ProFess: A Probabilistic Hybrid Main Memory Management Framework for High Performance and Fairness

Non-Volatile Memory (NVM) technologies enable cost-effective hybrid main memories with two partitions: M1 (DRAM) and slower but larger M2 (NVM). This paper considers a flat migrating organization of hybrid memories. A challenging and open issue of managing such memories is to allocate M1 among co-running programs such that high fairness is achieved at the same time as high performance. This paper introduces ProFess: a Probabilistic hybrid main memory management Framework for high performance and fairness. It comprises: i) a Relative-Slowdown Monitor (RSM) that enables fair management by indicating which program suffers the most from competition for M1; and ii) a probabilistic Migration-Decision Mechanism (MDM) that unlocks high performance by realizing cost-benefit analysis that is individual for each pair of data blocks considered for migration. Within ProFess, RSM guides MDM towards high fairness. We show that for the multiprogrammed workloads evaluated, ProFess improves fairness by 15% (avg.; up to 29%), compared to the state-of-the-art, while outperforming it by 12% (avg.; up to 29%).