Rethinking PM Crash Consistency in the CXL Era

Abstract: Persistent Memory (PM) introduces new opportunities for designing crash-consistent applications without the traditional storage overheads. However, ensuring crash consistency in PM demands intricate knowledge of CPU, cache, and memory interactions. Hardware and software mechanisms have been proposed to ease this burden, but neither proved sufficient, prompting a variety of bug detection tools. With the sunset of Intel Optane comes the rise of Compute Express Link (CXL) for PM. In this position paper, we discuss the impact of CXL's disaggregated and heterogeneous nature in the development of crash-consistent PM applications, and outline three research directions: hardware primitives, persistency frameworks, and bug detection tools.