A comparative analysis of different arbitration protocols for multiple-bus multiprocessors

Earlier performance studies of multiple-bus multiprocessor systems assume a random selection of competing requests for bus assignment and ignore the effects of realistic bus arbitration schemes on the performance of such systems. In this paper, we present performance analysis of the multiple-bus systems with different arbitration protocols. The priority protocols considered are random selection, fixed priority, rotating priority, round-robin and FIFO. Analytical models are developed for each of these five different priority protocols. Each of our analyses models exactly the behavior of the corresponding priority protocol with little computation cost. The analytical models are validated through extensive simulations and are then used to carry out performance analysis and comparison of different priority protocols. Numerical results obtained from our models show that the round-robin protocol performs the best among the five protocols in the system with a few buses.