Level-wise Scheduling Algorithm for Fat Tree Interconnection Networks

This paper presents an efficient hardware architecture for scheduling connections on a fat-tree interconnection network for parallel computing systems. Our technique utilizes global routing information to select upward routing paths so that most conflicts can be resolved. Thus, more connections can be successfully scheduled compared with a local scheduler. As a result of applying our technique to two-level, three-level and four-level fat-tree interconnection networks of various sizes in the range of 64 to 4096 nodes, we observe that the improvement of schedulability ratio averages 30% compared with greedy or random local scheduling. Our technique is also scalable and shows increased benefits for large system sizes