As technology advances towards the deep submicron devices, all digital systems are expected to be remarkably vulnerable to single event upset (SEU)-induced transient faults with the continuous shrinking of the feature size and reducing of the threshold voltage. However, for the current rate of transient fault arrival, fault occurrences are expected to remain infrequent in the foreseeable future and fault-free operation will continue to dominate, which necessitates designing hard real-time embedded systems assuming no fault occurrences while maintaining the schedule timeliness when faults occur in burst.;This dissertation explores the joint optimization of fault-tolerance and energy in addition to timeliness for fixed-priority-based hard real-time embedded systems. For uniprocessor systems, two low-cost offline scheduling schemes with varying granularity of dynamic voltage scaling (DVS) policies are designed that enable the dynamic extensions of the offline schedules to adapt to the runtime behavior of fault occurrences. The optimality, complexity, fault-tolerance, and energy consumption of the proposed schemes are investigated and compared with those of the state-of-art optimal schemes. Two dynamic scheduling schemes that re-evaluate DVS policies at runtime to achieve energy savings are also devised.;Energy-efficient task allocation and scheduling schemes with deterministic fault-tolerance capabilities for symmetric multiprocessor or multi-core hard real-time systems aim at achieving optimum energy savings in the absence of faults and meeting application timing requirements in the worst case faults at the cost of energy inefficiency. A novel task allocation scheme with proven optimal load-balancing property is designed for optimum energy savings, and an optimistic fault-tolerance task allocation and scheduling scheme is proposed to achieve optimum energy savings in reliable hard real-time multiprocessor systems.;Finally, a real-life test bed comprising Intel Core Duo T2500 processor with DVS capability and running Linux Fedora 8-based hard real-time scheduling has been developed, and the proposed energy-efficient fault-tolerance task allocation and scheduling schemes are implemented and validated on the test bed. The experimental results on the test bed are reported and the discrepancies between the experimental results and simulation results are investigated.;As a whole, this dissertation investigates and justifies the designing of energy-efficient fault-tolerance hard real-time systems for the best case of fault occurrences without compromising the schedule timeliness. The research results show that this design strategy is particularly promising for emerging applications where timeliness, fault-tolerance, and energy dimensions need to be simultaneously addressed.
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机译：随着技术向深亚微米器件发展，随着特征尺寸的不断缩小和阈值电压的降低，所有数字系统都将极易遭受单事件翻转（SEU）引起的瞬态故障。但是，对于当前的瞬时故障到达率，在可预见的将来，故障的发生率预计将保持很少，并且无故障操作将继续占主导地位，这需要设计硬实时嵌入式系统，假设没有故障发生，同时保持计划的及时性。当突发事件中发生故障时，本文研究了基于固定优先级的硬实时嵌入式系统的实时性和容错性与能量的联合优化。对于单处理器系统，设计了两种具有不同动态电压缩放（DVS）策略粒度的低成本脱机调度方案，这些方案使脱机调度的动态扩展能够适应故障事件的运行时行为。研究了所提方案的最优性，复杂性，容错性和能耗，并将其与最新的最优方案进行了比较。还设计了两种可在运行时重新评估DVS策略以实现节能的动态调度方案;具有对称性多处理器或多核硬实时系统的具有确定性容错能力的节能任务分配和调度方案旨在实现在没有故障的情况下实现最佳节能，并在最坏情况下满足应用时序要求，但以能源效率低下为代价。设计了一种经过验证的最佳负载均衡特性的新型任务分配方案，以实现最佳的节能效果，并提出了一种乐观的容错任务分配和调度方案，以在可靠的硬实时多处理器系统中实现最佳的节能效果。开发了包含具有DVS功能的Intel Core Duo T2500处理器并运行基于Linux Fedora 8的硬实时调度的实际测试台，并在此平台上实施并验证了所提出的高效节能容错任务分配和调度方案。测试床。报告了在试验台上的实验结果，并研究了实验结果与模拟结果之间的差异。总体而言，本文研究并证明了在最佳情况下高效节能的容错硬实时系统的设计在不影响计划及时性的前提下对故障进行分析。研究结果表明，对于需要同时解决及时性，容错性和能量尺寸的新兴应用，这种设计策略特别有希望。
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