基于动态抢占阈值的LSF调度算法  

Least Slack First Schedule Algorithm Based on Dynamic Preemption Threshold

作　　者：任小西[1] 赵公怡[1] 

机构地区：[1]湖南大学信息科学与工程学院,长沙410082

出　　处：《计算机工程》2012年第4期275-277,280,共4页Computer Engineering

基　　金：中央高校基本科研业务费专项基金资助项目(0148)

摘　　要：在最小空闲时间优先(LSF)调度算法中,当任务集中有多个任务的优先级相同或相近时,过多的上下文切换会产生"颠簸"现象,从而大幅增加系统开销。为此,结合LSF算法的特点,通过设计合理的动态抢占阈值,提出一种改进的调度算法DPTLSF。仿真结果表明,改进的算法能够大幅减少"颠簸"现象的发生,降低任务集的截止期错失率。In Least Slack First（LSF） schedule algorithm, when there are multiple tasks which have the same or similar task priority, too much context switch resulting ＂bump＂ phenomenon that will greatly increase the system overhead. Based on preemption threshold, combined with the characteristics of LSF algorithm, through the rational design of dynamic preemption threshold, this paper proposes an improved algorithm named DPTLSF. Simulation results show that the improved algorithm can effectively reduce the ＂bumps＂ from occurring and reduce the missed deadline percentage of task set.

关 键 词：实时调度 上下文切换 颠簸 抢占阈值 最小空闲时间优先 

分 类 号：TP316[自动化与计算机技术—计算机软件与理论]