O capability is important. In this work, we evaluate the I/O performance of NVM in three aspects: the performance change with a varying number of concurrent accesses, the performance difference between remote and local accesses, and the performance change with various access granularity. We also compare the performance of NVM file systems that handle the different I/O characteristics of NVM. Specifically, Odinfs is the state-of-the-art NVM file system that solves the performance degradation of NVM with large number of threads and remote NUMA node accesses. We further optimize Odinfs by solving the I/O performance degradation with a small number of threads. We evaluate the optimized version of Odinfs and show that the throughput of Odinfs is increased by 30.91% with four or fewer threads.