Earl

As system complexity grows, embedded operating systems increasingly face the challenge to adhere to various non-functional constraints, such as response times and power limits. These requirements sometimes contradict and, often, no solution satisfies all constraints under all conditions. Changes in environmental conditions, application-level requirements, and user response time expectation hence demand for system-wide adaptions to resource management. We find that process synchronization constitutes a simple yet effective leverage point to balance between timing-related and energy-related constraints. This paper presents Earl, an implementation of reconfigurable locks in Linux that enables seamless transitions between high-performance and low-power operating modes.