P-INSPECT: Architectural Support for Programmable Non-Volatile Memory Frameworks

Apostolos Kokolis, Thomas Shull, Jian Huang, Josep Torrellas

Abstract: The availability of user-friendly programming frameworks is key to the success of Non-Volatile Memory (NVM). Unfortunately, most current NVM frameworks rely heavily on user intervention to mark persistent objects and even persistent writes. This not only complicates NVM programming, but also introduces potential bugs. To address these issues, researchers have proposed Persistence by Reachability frameworks, which require minimal user intervention. However, these frameworks are slow because their runtimes have to perform checks at program load/store operations, and move data structures between DRAM and NVM during program execution. In this paper, we introduce P-inspect, a novel hardware architecture targeted to speeding up persistence by reachability NVM programming frameworks. P-inspect uses bloom-filter hardware to perform various checks in a transparent and efficient manner. It also provides hardware for low-overhead persistent writes. Our simulation-based evaluation running a state-of-the-art persistence by reachability framework shows that P-inspect retains programmability and eliminates most of the overhead. We use real-world applications to demonstrate that, on average, P-inspect reduces an application's number of executed instructions by 26% and the execution time by 16%-delivering similar performance to an ideal runtime that has no persistence by reachability overhead.