Back Suction: Service Guarantees for Latency-Sensitive On-chip Networks

Networks-on-chip for future many-core processor platforms face an increasing diversity of traffic requirements, ranging from streaming traffic with real-time requirements to bursty latency-sensitive best-effort traffic from general-purpose processors with caches. In this paper, we propose Back Suction, a novel flow-control scheme to implement quality-of-service. Traffic with service guarantees is selectively prioritized upon low buffer occupancy of downstream routers. As a result, best-effort traffic is preferred for an improved latency as long as guaranteed service traffic makes sufficient progress. We present a formal analysis and an experimental evaluation of the Back Suction scheme showing improved latency of best effort traffic when compared to current approaches even under formal service guarantees for streaming traffic.