The TAU Programming Languages and Systems Seminar - On the Foundations of Systems for Non-Volatile Memory

Non-volatile memory (NVM) technologies such as PCM, ReRAM and STT-RAM allow processors to directly write values to persistent storage at speeds that are significantly faster than previous durable media such as hard drives or SSDs. In recent years, many systems were proposed to help applications utilizing this memory. These systems rely on a logging subsystem, which enables operations to appear to execute atomically and facilitates recovery from failures. Writes to NVM, however, pass through a processor's memory system, which can delay and reorder them and can impair the correctness and cost of logging algorithms.

Reordering arises because of out-of-order execution in a CPU and the inter-processor cache coherence protocol. By carefully considering the properties of these reorderings, we show how to develop a logging protocol that requires only one round trip to non-volatile memory while avoiding expensive computations. This design can be extended to a persistent set (hash map) that also requires only a single round trip to non-volatile memory for insertion, updating, or deletion.

No background in Non-Volatile Memory is needed.