1. A method comprising: allocating a memory region for sharing between a CPU and a graphics processor; assigning said shared memory region a caching attribute favorable to an operating efficiency of said CPU; performing a transition from a first mode wherein said CPU is using said memory region to a second mode wherein said graphics processor is using said memory region; and during said transition from said first mode to said second mode, changing said caching attribute to one favorable to an operating efficiency of said graphics processor.