The 23rd International European Conference on Parallel and Distributed Computing, Europar 2017, will take place in Santiago de Compostela, the capital of Galicia, Spain, and endpoint of the Way of Saint-James, from August 28 to September 1st. It is organized by the ETSE of the Universidade de Santiago de Compostela in collaboration with the Centro de Investigación en Tecnoloxías da Información (CiTIUS).
Mont-Blanc partners University of Cantabria and Barcelona Supercomputing Center will present their paper:
To distribute or not to distribute: the question of load balancing for performance or energy
Abstract: Heterogeneous systems are nowadays a common choice in the path to Exascale. Through the use of accelerators they offer outstanding energy eciency. The programming of these devices employs the host-device model, which is suboptimal as CPU remains idle during kernel executions, but still consumes energy. Making the CPU contribute computing effort might improve the performance and energy consumption of the system. This paper analyses the advantages of this approach and sets the limits of when its beneficial. The claims are supported by a set of models that determine how to share a single data-parallel task between the CPU and the accelerator for optimum performance, energy consumption or eciency. Interestingly, the models show that optimising performance does not always mean optimum energy or efficiency as well.
The paper experimentally validates the models, which represent an invaluable tool for programmers when faced with the dilemma of whether to distribute their workload in these systems.