Battery-Aware Variable Voltage Scheduling on Real-Time Multiprocessor Platforms

In battery-operated portable devices, battery lifetime maximization is one of the most important design goals. This paper addresses the problem of variable voltage scheduling on battery-powered multiprocessor distributed systems, with the goal of shaping the discharge current profile to extend battery lifetime. A critical-path based battery-aware task scheduling (CPbBATS) algorithm is proposed to optimize the total load current profile (LCP) as a whole via scaling the voltage of the tasks on critical paths. The CPbBATS has a novel flow to improve the computation efficiency. Experiments on hundreds of task graphs with 10 to 100 tasks show that, compared with traditional algorithm, the CPbBATS achieved 3.3%-6.1% reduction on apparent charge lost a, 3.6%-8.3% reduction on actual charge lost Q, and average 31.99% reduction on the CPU runtime.