Deriving analytical models from a limited number of runs

Publisher Summary This chapter describes a methodology to derive a simple characterization of a parallel program and models of its performance on target architecture. The approach starts from an instrumented run of the program to obtain a trace. A simple linear model of the performance of the application as a function of architectural parameters is derived by fitting the results of a bunch of simulations based on the trace. The approach, while being very simple, is able to derive analytic models of execution time as a function of parameters, such as processor speed, network latency, or bandwidth without even looking at the application source. It shows how it is possible to extract from one trace detailed information about the intrinsic characteristics of a program. A relevant feature of this approach is that, a natural interpretation can be given to the different factors in the model. To derive models of other factors, such as number of processors, several traces are obtained and the values obtained with them extrapolated.