Evaluating Livelock Control Mechanisms in a Gigabit Network

Networked systems are susceptible to transient overload, which can lead to system crash due to resource exhaustion. In the absence of appropriate mechanisms, a system can enter and persist in a state of livelock during the overload period. This paper presents an evaluation of two mechanisms for livelock control experienced in computers of different capacities in a gigabit network. The first mechanism is called interrupt moderation and is implemented in most of today´s high-performance network interfaces. The second mechanism, called NAPI, is a new API for Linux network drivers, which implements a set of strategies to handle packet overload and avoid its consequences. We show that NAPI is more efficient than interrupt moderation in many aspects, including system stability in the case of huge traffic and high CPU usage.