Fast asynchronous algorithm for linear feature extraction on IBM SP-2

Abstract

In this paper, we present a fast parallel implementation of linear feature extraction on IBM SP-2. We first analyze the machine features and the problem characteristics to understand the overheads in parallel solutions to the problem. Based on these, we propose an asynchronous algorithm which enhances processor utilization and overlaps communication with computation by maintaining algorithmic threads in each processing node. Our implementation shows that, given a 512 × 512 image, the linear feature extraction task can be performed in 0.065 seconds on a SP-2 having 64 processing nodes. A serial implementation takes 3.45 seconds on a single processing node of SP-2. A previous implementation on CM-5 takes 0.1 second on a partition of 512 processing nodes. Experimental results on various sizes of images using 4, 8, 16, 32, and 64 processing nodes are also reported.