A couple of important annoucements I did not make in class:
1. The first time you try to run MPI, you may get some errors
and see no output.
In that case, you need to run the
% kinit
unix command (% is the unix prompt), which will request your password,
and then will allow mpi to open remote processes and read/write/etc.
You will only need to run this command at most once a week
(and only if you want to run MPI).
2. It is important to get a set of workstations that are up and connected,
in order to build a machinefile like the file 'm' in the examples.
To get a good list of workstations, copy the files
/u/ccc/bin/teachwsload
and
/u/ccc/bin/teachwsload-sorted
in your directory, and run
% teachwsload-sorted
This will give you the 32 least loaded (but up and connected) workstations.
Use their names to build an m file.
If you need more, give
% teachwsload-sorted 64
to get 64 of them, or whatever number you need.
There are about 200 workstations, but I suggest to be a bit
"polite" to other students...
Even if one workstation in the file m is not up and/or connected,
and even if you do not need that workstation, mpi will not run.
Make sure all workstations you use in the m file are up and connected.
Other things I mentioned in class:
3. Copy test0c1.c test1c.c test3c.c Makefile second5.c
from /u/ccc/mpi/examples
compile and run each test, so that you make sure you can run MPI.
If you get lots of warnings, sorry, these come from the X server,
and the sys admins could not get rid of them.
But the output does show after these warnings.
See also the file m in the same directory, but preferably, do not copy,
build your own as above.