Advance Virtual Channel Reservation

Abstract

We present a smart communication service called Advance Virtual Channel Reservation (AVCR) to provide a highway to target packets, which can greatly reduce their contention delay in NoC. AVCR takes advantage of the fact that we can know or predict the destination of some packets ahead of their arrival at the network interface (NI). Exploiting the time interval before a packet is ready, AVCR establishes an end-to-end highway from the source NI to the destination NI. This highway is built up by reserving the virtual channel (VC) resources ahead of the target packet transmission and offering priority service to flits in the reserved VC in the wormhole router, which can avoid the target packets’ VC allocation and switch arbitration delay. Additionally, optimization schemes are proposed to increase resources utilization and system performance. We evaluate AVCR with GEM5 full-system simulations by using 24 benchmarks in PARSEC and OMP2012. Compared to the state-of-art mechanisms and the priority-based mechanism, experimental results show that our mechanism can significantly reduce the target packets’ transfer latency and thus effectively decrease the average region-of-interest (ROI) time by 18.1 percent (maximally by 29.4 percent) across all benchmarks.