Optimal sorting algorithms on incomplete meshes with arbitrary fault patterns

Abstract

In this paper we propose simple and efficient algorithms for sorting on incomplete meshes. No hardware redundancy is required and no assumption is made about the availability of a complete submesh. The proposed robust sorting algorithms are very efficient when only a few processors are faulty and degrade gracefully as the number of faults increases. In particular we show that 1-1 sorting (1 key per healthy processor) in row-major or snakelike row-major order can be performed in 3n+o(n) communication and comparison steps on an n/spl times/n incomplete mesh that has an arbitrary pattern of o(/spl radic/n) faulty processors. This is the fastest algorithm reported thus far for sorting in row-major and snakelike row-major orders on faulty meshes and the time complexity is quite close to its lower bound.