Abstract: Loop is one of the most important structures that can be parallelized effectively with OpenMP. However, the performance outcome will depends on the threads number, size of loop body and scheduling scheme. In order to get better performance and reach a better trade-off between scheduling overhead and load balance, this paper implemented the trapezoid scheduling scheme using OMPi, a open-source compiler that supports OpenMP API. The evaluation results show that; with normal threads number, the trapezoid self-scheduling will yield better performance than guided self-scheduling in case of the decreasing- and irregular-loop structure.

Key words: OpenMP, Load balance, Scheduling scheme, Trapezoid self-scheduling, OMPi