Spatial Distributions versus Multicast Distributions: Traffic Modeling of Chip Multiprocessor Networks
Dietmar Tutsch and Daniel Lüdtke
International Symposium on Performance Evaluation of Computer and Telecommunication Systems (SPECTS 2007)
San Diego, California (USA), July 16-18, 2007
SPECTS_Summary
Chip multiprocessors (CMPs) came to the center of interest in recent years. They consist of multiple processor cores on a single chip. These cores are connected on-chip by an appropriate network. To investigate how a multicore processor behaves dependent on the chosen network-on-chip topology, a corresponding model must be established for performance evaluation. Modeling the entire system would lead to high model complexity. Thus, it is more reasonable to exclude the cores and to simply model stochastically the detached network. The cores are replaced by traffic generators which must provide reasonable CMP traffic. It usually consists of multicasts and a particular spatial distribution. Because the traffic is not exactly known, both, multicasts and spatial traffic, are described as stochastic distributions for model input. But not all multicast distributions can be achieved with a particular desired spatial distribution and vice versa. Thus, it is important to check for the compatibility of the spatial distribution and the multicasts that the modeler is willing to investigate. Such a compatibility check is provided by the algorithm presented in this paper. It prevents from inconsistent traffic parameters while modeling.