Exploiting OpenMP Malleability with Free Agent Threads and DLB

Joel Criado, Víctor López, Joan Vinyals-Ylla-Catala, Guillem Ramirez-Miranda, Xavier Teruel, Marta Garcia-Gasulla

Abstract: This paper presents the evolution of the free agent threads for OpenMP to the new role-shifting threads model and their integration with the Dynamic Load Balance (DLB) library. We demonstrate how DLB efficiently manages the malleability exposed by the role-shifting threads to address load imbalance issues. We use two real-world scientific applications, one of them with a coupling case, to illustrate the potential of this approach. In addition, we also demonstrate that the new implementation is more usable than the former one, letting the runtime system automatically make decisions that were to be made by the programmer previously. All software is released open source.