ViPZonE: OS-level memory variability-driven physical address zoning for energy savings

Abstract

ITRS predicts that over the next decade, hardware power variation will increase at alarming rates. As a result, designers must build software that can adapt to and exploit these variations to reduce power consumption and improve system performance. This paper presents ViPZonE, a system-level solution that opportunistically exploits DRAM power variation through physical address zoning. ViPZonE is composed of a variability-aware software stack that allows developers to indicate to the OS the expected dominant usage patterns (write or read) as well as level of utilization (high, medium, or low) through high-level APIs. ViPZonE's variability-aware page allocator, implemented in the Linux kernel, is responsible for interpreting these high-level requests for memory and transparently mapping them to physical address zones with different power consumption. Our experimental results across various configurations running PAR-SEC workloads show an average of 13.1% memory power consumption savings at the cost of a modest 1.03% increase in execution time over a typical Linux virtual memory allocator.