A Basic-Cycle Calculation Technique for Efficient Dynamic Data Redistribution

Abstract

In this paper, we present basic-cycle calculation technique to efficiently perform the general BLOCK-CYCLE(s) to BLOCK-CYCLE(t) redistribution. In the basic-cycle calculstion, closed from representations for computing source/destination processors of array elements in a basic cycle, which is defined as lcm(s,t)/gcd(s,t), are derived. To evaluate the performance of the basic-cycle calculation, we have implemented the basic-cycle calculation on an IBM SP2 parallel machine along with the multi-phase method [7]. The experimental results show that the basic-cycle calculation outperforms the two-strage multi-phase method for the case where s is not divisible by t and vice versa for all test samples. For the case where s is divisible by t or vice versa, the basic-cycle calculation outperforms the two-strage multi-pfase method when the array size is over a threshold. However, in this case, the one-stage multi-phase method outperforms the basic-cycle calculation for all test samples.