Abstract: For the Earliest-Pseudo-Deadline-First（EPDF） Pfair algorithm on multiprocessor platforms, according to the schedulable utilization bound of EPDF on M processors and utilization-based schedulability test, an improved schedulability test for EPDF has been proposed. This method can detect more tasks scheduled, which will enable less-expensive scheduling for hard real-time systems that satisfy the test and dynamic task systems where tie-breaking rules are problematic. The experimental results demonstrate that the presented schedulability test with better performance increases the amount of detected task sets.

Key words: real-time system, real-time scheduling, multiprocessor, schedulability test, schedulable utilization bound

摘要： 针对多处理器实时调度中的最早伪时限优先（EPDF） Pfair算法，分析了EPDF算法在M个处理器平台上的可调度利用率约束，根据基于利用率的充分可调度性判定，提出了一种改进的可调度性判定方法。这种方法可以得到更多的可调度任务集，从而使得满足判定的强实时系统和使用tie-breaking规则困难的动态任务系统的调度有较小的开销。实验结果表明，改进的可调度性判定方法增加了判为可调度的任务集数量，具有较好的性能。

关键词: 实时系统, 实时调度, 多处理器, 可调度性判定, 可调度利用率约束