EAGER: HAWKEYE: A Cross-Layer Resilient Architecture to Tradeoff Program Accuracy and Resilience Overheads

随着半导体技术扩展到亚纳米尺度，光刻模式和制造过程中的微小扰动使计算硬件容易受到不可预测的功能偏差的影响。此外，随着越来越严格的功率限制，硬件设计现在依赖于标称和近阈值区域之间的动态电压缩放，这加剧了可靠性问题。这些趋势在不增加功耗的情况下激发了对系统弹性的需求。本项目提出了一种实现高效弹性的新方法，其中硬件的覆盖范围有一定的保证，而计算效率是以影响程序准确性为代价的。该策略侧重于数据分析应用程序，因为它们自然地提供了由于输入的非结构化性质而导致的程序准确性的权衡，以及用于解决这些棘手问题的近似算法。在软件层面，项目正在开发方法来对程序中的关键代码区域和非关键代码区域进行分类：关键代码影响程序的正确性和结果，其功能不能以任何方式改变；非关键代码会影响程序的准确性，因此它可以容忍错误。随后，硬件仅对关键代码实现更强的弹性方法（例如，冗余执行）。对于非关键代码，轻量级弹性方案可确保程序的正确性。如果成功，该项目将朝着一个新的严格框架迈出重要的一步，该框架可以推理并保证系统的弹性，以及程序的性能、功率和计算的准确性。拟议的研究通过整合现有计算机体系结构和系统设计课程的模块，并通过建立REU站点和丰富计划进行推广，为课程开发和学生培训提供了重要的更广泛的影响。该项目承诺透明的弹性保证，这将产生重大的社会影响：企业和任务机构将能够以可量化的方式推理其软件和硬件基础设施的弹性与效率权衡。鉴于许多应用领域（如医疗保健、国防、金融、运输和汽车）对系统可靠性的认识不断提高，这是向前迈出的关键一步。

With semiconductor technology scaling to sub-nanometer scales, minute perturbations in lithography patterns and manufacturing processes make the computing hardware vulnerable to unpredictable deviations in functionality. Further, with increasingly strict power constraints, hardware designs are now reliant on dynamic voltage scaling between nominal and near-threshold regions, which exacerbates the reliability problem. These trends motivate the need for system resiliency without increasing power consumption. This project proposes a new method to achieve efficient resiliency, where hardware's coverage is bounded with certain guarantees, while computational efficiency is traded off at the cost of affecting program accuracy. The strategy focuses on data analytic applications since they naturally offer tradeoffs in program accuracy due to the unstructured nature of inputs, and the approximate algorithms used to solve these otherwise intractable problems. At the software level, the project is developing methods to classify crucial versus non-crucial code regions in a program: the crucial code affects program correctness and outcome, its functionality cannot be altered in any way; non-crucial code affects program accuracy, therefore it could tolerate errors. The hardware subsequently implements stronger resiliency methods (e.g., redundant execution) only for crucial code. For the non-crucial code, lightweight resiliency schemes ensure program correctness. If successful, this project will be a major step towards a new rigorous framework to reason and guarantee system resiliency alongside a program's performance, power, and accuracy of computation. The proposed research provides for significant broader impacts related to curriculum development and student training through integration of modules in existing computer architecture and system design courses, and outreach through established REU sites and enrichment programs. The project promises transparent resiliency guarantees and this will have a major societal impact: enterprises and mission agencies will be able to reason in a quantifiable way about the resiliency versus efficiency tradeoffs in their software and hardware infrastructure. This is a crucial step forward given the increased awareness of system reliability in many application domains, such as healthcare, defense, finance, transportation, and automotive.