Memory-miser

Abstract

Main memory in clusters may dominate total system power. The resulting energy consumption increases system operating cost and the heat produced reduces reliability. Emergent memory technology will provide servers with the ability to dynamically turn-on (online) and turn-off (offline) memory devices at runtime. This technology, coupled with slack in memory demand, offers the potential for significant energy savings in clusters of servers. Enabling power-aware memory and conserving energy in clusters are non-trivial. First, power-aware memory techniques must be scalable to thousands of devices. Second, techniques must not negatively impact the performance of parallel scientific applications. Third, techniques must be transparent to the user to be practical. We propose a Memory Management Infra-Structure for Energy Reduction (Memory MISER). Memory MISER is transparent, performance-neutral, and scalable. It consists of a prototype Linux kernel that manages memory at device granularity and a userspace daemon that monitors memory demand systemically to control devices and implement energy- and performance-constrained policies. Experiments on an 8-node cluster show our control daemon reduces memory energy up to 56.8% with