EHS: Energy-Aware CPU and I/O Scheduling for Embedded, Real-Time Systems

CNS 0409382史蒂芬·M·戈达德大学林肯分校标题：用于嵌入式实时系统的节能中央处理器和I/O调度嵌入式实时系统通常具有严格的功率限制，需要在处理器和输入/输出(I/O)设备中采用积极的节能技术。该项目正在研究具有灵活任务模型的嵌入式、硬实时系统的节能处理器和I/O调度。这一结果将为在不可预测的环境中执行的反应式嵌入式实时系统(如移动机器人)提供增加节能的机会。该项目关注两个核心问题：零星任务的处理器节能和周期任务I/O设备的节能。处理器节能：在嵌入式实时系统动态功耗的背景下，周期任务模型的处理器节能已被广泛研究。然而，节能与更灵活的实时任务模型，如零星任务模型，仍然是一个悬而未决的问题。该项目正在研究截止日期不等于各自周期的零星任务的处理器能量守恒、非抢占式最早截止日期优先(EDF)调度、EDF调度下的共享资源以及零星任务模型的广义版本。具有周期性任务的I/O设备中的节能：本研究正在研究在周期性任务模型下动态重新排序作业执行以在I/O设备中节能的方法。虽然该项目的这一方面的重点是I/O设备中的节能，但当仅支持频率调节(而不支持电压调节)时，该方法将处理器的动态功耗降至最低。它还通过将较短的空闲周期分组为较长的时间间隔来降低泄漏功耗，在较长的时间间隔内可以使处理器处于空闲状态，而不会危及时间正确性。

CNS 0409382 Stephen M. Goddard University of Nebraska-LincolnTitle: Energy-Aware CPU and I/O Scheduling for Embedded, Real-Time SystemsEmbedded real-time systems often have severe power constraints that require aggressive energy conservation techniques in both the processor and the Input/Output (I/O) devices. This project is investigating energy-aware processor and I/O scheduling for embedded, hard real-time systems with flexible task models. The results will provide the opportunity for increased energy savings in reactive, embedded, real-time systems that execute in unpredictable environments, such as mobile robots. The project focuses on two central problems: processor energy conservation for sporadic tasks, and energy conservation for I/O devices with periodic tasks.Processor Energy Conservation: Processor energy conservation for the periodic task model has been extensively researched in the context of dynamic power consumption for embedded, real-time systems. However, energy conservation with more flexible real-time task models, such as the sporadic task model, remains an open problem. The project is investigating processor energy conservation for sporadic tasks that have deadlines not equal to their respective periods, non-preemptive earliest-deadline-first (EDF) scheduling, shared resources under EDF scheduling, and generalized versions of the sporadic task model. Energy Conservation in I/O Devices with Periodic Tasks: This research is investigating methods that dynamically re-order job executions to conserve energy in I/O devices under the periodic task model. Though the focus of this aspect of the project is energy conservation in I/O devices, the method minimizes processor dynamic power dissipation when only frequency scaling is supported (and not voltage scaling). It also reduces leakage power consumption by grouping short idle periods into longer intervals of time in which the processor can be made idle without jeopardizing temporal correctness.