An improved simulated annealing heuristic for static partitioning of task graphs onto heterogeneous architectures

We present a simulated annealing based partitioning technique for mapping task graphs, onto heterogeneous processing architectures. Task partitioning onto homogeneous architectures to minimize the makespan of a task graph, is a known NP-hard problem. Heterogeneity greatly complicates the aforementioned partitioning problem, thus making heuristic solutions essential. A number of heuristic approaches have been proposed, some using simulated annealing. We propose a simulated annealing method with a novel NEXT STATE function to enable exploration of different regions of the global search space when the annealing temperature is high and making the search more local as the temperature drops. The novelty of our approach is two fold: (1) we go a step further than the existing scientific literature, considering heterogeneity at levels of task parallelism, data parallelism and communication. (2) We present a novel algorithm that uses simulated annealing to find better partitions in the presence of heterogeneous architectures, data parallel execution units, and significant data communication costs. We conduct a statistical analysis of the performance of the proposed method, which shows that our approach clearly outperforms the existing simulated annealing method.