A Case Study Using Automatic Performance Tuning for Large-Scale Scientific Programs

Active Harmony is an automated runtime performance tuning system. In this paper we describe several case studies of using Active Harmony to improve the performance for scientific libraries and applications. We improved the tuning mechanism so it can work iteratively with benchmarking runs. By tuning the computation and data distribution, Active Harmony helps applications that utilize the PETSc library to achieve better load balance and to reduce the execution time up to 18%. For the climate simulation application POP using 480 processors, the tuning results show that by changing the block size and parameter values, the execution time is reduced up to 16.7%. Active Harmony is able to improve GS2, a plasma physics code, up to a factor of 5.1 times faster. The experiment results show that the Active Harmony system is a feasible and useful tool to automated performance tuning for scientific libraries and applications