LosPem

Abstract

New and emerging types of Persistent Memory (PM) technologies boost the opportunity to improve the performance of storage systems. PM can unify the main memory and secondary storage by incorporating it into legacy computer systems through the memory bus. In recent years, innovative results have been presented that exploit the byte-addressability, low latency, and non-volatility of PM; these have included local PM file systems and PM systems. However, the high overhead of ensuring data consistency has limited the performance of these systems. In this article, we propose LosPem, a novel log-structured framework for persistent memory to address the performance challenge. LosPem utilizes two techniques to accomplish this. Firstly, LosPem deploys efficient hash-indexed linked lists to maintain the log contents to reduce the significant overhead of log content retrieval. Secondly, LosPem improves the transaction throughput by decoupling a transaction into two asynchronous steps and creating a write buffer on Dynamic Random Access Memory (DRAM) write buffer for processing the frequent data writes. The experimental results show that LosPem outperforms Non-volatile Memory Library (NVML), Mnemosyne and Log-structured Non-volatile Main Memory (LSNVMM) by 27%, 1.2x, and 1.0x on a read-intensive workload. On a write-intensive workload, LosPem outperforms NVML, Mnemosyne, and LSNVMM by 1.8x, 1.2x, and 34%, respectively.