How Much Does Network Contention Affect Distributed Shared Memory Performance?

: Many research results in recent years have focused on the design of distributed shared memory (DSM) systems. However, most of these results are centered around either careful design of node controllers or cache coherence protocols. While evaluating these designs, simplified models of networks (constant network latency or average latency based on the network size) are typically used. Such models completely ignore network contention and thus, do not capture the latency of remote memory references accurately. While this approach may seem reasonable for designing better node architectures or coherency protocols, it serves poorly for understanding and solving the network latency bottleneck problem. In order to help network designers to design better networks for DSM systems, in this paper, we focus on two major goals: 1) to estimate the impact of network link contention and network interface contention on the overall performance of DSM applications and 2) to study the impact of critical a..