Maximizing common idle time on multi-core processors with shared memory

Reducing energy consumption is a critical problem in most of the computing systems today. This paper focuses on reducing the energy consumption of the shared main memory in multi-core processors by putting it into sleep state when all the cores are idle. Based on this idea, this work presents systematic analysis of different assignment and scheduling models and proposes a series of scheduling schemes to maximize the common idle time of all cores. An optimal scheduling scheme is proposed assuming the number of cores is unbounded. When the number of cores is bounded, an efficient heuristic algorithm is proposed. The experimental results show that the heuristic algorithm works efficiently and can save as much as 25.6% memory energy compared to a conventional multi-core scheduling scheme.