Recently, high performance packet I/O frameworks continue to flourish for their ability to process packets from high-speed links. To achieve high throughput and low latency, high performance packet I/O frameworks usually employ busy polling. As busy polling will burn all CPU cycles even if there's no packet to process, these frameworks are quite power inefficient. However, exploiting power management techniques such as DVFS and LPI in the frameworks is challenging, because neither the OS nor the frameworks can provide information (e.g., actual CPU utilization, available idle period, or the target frequency) required by these techniques. In this article, we establish a model that can formulate the packet processing flow of high performance packet I/O to help and address the above challenges. From the model, we can deduce the information needed for power management techniques, and gain the insights to balance the power and latency. After suggesting to use pause instruction to reduce CPU power within short idle period, we propose two approaches to conduct power conservation for high performance packet I/O: one with the aid of traffic information and the other without. Experiments with Intel DPDK show that both approaches can achieve significant power reduction with little latency increase.

中文翻译：

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迈向节能的高性能数据包 I/O

最近，高性能数据包 I/O 框架因其处理来自高速链路的数据包的能力而继续蓬勃发展。为了实现高吞吐量和低延迟，高性能数据包 I/O 框架通常采用忙轮询。由于即使没有要处理的数据包，忙轮询也会消耗所有 CPU 周期，因此这些框架非常低效。然而，在框架中利用 DVFS 和 LPI 等电源管理技术具有挑战性，因为操作系统和框架都无法提供这些技术所需的信息（例如，实际 CPU 利用率、可用空闲时间或目标频率）。在本文中，我们建立了一个模型，可以制定高性能数据包 I/O 的数据包处理流程，以帮助和解决上述挑战。从模型来看，我们可以推断出电源管理技术所需的信息，并获得平衡电源和延迟的见解。在建议使用暂停指令在较短的空闲时间内降低 CPU 功率后，我们提出了两种对高性能数据包 I/O 进行节能的方法：一种借助流量信息，另一种不借助。英特尔 DPDK 的实验表明，这两种方法都可以显着降低功耗，而延迟几乎没有增加。