Design considerations for network processor operating systems

Network processors (NPs) promise a flexible, programmable packet processing infrastructure for network systems. To make full use of the capabilities of network processors, it is imperative to provide the ability to dynamically adapt to changing traffic patterns and to provide run-time support in the form of a network processor operating system. The differences to existing operating systems and the main challenges lie in the multiprocessor nature of NPs, their on-chip resources constraints, and the real-time processing requirements. In this paper, we explore the key design tradeoffs that need to be considered when designing a network processor operating system. In particular, we explore the performance impact of (1) application analysis for partitioning, (2) network traffic characterization, (3) workload mapping, and (4) run-time adaptation. We present and discuss qualitative and quantitative results in the context of a particular application analysis and mapping framework, but the observations and conclusions are generally applicable to any run-time environment for network processors.