The Circulating Processor Model of Parallel Systems

This paper introduces the circulating processor model for parallel computer systems. The circulating processor model is a product form queuing network model where the processors are allowed to circulate between the parallel applications instead of the more traditional circulating task model. Certain behaviors of parallel systems are better captured using this new approach. The circulating processor model may be load dependent or load dependent. The load dependent circulating processor model is exact for systems which contain a single parallel application. An exact error is calculated for the load independent circulating processor model for systems which contain a single parallel application. The load dependent circulating processor model is a good approximation to the actual system in the case of multiple parallel applications. The load dependent circulating processor model compares favorably to the traditional circulating task model

The evaluation of computer performance by means of state-dependent queueing network models

Imperial Users onl

On closed queueing networks with mixed preemptive resume priority servers.

This paper discusses a typical closed queueing network model in which multiple preemptive resume servers are present with different priority structures at each priority node. An algorithm is developed that is applicable for the three-node two-class model and results are compared to point estimates obtained from simulation. The algorithm is partly based on the Delay/MVA algorithm developed by Bondi and Chuang, because of the accuracy with which instant arrival queue lengths at fcfs servers are calculated. Results are also compared with results obtained from the Shadow Approximation.Networks;