Modeling and measuring hot spots on MIN-based and HR-based shared-memory architectures

In this paper, we present a comparative performance evaluation of hot spot effects on the MIN-based and HR-based shared-memory architectures. Analytical models are described for understanding network differences and for evaluating hot spot performance on both architectures. The analytical comparisons indicate that HR-based architectures have the potential to handle various contentions caused by hot spots more efficiently than MIN-based architectures. Although there is no analytical and experimental evidence that the tree saturation phenomenon occurs in non-blocking MIN architectures, remote accesses to both hot and cool memory modules are considerably slowed down, and overall performance is significantly degraded. Intensive performance measurements on hot spots have been conducted on the BBN TC2000 (MIN-based) and the KSR1 (HR-based) machines. Performance experiments were also conducted on the practical experience of hot spots with respect to synchronization lock and barrier algorithms. The experimental results support the analytical models, and present practical observations and an evaluation of hot spots on the two types of architectures