An Efficient Turning Busy List Sub-Mesh Allocation Strategy for 3D Mesh Connected Multicomputers

In this paper, a fast and efficient busy-list sub-mesh allocation strategy, referred to as Turning Busy List (TBL), is suggested for 3D mesh connected multicomputers. Turning means that the orientation of the allocation request is changed when no sub-mesh is available in the requested orientation. The TBL strategy considers only those available free sub-meshes that border from the left on some allocated sub-meshes or have their left boundaries aligned with that of the mesh. Moreover, the TBL strategy uses an efficient scheme to facilitate the detection of such available sub-meshes with low allocation overhead. The basic idea in this strategy is to maintain a list of allocated sub-meshes to determine all the nodes that cannot be used as base nodes for the requested sub-mesh. These nodes are then subtracted from the right border plane of the allocated sub-meshes to find the nodes that can be used as base nodes for the required sub-mesh size. The TBL strategy is able to identify a free sub-mesh of the requested size as long as it exists in the mesh. Results from extensive simulations under various system loads have revealed that the TBL strategy incurs much less allocation overhead than all of the existing contiguous allocation strategies for 3D mesh and delivers competitive performance in terms of parameters such as the average turnaround times and system utilization. Moreover, the time complexity of the TBL strategy is much lower than that of the existing strategies. Keywords-Contiguous Allocation, Turnaround Time, Utilization, Allocation Overhead, Switching Request Orientation, Simulation.