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.