Feedback Techniques for Integrating Power Management and Quality of Service in Servers

点击翻译按钮获取中文摘要

Increased awareness of power concerns and recent approaches to improveenergy efficiency and heat dissipation in computer systems have notimmediately translated into rich, adaptable, power-aware applications.This lack of effectiveness is particularly evident in power-awarereal-time computing, where efforts to bridge the gap between hardwareand software have generally been limited to developing new schedulersthat operate by modulating a relatively high-level hardware controlsuch as voltage scaling and frequency scaling. The problem with thisapproach is that the hardware controls operate at too gross a level tobe effective in dynamic, poorly-modeled application scenarios.This project develops a feedback-based, control-theoretic approach tooptimize and balance, at runtime, power consumption and real-timeperformance. This approach not only integrates hardware-levelpower-management techniques with real-time and quality-of-service(QoS) constraints, but also integrates a range of hardwarepower-management techniques at different granularities into a unifiedframework that allows better task-level control of power management.This enables finer control of power/performance tradeoffs by theoperating system, and permits applications to dynamically adjust thesystem's and chip's power-saving configuration on a per-task basis tomeet specific performance requirements while reducing powerconsumption. With the new functionality provided by this project, aricher class of power-aware applications can be developed to providevaluable user experiences in next-generation, real-time environments.The project specifically focuses the requirements of web serverfarms where energy and cooling costs are substantial and where the webservices provide differentiated levels of QoS, thus motivating apower-aware framework that balances performance, QoS requirements, andenergy costs.