Phase-based Cache Locking for Embedded Systems

Since caches are commonly used in embedded systems, which typically have stringent design constraints imposed by physical size, battery capacity, real-time deadlines, etc., much research focuses on cache optimizations, such as improved performance and/or reduced energy consumption. Cache locking is a popular cache optimization that loads and retains/locks selected memory contents from an executing application into the cache to increase the cache's predictability. Previous work has shown that cache locking also has the potential to improve cache performance and energy consumption. In this paper, we introduce phase-based cache locking, which leverages an application's varying runtime characteristics to dynamically select the locked memory contents to optimize cache performance and energy consumption. Experimental results show that our phase-based cache locking methodology can improve the data cache's miss rates and energy consumption by an average of 24% and 20%, respectively.