Parallel Environment for AIX 5L V4.1
Hitchhiker's Guide

Mostly harmless

In an early edition of the Hitchhiker's Guide to the Galaxy, Earth's entry in the guide is only one word -- harmless. After 15 years of research on Earth, Ford Prefect, a writer for the guide, substantially lengthens the entry to read "mostly harmless". Arthur Dent, the Earth man who was expecting to have a relaxing day and instead had his planet blown up to make way for a hyperspace bypass, is appalled that the guide affords only these two words. Ford tells him, "Well, that's the way it is; we're on a different scale now".

Going from serial to parallel programming means that you too are on a different scale now. In this chapter, we alert you to some of the things you need to pay attention to as you create your parallel programs. In particular, we provide information on creating a safe (mostly harmless) MPI program. Much of the information presented here was shamelessly lifted from MPI: A Message-Passing Interface Standard, Version 1.1 which is available from the University of Tennessee (http://www.mpi-forum.org/). For more information, you may want to refer to that document.