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。
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
Abstract: 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.
Key words:
real-time schedule,
context switch,
bump,
preemption threshold,
Least Slack First(LSF)
中图分类号:
任小西, 赵公怡. 基于动态抢占阈值的LSF调度算法[J]. 计算机工程, 2012, 38(04): 275-277.
LIN Xiao-Xi, DIAO Gong-Yi. Least Slack First Schedule Algorithm Based on Dynamic Preemption Threshold[J]. Computer Engineering, 2012, 38(04): 275-277.