Performance Improvement of Allocation Schemes for Mesh-Connected Computers

Abstract

Fragmentation is the one of the main problem in scheduling jobs on multicomputer systems. In this paper, we classify the fragmentation problems in multicomputer systems on the basis of their causes. It is noted that among all kinds of fragmentation, physical fragmentation is seldom addressed by contemporary allocation schemes. Two novel processor allocation schemes that reduce physical fragmentation for the mesh-connected multicomputers are proposed to improve the performance of the mesh-connected computers. The first scheme allows jobs to be executed on a reduced size submesh adaptively. The second scheme allocates jobs on noncontiguous processors if fragmentation prevents a job from being allocated. Extensive simulations indicate significant performance gain by using these two schemes. The performance improvement along with flexibility of implementation make these two allocation schemes suitable for mesh-connected multicomputers.