Implementation and analysis of hotspot mitigation in mesh NoCs by cost-effective deflection routing technique

Network-on-Chip (NoC) serves as an efficient communication framework among the components of Chip MultiProcessors (CMPs). With increasing number of computation intensive applications communication between cores also increases, which creates high congestion resulting in network performance degradation. Handling congestion is a key network management issue in NoC. Hotspots are non-uniform traffic formation near cores where some cores need to handle a relatively higher traffic compared to others. Prolonged presence of these hotspots increases the communication latency of packets flowing through them. This work proposes a novel approach to identify destination hotspots and upon identification, packets are de-routed away from these hotspot cores using a cost-effective deflection routing technique. Experimental results show that in highly congested networks, our approach detects destination hotspots with great accuracy. De-routing of packets away from hotspots help them achieve congestion relief thereby decreasing the average latency of packets flowing in the network.