基于資源回收的容錯單調比率調度

【摘要】基于時間冗余的容錯實時調度算法，其可調度條件是以任務的最壞執(zhí)行時間和為任務預留容錯操作的時間為分析基礎，且任務拒絕率高，系統(tǒng)資源利用率低。該文提出的基于資源回收的容錯單調比率調度，以容錯實時調度算法FT-RM為基礎，利用任務的實際執(zhí)行時間低于最壞執(zhí)行時間的特性，收集已完成任務釋放的資源供等待任務使用，在保證系統(tǒng)容錯要求的同時，提高了任務吞吐量和系統(tǒng)資源利用率，并通過模擬實驗分析算法性能，研究了影響算法調度性能的若干因素。
關 鍵 詞 容錯; 實時系統(tǒng); 容錯單調比率調度; 資源回收

Fault-tolerant real-time scheduling algorithm through time redundancy, whose schedulability bound is based on the worst execution time of tasks and the time reserved for tasks’ fault-tolerant operation, has high rejection rate and low resource utilization. This paper presents fault-tolerant rate-monotonic scheduling with resource reclaim, based on FT-RM, to improve resource utilization and tasks throughoutput. This algorithm makes use of the attribute that the actual execution time of task is shorter than the worst execution time, to reclaim and reuse the resource released by the ended task. At last, the performance simulation and analysis of the scheduling algorithm are presented and factors that affect performance are investigated.