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

CNS 0409382 Stephen M.戈达德内布拉斯加大学林肯分校题目：嵌入式实时系统的节能CPU和I/O调度嵌入式实时系统通常有严格的功耗限制，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。本项目研究具有灵活任务模型的嵌入式硬实时系统的能量感知处理器和I/O调度。研究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（如移动的机器人）提供更多的节能机会。该项目集中在两个中心问题：处理器的零星任务的节能，和节能的I/O设备周期tasks.Processor节能：处理器节能的周期性任务模型已被广泛研究的背景下，嵌入式，实时系统的动态功耗。然而，节能与更灵活的实时任务模型，如零星的任务模型，仍然是一个悬而未决的问题。该项目正在研究处理器节能的零星任务，有期限不等于他们各自的时期，非抢占式最早期限优先（EDF）调度，共享资源下EDF调度，和广义版本的零星任务模型。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节省I/O设备中的能量的方法。虽然该项目这方面的重点是I/O设备的节能，但当仅支持频率缩放（而不支持电压缩放）时，该方法可最大限度地降低处理器动态功耗。它还通过将短空闲周期分组为较长的时间间隔来减少泄漏功耗，在较长的时间间隔中，处理器可以处于空闲状态，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.