Dynamic phase-based tuning for embedded systems using phase distance mapping

Phase-based tuning specializes a system´s tunable parameters to the varying runtime requirements of an application´s different phases of execution to meet optimization goals. Since the design space for tunable systems can be very large, one of the major challenges in phase-based tuning is determining the best configuration for each phase without incurring significant tuning overhead (e.g., energy and/or performance) during design space exploration. In this paper, we propose phase distance mapping, which directly determines the best configuration for a phase, thereby eliminating design space exploration. Phase distance mapping applies the correlation between a known phase´s characteristics and best configuration to determine a new phase´s best configuration based on the new phase´s characteristics. Experimental results verify that our phase distance mapping approach determines configurations within 3% of the optimal configurations on average and yields an energy delay product savings of 26% on average.