设备级OS中任务调度的IO抖动优化策略

 为了减小任务调度产生的抖动对设备级操作系统的稳定性和可靠性的影响,提出了一种带有抢占阈值的任务分割模型RJPS.根据抢占阈值对任务调度的抖动与延迟的影响及该模型下任务可调度性的分析,分别设计了基于固定优先级调度和动态优先级调度策略的最小阈值分配算法.仿真结果表明,该模型可以在保证任务集可调度的前提下明显减少任务的IO抖动.

Optimization of IO Jitter in the Device-Level OS Scheduling

In order to reduce the influence of the jitter of hard real-time task caused by scheduling to the stability and reliability of device-level operation system,a model with preemption segment threshold -RJPS is presented.According to the effect on jitter and latency brought by threshold and the analysis of the scheduling on this model,minimum threshold assigned algorithms are designed,which are applied for fixed-priority scheduling and fixed-priority scheduling separately.It is shown by simulation experiment that the threshold segmentation scheduling model can effectively reduce the IO jitter of tasks caused by scheduler in the typical scheduling algorithm.