Task tree scheduling onto linear arrays using tabu search

Tabu search is a promising optimisation heuristic that has been successfully applied to the solution of many combinatorial optimisation problems, yielding optimal or near optimal results. An efficient algorithm based on tabu search is presented, designated as TASS, for the problem of scheduling a tree-like task graph (task tree) onto linear arrays of processors, with the aim of minimising the system response time. The linear processor arrays implemented in VLSI/ULSI technology provide an affordable and cost-effective solution for special applications that can be represented by task trees. The performance of the proposed tabu search-based algorithm is evaluated for a set of test problems selected from the literature. Comparison of results obtained by the proposed algorithm with results reported by previous techniques, shows a considerable improvement in the system response time