Dynamic Reconfiguration of Two-Level Cache Hierarchy in Real-Time Embedded Systems

System optimization techniques based on efficient dynamic reconfiguration have been widely adopted in recent years. Cache reconfiguration is a promising optimization technique for reducing memory hierarchy energy consumption with little or no impact on overall system performance. While cache reconfiguration is successful in desktop-based and embedded systems, it is not directly applicable in real-time systems due to timing constraints. Existing scheduling-aware cache reconfiguration techniques consider only one-level cache. It is a major challenge to dynamically tune multi-level caches since the exploration space is prohibitively large. This paper efficiently integrates cache reconfiguration in real-time systems with a unified two-level cache hierarchy. We propose a set of exploration heuristics for our static analysis which effectively reduces the exploration time while keeps the generated profile results beneficial to be leveraged during runtime. Our experimental results have demonstrated 40-58% energy savings with minor impact on performance.