Lutmap: A Dynamic Heuristic Application Mapping Algorithm Based On Lookup Tables

In this paper, we propose and investigate a dynamic heuristic mapping algorithm with lookup table optimizations. Distributed and parallel computing are trends due to the performance requirement of modern applications. Application mapping in a multiprocessor system is therefore critical due to the dynamic and unpredictable nature of the applications. We analyse the communication delay among different tasks in an application. A fundamental algorithm is analysed to optimize the average delay of the mapping region. We discuss and evaluate the effectiveness of the algorithm in terms of average intra-application latency. Results from synthetic applications revealed that average latencies from the mapping regions of the fundamental algorithm have reduced up to 23% compared with the incremental mapping. By noticing the time overhead of the algorithm due to extra number of search spaces, we introduce a mechanism with lookup tables to speed up the process of searching optimized mapping regions. The lookup table is examined with both size and construction time. Experiments shown that the lookup table is small enough to fit into the cache, and the table can be constructed in milliseconds in most practical cases. The results from real applications show that the average execution time of applications of the proposed algorithm has reduced by 15.2% compared with the first fit algorithm.