CSR--EHS--Reconciling Operating System and Hardware Thermal Control

该项目开发了具有动态热管理（DTM-也称为热节流）的系统的实时控制。DTM允许冷却解决方案的设计低于最坏的情况，这种方法随着功率密度的指数级增长和外形尺寸的缩小而变得必要。在运行时，如果散热超过冷却解决方案的能力持续一段时间，芯片温度接近危险水平，DTM将处理器置于某种形式的低功耗模式，使温度回落到安全水平。问题是，当前系统中的DTM通常在热应力即将来临时由硬件自主地接合，而没有任何警告。这与实时调度不兼容。 为了协调运行时热管理与实时控制，新的调度算法和必要的软件和硬件支持正在开发中的这项研究。这包括快速估计工作负载的未来热负载，估计DTM的可能性和调度影响，以及允许操作系统选择最方便的时间来使用DTM的新方法。所提出的技术进行评估的真实的测试平台与现实的工作负载。

This project develops real-time control of systems with dynamic thermal management (DTM-also called thermal throttling). DTM allows the cooling solution to be designed for less than the worst case, an approach that is becoming necessary with exponentially increasing power densities and shrinking form factors. At runtime, if heat dissipation exceeds the cooling solution's capacity for a sustained period of time and on-chip temperatures approach dangerous levels, DTM places the processor in some form of low-power mode that allows temperatures to fall back to a safe level. The problem is that DTM in current systems is typically engaged autonomously by the hardware when thermal stress is imminent, without any warning. This is incompatible with real-time scheduling. To reconcile runtime thermal management with real-time control, new scheduling algorithms and requisite software and hardware support are being developed in this research. This includes fast estimation of a workload's future thermal load, estimation of the likelihood and scheduling impact of DTM, and new methods that allow the operating system to choose the most convenient time to engage DTM. The proposed techniques are evaluated on a real testbed with realistic workloads.