Mario Nemirovsky

A Massively Multithreaded Packet Processor

Publisher Summary This chapter presents Porthos, a new packet processor designed for stateful applications. The design of Porthos is derived from fundamental observations about stateful networking applications: a significant number of off-chip accesses with little locality need to be supported for each packet. To efficiently implement the requisite large number of parallel packets, Porthos implements a massively multithreaded processor with a strong bias toward efficiency over single-threaded performance. Besides providing a massive multithreading packet processor, another key innovation in Porthos is the implementation of a loosely coupled processor/memory architecture. This allows the performance to be optimized by software and provides topological flexibility and a uniform software model. Furthermore, the use of flow gating allows efficient memory synchronization with minimal software porting issues.