Pinpoint the Joules: Unifying Runtime-Support for Energy Measurements on Heterogeneous Systems

For the design and operation of today's computer systems, power and energy requirements are highest priorities. Unlike performance analyses, however, power and energy measurements of heterogeneous systems are difficult to conduct. Especially at the system-software level, performing power and energy measurements remains challenging. Yet, such measurements are essential to improve software components for low power and high energy-efficiency. In this paper, we analyze and discuss the power and energy characteristics of several heterogeneous systems with up to 20 cores (160 hardware threads) and 1 TB of main memory. For the analyzed systems, we outline challenges regarding power and energy measurements and show ways to overcome limitations (i.e., sampling constraints). To improve the current state of the art in power and energy measurements at the system-software level, we present the design and implementation of PINPOINT, an energy-profiling tool which unifies different power and energy measurement interfaces.