The effectiveness of affinity-based scheduling in multiprocessor network protocol processing (extended version)

Techtdques for avoiding the high memory overheads found on many modern shared-memory mtdtiprocessors are of increasing importance in the development of high-performance mtdtiprocessor protocol implementations. One such technique is processor-cache aflirdty schedtding, which can significantly lower packet latency and substantially increase protocol processing throughput (30). In tlds paper, we evaluate severtd aspects of the effectiveness of affinity-based scheduling in mtdtiproeessor network protocol processing, under packet-level and connection- level parallelization approaches Speeifieally, we evaluate the performance of the scheduling technique 1) when a large number of streams are concurrently supported, 2) when processing in- cludes copying of uncached packet data, 3) as applied to send-side protocol processing, and 4) in the presence of stream burstiness and source locality, two well-known properties of network t-c. We find that ~ty-based schedtding performs well under these conditions, emphasizing its rubustneatsand general effectiveness in multiprocessor network processing. In addition, we explore a technique which improves the cachhsg behavior and available packet-level concurrency under connection-level parallelism, and find performance improves dramatically.