Gem5Tune: A Parameter Auto-Tuning Framework for Gem5 Simulator to Reduce Errors

Computer architecture simulators are widely used to explore new architectures, e.g., the gem5 simulator. However, gem5 has significant performance errors that may lead to misleading research results. Researchers typically reduce errors with the target machine by manual calibration methods, which are time-consuming and require significant expertise. This paper presents gem5Tune, a parameter auto-tuning framework for the gem5 simulator to reduce errors. Applying black-box optimization (BBO) methods, recommended for TPE-based Bayesian optimization, gem5Tune minimizes the error between gem5 and the target machine within a limited number of iterations. Three optimization methods, instruction calibration, sensitivity analysis, and dynamic pruning, are proposed to accelerate the error convergence. Experimental results show that compared to the manual calibration method, gem5Tune significantly reduces performance errors between gem5 and three modern ARM servers by more than 10% (13.83%, 10.86%, and 25.22%, respectively) for SPEC CPU benchmarks. It also scales effectively to PARSEC and SPLASH-2x benchmarks and reduces the errors of architectural events.