ETA: experience with an Intel® Xeon™ processor as a packet processing engine

The ETA (embedded transport acceleration) project at Intel Research and Development has developed a software prototype that uses one of the Intel® Xeon™ processors in a multi-processor server as a packet processing engine. The prototype is used as a vehicle for empirical measurement and analysis of a highly programmable packet processing engine that is closely tied to the server's core CPU and memory complex. The usage model for the prototype is the acceleration of server TCP/IP networking. The ETA prototype runs in an asymmetric multiprocessing mode, in that the packet processing engine does not run as a general computing resource for the host operating system. We show an effective method of interfacing the packet processing engine to the host processors using efficient asynchronous queuing mechanisms. This paper describes the ETA software architecture, the ETA prototype, and details the measurement and analysis that has been performed to date. Test results include running the packet processing engine in single-threaded mode, as well as in multi-threaded mode using Intel's hyper-threading technology (HT). Performance data gathered for network throughput and host CPU utilization show a significant improvement when compared to the standard TCP/IP networking stack.