一种混合优先级的防危调度算法  

Safety Schedule Algorithm Based on Mixed Priority

作　　者：万明[1] 张凤鸣[1] 樊晓光[1] 

机构地区：[1]空军工程大学工程学院,西安710038

出　　处：《计算机工程》2010年第22期254-255,258,共3页Computer Engineering

基　　金：国家部委基金资助项目

摘　　要：为增强实时系统任务过载时的防危性,提出一种混合优先级的防危调度算法,其优先级由相对截止期优先级和相对松弛度优先级组成,通过相对松弛度预测任务的可完成性,并采用完全抢占方式防止处理器资源的竞争抖动。仿真结果表明,该算法可充分利用处理器资源,能在发生瞬时过载时有效降低任务的截止期错失率。To improve the safety of real-time system at transient overload, a schedule algorithm based on mixed priority is proposed. The priority of the algorithm consists of relative deadline priority and relative slack priority. With relative slack, whether tasks will miss deadline can be predicted. Through the complete CPU preemption, frequent context switch can be avoided. Simulation results show that the presented algorithm improves the efficiency of task schedule and effectively decreases the Missed Deadline Percentage（MDP） at transient overload.

关 键 词：实时系统 防危调度 调度算法 任务优先级 截止期错失率 

分 类 号：TP391[自动化与计算机技术—计算机应用技术]