Toward a general framework for jointly processor-workload empirical modeling

The complexity of state-of-the-art processor architectures and their consequent vast design spaces have made it difficult and time-consuming to explore the best configuration for them. Design space exploration (DSE) refers to systematic analysis and pruning of unwanted design points based on parameters of interest. DSE requires analysis and estimation of performance criteria of design points. A more accurate estimation produces a more efficient target design. A typical estimation method is machine learning approaches based on statistical inference, also known as empirical modeling, which requires only a limited number of simulations. Undoubtedly, an empirical model finds the optima much faster than using cycle-accurate simulations and is much more accurate than employing analytical models. For that purpose, our paper proposes a general methodology and a framework to find an appropriate and most accurate empirical model to estimate the performance of general-purpose or embedded multiprocessors running multithreaded workloads. This framework consists of three main steps: (1) Workload characterization and clustering, (2) Finding optimal model, and (3) Estimating the performance of a new workload outside the training set. These optimal performance prediction models could be utilized in the process of exploring the architectural design space. An experimental case is also tested using this framework for feasibility purposes. Validation experiments show MAEs less than 10% for this case.