In-Memory Versioning (IMV)

In this letter, we propose and evaluate designs for a novel hardware-assisted data versioning system (in-memory versioning or IMV) in the context of high-performance computing. Our main novelty and advantage over recent published work is that it does not require any changes to host processor logic, instead augmenting a memory controller within memory modules. It is faster and more efficient than existing high-performance computing (HPC) checkpointing schemes and works from hours to sub-second checkpoint intervals. The main premise is to perform most operations in hardware at cache-line granularity, avoiding operating system (OS) latency and page copying bandwidth overhead. Energy is saved by keeping data movement in the memory module, compared with page granularity cross channel or cross-network copying that is currently used. For a 1-second checkpoint commit interval, we demonstrate up to 20x checkpoint performance and 70x energy savings using IMV versus page copy-on-write (COW).