Persistent Memory Objects: Fast and Easy Crash Consistency for Persistent Memory

TL;DR

This paper introduces Persistent Memory Objects (PMOs), a crash-consistent abstraction for persistent memory that retains the POSIX interface and simplifies crash consistency management with minimal overhead.

Contribution

We design and implement PMOs, enabling crash consistency in persistent memory while maintaining POSIX compatibility, and introduce psync for simplified durability points.

Findings

PMOs achieve crash consistency with approximately 25% overhead.

Our design speeds up performance by 1.67x to 3x over NOVA-Fortis.

The approach simplifies crash consistency management for persistent memory.

Abstract

DIMM-compatible persistent memory unites memory and storage. Prior works utilize persistent memory either by combining the filesystem with direct access on memory mapped files or by managing it as a collection of objects while abolishing the POSIX abstraction. In contrast, we propose retaining the POSIX abstraction and extending it to provide support for persistent memory, using Persistent Memory Objects (PMOs). In this work, we design and implement PMOs, a crash-consistent abstraction for managing persistent memory. We introduce psync, a single system call, that a programmer can use to specify crash consistency points in their code, without needing to orchestrate durability explicitly. When rendering data crash consistent, our design incurs a overhead of $\approx 25\%$ and $\approx 21\%$ for parallel workloads and FileBench, respectively, compared to a system without crash consistency. Compared to NOVA-Fortis, our design provides a speedup of $\approx 1.67\times$ and $\approx 3\times$ for the two set of benchmarks, respectively.