Help! How to compile parallel C program with MPI codes?

[kelvin490]

I have a simple testing program like this:

/*The Parallel Hello World Program*/
#include <stdio.h>
#include <mpi.h>

main(int argc, char **argv)
{
int node;

MPI_Init(&argc,&argv);
MPI_Comm_rank(MPI_COMM_WORLD, &node);

printf("Hello World from Node %d\n",node);

MPI_Finalize();
}

My program is, I can't compile this program using gcc, and I can't find something like pgcc in ubuntu. How should I compile this program? After compiling, what should I do to run this program?

Can I use something like mpirun to run it? I want to try to use both cores of my computer to run it and make it shows Node 1 also besides Node0.

Thank you.

[Rubberman]

You need to install MPI on your Ubuntu system. Try "sudo apt-get install openmpi-devel".

[abarclay]

You probably don't have mpi installed.... Here is how I installed it just now....

I downloaded the mpi source from here:
MPICH2 : High-performance and Widely Portable MPI

Extracted it on my centos 6 system and did:
$ ./configure --disable-fc --disable-fc77 --disable-cxx
$ make
# make install

Now, I put your program into a file called par.c and tried to compile it:

$ mpicc -o par.out par.c

hmmm, seems to work.

$ now let me see if I can run it.

$ mpirun -np 1 ./par.out
Hello World from Node 0

Seems to work.

[kelvin490]

In my case, it is:
$ mpirun -np 1 ./try.exe
mpiexec_ubuntu: cannot connect to local mpd (/tmp/mpd2.console_shsh); possible causes:
1. no mpd is running on this host
2. an mpd is running but was started without a "console" (-n option)
In case 1, you can start an mpd on this host with:
mpd &
and you will be able to run jobs just on this host.
For more details on starting mpds on a set of hosts, see
the MPICH2 Installation Guide.

the mpicc can compile but seems still cannot use mpirun