Compiler-directed power optimization of high-performance interconnection networks for load-balancing MPI applications

Abstract

Energy consumption of parallel computers has been becoming the obstruction to higher-performance systems. In this paper, we focus on power optimization of high-performance interconnection networks for MPI applications in high-performance parallel computers. Compared with the past history-based work, we propose the idea of compiler-directed power-aware on/off network links. There are some idle intervals for network links during the execution of parallel applications, at which the links still consume large amounts of energy. Using on/off network links, compiler first divides load-balancing MPI applications into the communication intervals and the computation intervals, and then inserts the on/off instruction into the applications to switch the link state. To avoid the time overhead of state switching, we use a time estimation technique to analyze the computation time, and insert the on instruction before reaching the communication intervals. Results from simulations and experiments show that the proposed compiler-directed method can reduce energy consumption of interconnection networks by 20~70%, at a loss of less than 1% network latency and performance degradation.