Cache scheme of shared-buffer mappings for energy-efficiency of mobile devices

The repetitive mapping and unmapping operations of shared buffers, which are used for data sharing among applications and devices, incur significant processing overhead. Thus, a significant amount of energy is consumed during video playback, especially when physical address space becomes heavily fragmented after a large number of application instances. A caching scheme that preserves mapping information of the shared buffer for later use of the same buffer mapping is proposed. The evaluation shows that the proposed scheme reduces processor utilisation by ~64% and energy consumption by ~17% during video playback compared with that of commercial smartphone systems.