Parallel implementations of three scientific applications using LB_migrate

Abstract

In this paper we focus on the implementation of large scientific applications with LB_Migrate, a dynamic load balancing library. The library employs dynamic loop scheduling techniques to address performance degradation factors due to load imbalance, provides a flexible interface with the native data structure of the application, and performs data migration. The library is reusable and it is not application specific. For initial testing, the library was employed in three applications: the profiling of an automatic quadrature routine, the simulation of a hybrid model for image denoising, and N-body simulations. We discuss the original applications without the library, the changes made to the applications to be able to interface with the library, and we present experimental results. Performance results indicate that the library adds minimal overhead, up to 6%, and it varies from application to application. However the benefits gained from the use of the library are substantial.