国家自然科学基金(60903160, 61103046); 上海市自然科学基金(11ZR1401200)
Lopez 等学者求解出基于单调速率算法和首次适应分派策略的多处理器实时任务可调度性判定边界.该边界在所有O(m)复杂度的判定边界中是最优的.基于Bini 等学者针对单处理器提出的双曲线可调度性判定方法,给出了一种多处理器实时任务可调度性判定边界.新边界在相当数量的利用率分布下明显优于已有边界.新边界与已有边界具有相容性,所以虽然新边界无法在所有情况下超越已有边界,但在实际应用中可联合两种边界进行判定,在不增加计算复杂度的同时全面提高可调度任务集的数量.
The utilization bound for multiprocessor systems using the rate-monotonic scheduling algorithm and first fit allocation policy proposed by Lopez, et al. offers the best performance among all O(m) complexity schedulability tests. In this paper, a utilization bound is derived for the same target problem. The main difference between these two bounds lies in the technique to verify the schedulability of task sets on uniprocessors; the schedulability test here is performed based on the hyperbolic bound proposed by Bini, et al. The new bound surpasses the existing one under quite a lot parameter settings, and the combination of these two schedulability test methods, which are compatible with each other, can significantly improve the number of schedulable task sets with little extra overhead.