Accelerated Computing research group
Bayesian Optimization for auto-tuning GPU kernels

Supercomputing 2021 — I traveled to St. Louis to present my paper on the use of Bayesian Optimization for auto-tuning GPU kernels. This paper was accepted in the 12th IEEE International Workshop on Performance Modeling, Benchmarking and Simulation of High Performance Computer Systems (PMBS) held in conjunction with SC21: The International Conference for High Performance Computing, Networking, Storage and Analysis.

Abstract

Finding optimal parameter configurations for tunable GPU kernels is a non-trivial exercise for large search spaces, even when automated. This poses an optimization task on a non-convex search space, using an expensive to evaluate function with unknown derivative. These characteristics make a good candidate for Bayesian Optimization, which has not been applied to this problem before. However, the application of Bayesian Optimization to this problem is challenging. We demonstrate how to deal with the rough, discrete, constrained search spaces, containing invalid configurations. We introduce a novel contextual variance exploration factor, as well as new acquisition functions with improved scalability, combined with an informed acquisition function selection mechanism. By comparing the performance of our Bayesian Optimization implementation on various test cases to the existing search strategies in Kernel Tuner, as well as other Bayesian Optimization implementations, we demonstrate that our search strategies generalize well and consistently outperform other search strategies by a wide margin.

Citation

Bayesian Optimization for auto-tuning GPU kernels
F.J. Willemsen, R.V. van Nieuwpoort, B. van Werkhoven
International Workshop on Performance Modeling, Benchmarking and Simulation of High Performance Computer Systems (PMBS) at Supercomputing (SC21) 2021
https://doi.org/10.1109/PMBS54543.2021.00017

Written by

Floris-Jan Willemsen

Floris-Jan is a PhD Candidate at Leiden University and the Netherlands eScience Center. His research focusses on intelligent, automated optimization of GPU software.