This work introduces a model-based framework that reveals the idle opportunity of modern servers running latency-critical applications. Specifically, three queuing models, M/M/1, cxM/M/1, and M/M/c, are used to estimate the theoretical idle time distribution at the CPU core and system (package) level. A comparison of the actual idleness of a real server and that from the theoretical models reveals significant missed opportunities to enter deep idle states. This inefficiency is attributed to the idle-governor inaccuracy and the high latency to transition to/from legacy deep-idle states. The proposed methodology offers the means for an early-stage design exploration and insights into idle time behavior and opportunities for varying server system configurations and load.

翻译：本研究提出一种基于模型的框架，用于揭示运行延迟敏感型应用的现代服务器存在的闲置机遇。具体而言，采用M/M/1、cxM/M/1和M/M/c三种排队模型来估算CPU核心及系统（封装）层面的理论闲置时间分布。通过对比实际服务器与理论模型的闲置状态，发现系统存在大量未能进入深度休眠状态的错失机会。这种低效现象可归因于空闲调控器的不准确性以及传统深度休眠状态转换的高延迟特性。所提出的方法论为早期设计探索提供了工具，能够深入理解不同服务器系统配置与负载条件下的闲置时间行为特征及其优化潜力。