关键词: 调度 优先级 特征参数 实时

Abstract:

This paper proposes a task priority design method based on four feature parameters：task value, remaining execution time, slack time and arrival time,and makes the task priority change accordingly with the change of the task＇s degree of urgency and the percentage of the completion of the task. A dyn namic preemptive scheduling algorithm is presented based on the new task priority design method, which is called VRSAF. The simulation results show that the scheduling performance of VRSAF is close to EDF algorithms in light load situation. And in overload situation, the performance of scheduling is hig  her than the HVF algorithm. The overall activation performance is high, especially it can degrade gracefully under the overload situation.

Key words: scheduling, priority, characteristic parameters, real-time