Evaluation of Dual Ported Memories from the Task Level

An architecture, which is a hybrid of local memory and shared memory, is described in this report: it uses dual ported memories (DPMs), each accessed by two processors. Each processor is connected to a number of DPMs. The profit that is gained by using a DPM as a shared memory between two processors appears from task allocation results: task transport costs are avoided when a task, newly created in DPM d by one of d’s two processors, is allocated to the other processor at d. For a number of task allocation strategies, simulation studies show that the fraction of the tasks that benefit from this optimisation decreases with the number of processors in the multiprocessor. For larger numbers of processors, this fraction is considerably higher than the fraction under random allocation.