On detecting and using memory phases in multimedia systems

Many multimedia applications exhibit a phasic behavior. Phasic behavior of applications has been studied primarily focused on code execution. However, temporal variation in an application's memory usage can deviate from its program behavior, providing opportunities to exploit these memory phases to enable more efficient use of on-chip memory resources. In this work, we define memory phases as opposed to program phases, and illustrate the potential disparity between them. We propose mechanisms for light-weight online memory-phase detection. Additionally, we demonstrate their utility by deploying these techniques for sharing distributed on-chip Scratchpad Memories (SPMs) in multi-core platforms. The information gathered during memory phases are used to prioritize different memory pages in a multi-core platform without having any prior knowledge about running applications. By exploiting memory-phasic behavior, we achieved up to 45% memory access latency improvement on a set of multimedia applications.