Reconciling application power control and operating systems for optimal power and performance

Abstract

In the age of dark silicon on-chip power control is a necessity. Upcoming and state of the art embedded- and cloud computer system-on-chips (SoCs) already provide interfaces for fine grained power control. Sometimes both: core- and interconnect-voltage and frequency can be scaled for example. To further reduce power consumption SoCs often have specialized accelerators. Due to the rising specialization of hard- and software general purpose operating systems require changes to exploit the power saving opportunities provided by the hardware. However, they lack detailed hardware- and application-level-information. Application-level power control in turn is still very uncommon and difficult to realize. Now a days vendors of mobile devices are forced to tweak and patch system-level software to enhance the power efficiency of each individual product. This manual process is time consuming and must be re-iterated for each new product. In this paper we explore the opportunities and challenges of automatic application- level power control using compilers.