A LINK-DISJOINT SUBCUBE FOR PROCESSOR ALLOCATION IN HYPERCUBE COMPUTERS

We propose a new type of subcubes, called link-disjoint subcubes (LS), which can be used for the subcube allocation problem in hypercube com puters. A link-disjoint subcube is not a contiguous subcube as in the previous schemes, but this subcube still has no common communication l ink with any other subcubes. When link-disjoint subcubes are used, the performance degradation caused by non-contiguous processor allocation is lower than 1.0% in many cases. With the availability of link-disjo int subcubes, there are [n/2](n-2)C(k-1)2(n-k) k-dimensional LSs recog nizable in an n-dimensional hypercube. The number of all the recogniza ble subcubes under our allocation scheme is ([n/2](n - k)k + n(n - 1)) /n(n - 1) times that under the previous schemes. For example, the numb er of all the recognizable subcubes is at maximum 2.39 times that of c ontiguous subcubes in 10-dimensional hypercube computers, Through simu lation, the performance of our scheme is measured and compared to the previous schemes in terms of processor utilization and waiting delay. It has been shown through simulation that the LSs increase the perform ance of our allocation scheme.