Following the trend of increasing autonomy in cyber-physical systems, parallel embedded architectures have enabled devices to better handle the large streams of data and intensive computation required by such autonomous systems. However, while the explosion of highly-parallel platforms has seen a proportional growth in the number of applications/devices that utilize these platforms, the embedded systems community's understanding of how to build time-predictable, safety-critical systems with parallel platforms has not kept pace. As a well-motivated but challenging parallel scheduling model, gang scheduling requires all parallel threads of each parallel task to simultaneously execute in unison, which is in contrast to traditional, multi-threaded parallel scheduling, where a parallel task may spawn multiple threads, and each thread will be scheduled independently of other threads of the same task. While increasing research efforts on hard real-time (HRT) gang scheduling have recently been seen, the problem of gang scheduling in the context of soft real-time (SRT) systems, where provably bounded deadline tardiness can be tolerated, has hardly been studied yet. In this article, we derive and prove the first tardiness bounds for sporadic gang task systems under preemptive GEDF scheduling. A total utilization bound for SRT-schedulability is required for ensuring such tardiness bounds but it is shown to be tight with respect to the platform capacity and maximum parallelism-induced idleness. Furthermore, we also empirically evaluate the effects of different degrees of task parallelism upon the SRT-schedulability.

中文翻译：

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抢先式全局 EDF 调度下零星团伙任务的迟到界限


随着网络物理系统自主性不断增强的趋势，并行嵌入式架构使设备能够更好地处理此类自主系统所需的大量数据和密集计算。然而，虽然高度并行平台的爆炸式增长使得使用这些平台的应用程序/设备的数量成比例增长，但嵌入式系统社区对如何使用并行平台构建时间可预测、安全关键的系统的理解并没有保持增长。步伐。作为一种动机良好但具有挑战性的并行调度模型，分组调度要求每个并行任务的所有并行线程同时一致执行，这与传统的多线程并行调度相反，在传统的多线程并行调度中，一个并行任务可能会产生多个线程，并且每个线程将独立于同一任务的其他线程进行调度。虽然最近对硬实时（HRT）组调度的研究工作不断增加，但在软实时（SRT）系统背景下的组调度问题却几乎没有被研究过，在软实时（SRT）系统中，可证明有界的最后期限延迟是可以容忍的然而。在本文中，我们推导并证明了抢占式 GEDF 调度下零星组任务系统的第一个延迟界限。为了确保这种延迟界限，需要 SRT 调度性的总利用率界限，但事实证明，它对于平台容量和最大并行性引起的空闲来说是严格的。此外，我们还根据经验评估了不同程度的任务并行性对 SRT 可调度性的影响。