JetsonLEAP: a Framework to Measure Power on a Heterogeneous System-on-a-Chip Device

摘要

Computer science marches towards energy-aware practices. This trend impactsnot only the design of computer architectures, but also the design of programs.However, developers still lack affordable and accurate technology to measureenergy consumption in computing systems. The goal of this paper is to mitigatesuch problem. To this end, we introduce JetsonLEAP, a framework that supportsthe implementation of energy-aware programs. JetsonLEAP consists of an embeddedhardware, in our case, the Nvidia Tegra TK1 System-on-a-chip device, a circuitto control the flow of energy, of our own design, plus a library to instrumentprogram parts. We discuss two different circuit setups. The most precise setuplets us reliably measure the energy spent by 225,000 instructions, the leastprecise, although more affordable setup, gives us a window of 975,000instructions. To probe the precision of our system, we use it in tandem with ahigh-precision, high-cost acquisition system, and show that results do notdiffer in any significant way from those that we get using our simplerapparatus. Our entire infrastructure - board, power meter and both circuits -can be reproduced with about $500.00. To demonstrate the efficacy of ourframework, we have used it to measure the energy consumed by programs runningon ARM cores, on the GPU, and on a remote server. Furthermore, we have studiedthe impact of OpenACC directives on the energy efficiency of high-performanceapplications.