Process Scheduling - based Energy Management for Bank - aware Memory System ⋆

With its growing capacity and density, off-chip memory consumes a considerable amount of energy in the mobile system, so there are strong demands for energy-efficient techniques. Memory manufacturers provide several operating modes with different power requirements. To explore these modes for energy saving, the memory has to switch among those modes frequently. However, the mode transition also consumes energy, which poses a threat to the existing power-budget problem. In this paper, we propose an OS-based methodology to reduce the energy overhead caused by memory mode transitions. In particular, we propose an algorithm to optimize the executing order of processes to reduce the number of memory mode transitions as well as to create long idle intervals for energy saving. The capability of the proposed strategy is evaluated through practical platforms, for which we have encouraging results.