Exploring NoC Virtualization Alternatives in CMPs

Chip Multiprocessor systems (CMPs) contain more and more cores in every new generation. However, applications for these systems do not scale at the same pace. Thus, in order to obtain a good utilization several applications will need to coexist in the system and in those cases virtualization of the CMP system will become mandatory. In this paper we analyze two virtualization strategies at NoC-level aiming to isolate the traffic generated by each application to reduce or even eliminate interferences among messages belonging to different applications. The first model handles most interferences among messages with a virtual-channels (VCs) implementation minimizing both execution time and network latency. However, using VCs results in area and power overhead due to the cost of control and buffer implementation. In contrast, the second model is based on the resource partitioning which results in a space partitioning of the CMP chip in several regions. The paper shows a comparison of both models and identifies their main advantages and disadvantages.