Emulating cache organizations on real hardware using performance cloning

Abstract

Computer system designers need a deep understanding of end users' workload in order to arrive at an optimum design. Unfortunately, many end users will not share their software to designers due to the proprietary or confidential nature of their software. Researchers have proposed workload cloning, which is a process of extracting statistics that summarize the behavior of users' workloads through profiling, followed by using them to drive the generation of a representative synthetic workload (clone). Clones can be used in place of the original workloads to evaluate computer system performance, helping designers to understand the behavior of users workload on the simulated machine models without the users having to disclose proprietary or sensitive information about the original workload. In this paper, we propose infusing environment-specific information into the clone. This Environment-Specific Clone (ESC) enables the simulation of hypothetical cache configurations directly on a machine with a different cache configuration. We validate ESC on both real systems as well as cache simulations. Furthermore, we present a case study of how page mapping affects cache performance. ESC enables such a study at native machine speed by infusing the page mapping information into clones, without needing to modify the OS or hardware. We then analyze the factors that determine how page mapping impact cache performance, and how various applications are affected differently.