Robust aperiodic scheduling under dynamic priority systems
Robust aperiodic scheduling under dynamic priority systems
复制标题
动态优先级系统下的鲁棒非周期调度
DOI：
10.1109/real.1995.495211
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发表时间：
1995
期刊：
影响因子：
--
通讯作者：
F. Sensini
中科院分区：
文献类型：
--
作者：
M. Spuri;G. Buttazzo;F. Sensini
当硬周期任务和硬非周期任务在同一系统中联合调度时，处理器工作负载可能会根据非周期请求的到达时间而变化。为了保证周期性任务集的可调度性，在过载情况下必须拒绝一些非周期性任务。在本文中，我们提出了一种技术，在过载条件下，为具有动态优先级的系统中的周期性和非周期性任务的联合调度增加鲁棒性。我们的技术基于非周期性服务器，称为总带宽服务器，在之前的工作中已经证明是有效的。在这里，该算法首先被扩展以有效地处理固定的非周期性任务，然后与强大的保证机制集成，该机制允许在瞬态过载的情况下实现优雅的降级。广泛的模拟表明，所提出的新算法在所有工作负载条件下都是有效的。
When hard periodic and firm aperiodic tasks are jointly scheduled in the same system, the processor workload can vary according to the arrival times of aperiodic requests. In order to guarantee the schedulability of the periodic task set, in overload conditions some aperiodic tasks must be rejected. In this paper we propose a technique that, in overload conditions, adds robustness to the joint scheduling of periodic and aperiodic tasks in systems with dynamic priorities. Our technique is based on an aperiodic server, called total bandwidth server, already proven effective in a previous work. Here the algorithm is first extended to efficiently handle firm aperiodic tasks and then integrated with a robust guarantee mechanism that allows to achieve graceful degradation in case of transient overloads. Extensive simulations show that the proposed new algorithm is effective in all workload conditions.