Feasibility Analysis of On-Line DVS Algorithms for Scheduling Arbitrary Event Streams

Performance boosting of modern computing systems has been constrained by the significant chip/circuit power dissipation. Dynamic voltage scaling (DVS) has been applied in the past decade for reducing the energy consumption by dynamically changing the supply voltage. On-line scheduling algorithms for DVS systems usually guarantee the real-time constraints of the system based on the condition that they can select any system speed that is sufficiently high to allow processing of all events within their deadlines. However, practical systems have a maximum available system speed and the feasibility of using on-line DVS algorithms needs to be verified during design time, i.e., they will never require during runtime a speed higher than the maximum available. This paper presents feasibility analysis of two on-line DVS algorithms that can compute in advance an upper bound on the system speed that these algorithms may require given that there is a single input event stream described by the worst-case event arrivals in interval domain. Moreover, we also present new results on the competitive ratios of the resulting schedules for energy consumption minimization with comparison to the off-line optimal solutions to show the effectiveness of the two algorithms. At the end, the performance of the different algorithms is evaluated.