Report Number: CS-TR-86-1119
Institution: Stanford University, Department of Computer Science
Title: Simulation of an Ultracomputer with Several 'Hot Spots'
Author: Rosenblum, David S.
Author: Mayr, Ernst W.
Date: June 1986
Abstract: This report describes the design and results of a time-driven simulation of an Ultracomputer-like multiprocessor in the presence of several "hot spots," or memory modules which are frequent targets of requests. Such hot spots exist during execution of parallel programs in which the several threads of control synchronize through manipulation of a small number of shared variables. The simulated system is comprised of N processing elements (PEs) and N shared memory modules connected by an N x N buffered, packet-switched Omega network. The simulator was designed to accept a wide variety of system configurations to enable observation of many different characteristics of the system behavior. We present the results of four experiments: (1) General simulation of several 16-PE configurations, (2) General simulation of several 512-PE configurations, (3) Determination of critical queue lengths as a function of request rate (512 PEs) and (4) Determination of the effect of hot spot spacing on system performance (512 PEs).