Ready Queue Optimization Research in Task Scheduling
Zhenyu Yin · Jisuanji fangzhen · 2006
Most of embedded real-time systems only equip limited necessary resources so the extra overheads of preemptions among tasks debase the performance of systems significantly.Through scheduling process analysis of periodic task,the waiting limit formula of each task in ready queue was obtained while guarantees its deadline.In addition,some properties,such as final preempting time was deduced and the necessary condition of periodic tasks preempting behavior was described quantitatively.Based on them,a micro scheduling preemption model for periodic tasks in ready queue was put forward,which decreased the number of preemptions and optimized system performance through changing the preempting sequences.The simulation results of the case study show that the model can not only decrease the number of preemptions effectively but also improve the processor utilization for static priority scheduling algorithm such as rate monotonic scheduling.