A New Methodology to Computer Deadlock-Free Routing Tables for Irregular Networks

TLDR: A new methodology to compute deadlock-free routing tables for NOWs is proposed, based on generating an underlying acyclic connected graph from the network graph and assigning a sequence number to each switch, which is used to remove cyclic dependencies.

Abstract: Networks of workstations (NOWs) are being considered as a cost-effective alternative to parallel computers Many NOWs are arranged as a switch-based network with irregular topology, which makes routing and deadlock avoidance quite complicated Current proposals use the up*/down* routing algorithm to remove cyclic dependencies between channels and avoid deadlock However, routing is considerably restricted and most messages must follow non-minimal paths, increasing latency and wasting resources In this paper, we propose a new methodology to compute deadlock-free routing tables for NOWs The methodology tries to minimize the limitations of the current proposals in order to improve network performance It is based on generating an underlying acyclic connected graph from the network graph and assigning a sequence number to each switch, which is used to remove cyclic dependencies Evaluation results show that the routing algorithm based on the new methodology increases throughput by a factor of up to 2 in large networks, also reducing latency significantly