1. A multi-processor processing system comprising: a shared memory for being accessed by multiple devices; a plurality of processing devices external to said shared memory having respective dedicated memory management units for translating virtual memory addresses, used internally by the processing devices to access locations in said shared memory, to physical memory addresses corresponding to shared memory locations, where the dedicated memory management units each translate according to tables maintained separately from other of the dedicated memory management units; and a global unified memory management system for allocating the shared memory to a plurality of tasks executed on the processing devices, to allocate one or more of the tasks with areas of said shared memory separate from address spaces of shared memory allocated to other tasks.