Compiler-Directed Whole-System Persistence

Nonvolatile memory (NVM) technologies have gained increasing attention thanks to their density and durability benefits. However, leveraging NVM can cause a crash consistency issue. For example, if a younger store is evicted (persisted) to NVM from volatile caches before an older one and power failure occurs in between, it might be impossible to correctly resume the interrupted program in the wake of the failure. Traditionally, addressing this issue involves expensive persist barriers for enforcing the original store order, which not only incurs a high run-time overhead but also places a significant burden on users due to the difficulty of persistent programming. To this end, this paper presents cWSP, compiler/architecture codesign for lightweight yet performant whole-system persistence (WSP). In particular, cWSP compiler partitions not only user applications but also OS and runtime libraries into a series of recoverable regions (epochs), thus enabling persistence and crash consistency for the entire software stack. To achieve high-performance crash consistency, cWSP leverages advanced compiler optimizations for checkpointing a minimal set of registers and proposes simple hardware support for expediting data persistence on the cheap. Experimental results with 37 applications from SPEC CPU2006/2017, DOE Mini-apps, SPLASH3, WHISPER, and STAMP, show that cWSP incurs an average runtime overhead of $6 \%$, outperforming the state-of-the-art work with a significant margin.