BattOr: Plug-and-debug energy debugging for applications on smartphones and laptops Stanford CS Tech Report

As battery-operated devices like smartphones and laptops have become the norm for users, a critical feature of applications is to ensure low power consumption. Yet, surprisingly, energy bugs remain difficult to find and fix because developers lack the tools to allow them to quickly and authoritatively reason about how much power the various components of their applications consume. To address this need, we present BattOr, a power monitoring system consisting of (1) a hardware component that collects accurate measurements without requiring soldering (developers can plug-and-debug), and (2) a software component that precisely synchronizes these measurements with low-level system events already captured by OSes. A distinguishing feature of BattOr is that it is compatible with existing, continuous integration testing systems, and has been evaluated in production environments. We present case studies, including one in which BattOr was used to find and fix a long-lived energy bug that had resulted in a 38% increase in power consumption of Chrome on OS X as compared to Safari.