CNS Core: Small: Rethinking Runtime Power Management for Mobile System-on-a-Chip

运行时电源管理（PM）关注的是在系统仍在为用户服务时，将计算机系统的空闲组件置于节电模式。电源管理对移动系统的电池寿命和热管理越来越重要，移动系统的计算核心是片上系统（SoC），通常集成了数十个和数百个组件和数十亿个晶体管。现有系统响应运行时PM的设备驱动程序。设备驱动程序是一种软件程序，它控制连接到计算机上的特定类型的硬件设备。这种PM方法不仅在广泛使用的移动系统中导致未优化的，或者经常完全没有运行时PM，而且由于使用高性能的中央处理单元（CPU）而导致高开销。这个项目的目标是通过完全重新思考移动soc的运行时PM来减轻运行时PM的设备驱动程序和CPU。首先，它将研究一种新的架构，其中单个操作系统实体在不涉及其设备驱动程序的情况下判断SoC组件是否空闲。其次，该项目将为操作系统提供支持，这样运行时PM逻辑就可以完全在现代移动系统中可用的超低功耗计算核心上实现。该项目将使用基于Android/ linux的测试平台和基于现场可编程门阵列（FPGA）的SoC原型硬件对其技术创新进行原型设计和评估。该项目将利用与行业领导者的合作，确保及时将技术转移到工业中，并对移动系统及其soc的商业开发产生广泛影响。该项目将为教学移动和嵌入式系统提供新的模块，并为高中生和少数民族学生提供一个平台。由于移动系统正在向服务不足的人群提供获取信息技术的途径，并被用于专业用途，因此通过提高电池寿命和可用性，该项目将在全球范围内产生积极的社会经济影响。研究成果将在学术会议和期刊上发表。由此产生的硬件设计、软件和数据将是开源的，并且可以从http://download.recg.org访问存储库免费获得。该存储库将在项目完成后至少维护五年。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Runtime power management (PM) is concerned with putting idle components of a computer system into power-saving modes while the system is still serving its user. Power management is increasingly important to the battery lifetime and thermal management of mobile systems whose computational heart, a system-on-a-chip (SoC), often integrates tens and hundreds of components and billions of transistors. Existing systems reply on device drivers for runtime PM. A device driver is a software program that controls a particular type of hardware device attached to a computer. This approach to PM not only leads to unoptimized, or often complete absence of runtime PM in widely used mobile systems, but also incurs high overhead by engaging the high-power central processing unit (CPU). The goal of this project is to relieve device drivers and the CPU of runtime PM by completely rethinking runtime PM of mobile SoCs. First, it will investigate a novel architecture in which a single operating system entity reasons whether a SoC component is idle without involving its device driver. Second, the project will contribute to operating system support such that the runtime PM logic can be entirely realized on an ultra-low-power computing core available in modern mobile systems. The project will prototype and evaluate its technical innovations with Android/Linux-based testbeds and Field-Programmable Gate Array (FPGA)-based SoC prototyping hardware.The project will leverage collaborations with industry leaders to ensure a timely transfer of technologies into industry and a broad impact on the commercial development of mobile systems and their SoCs. The project will provide new modules for teaching mobile and embedded systems and a platform to engage high-school and minority students. As mobile systems are providing access to information technologies to underserved populations and being adopted for professional uses, by improving their battery lifetime and therefore usability, the project will have a positive socio-economic impact globally. Research results will be published in academic conferences and journals. Resulting hardware design, software, and data will be made open-source and freely available at a repository accessible from http://download.recg.org. This repository will be maintained at least five years after the project is completed.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.