| Abstract: | The paper presents analytical and simulation models to study the impact of interrupt overhead on operating system throughput of network elements such as PC‐based routers, servers, and hosts when subjected to high‐speed network traffic. Under such high network traffic, the system throughput will be negatively affected due to interrupt overhead caused by the incoming traffic. We first present an analytical model for the ideal system when interrupt overhead is ignored. We then present two models which describe the impact of high interrupt rate on system throughput. One model is for employing PIO in which network adapters are not equipped with DMA engines, and the other model is for employing DMA in which network adapters are equipped with DMA engines. The paper also describes detailed discrete‐event simulation models for the ideal system and for systems with DMA and PIO. Simulations results as well as reported experimental measurements show that our analytical models are valid and give a good approximation. Our analysis and simulation work can be valuable in providing insight to understand and predict system behaviour, as well as improving and maintaining good host performance. The paper identifies analytically critical design operation points such as that of overload condition. The paper also proposes solutions and recommendations for improving performance. Copyright © 2005 John Wiley & Sons, Ltd. |
