That's not quite right - a call to MPI-finalize does not terminate any 
processes. 

If you're seeing this kind of instability, check the usual suspects such as 
ensuring you have a totally homogeneous environment (same OS, same version of 
OMPI, etc). 

Sent from my PDA. No type good. 

On Feb 1, 2011, at 4:03 AM, "David Zhang" <solarbik...@gmail.com> wrote:

> According to the mpi_finalize documentation, a call to mpi_finalize terminate 
> all processes.  I have ran into this problem before where one process calls 
> mpi_finalize before other processes reach the same line of code and cause 
> errors/hang ups.  Put a mpi_barrier(mpi_comm_world) before mpi_finalize would 
> do the trick.
> 
> On Mon, Jan 31, 2011 at 11:40 PM, abc def <cannonj...@hotmail.co.uk> wrote:
> Hello,
> 
> I'm having trouble with some MPI programming in Fortran, using openmpi.
> It seems that my program doesn't work unless I print some unrelated text to 
> the screen. For example, if I have this situation:
> 
> *** hundreds of lines cut ***
> IF (irank .eq. 0) THEN
>     CALL print_results1(variable)
>     CALL print_results2(more_variable)
> END IF
> print *, "done", irank
> CALL MPI_FINALIZE(ierr)
> END PROGRAM calculation
> 
> The results are not printed unless I include this "print done irank" 
> penultimate line.
> Also, despite seeing that all ranks reach the print statement, the program 
> hangs, as if they have not all reached MPI_FINALIZE.
> 
> Can anyone help me? Why does it do this?
> 
> I also had many times where the program would crash if I didn't include a 
> print statement in a loop. I've been doing Fortran programming for a while, 
> and this is my nightmare debugging scenario since I've never been able to 
> figure out why the simple printing of statements magically fixes the program, 
> and I usually end up having to go back to a serial solution, which is really 
> slow.
> 
> If anyone might be able to help me, I would be really really grateful!!
> 
> Thank you.
> 
> Tom
> 
> 
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> 
> 
> -- 
> David Zhang
> University of California, San Diego
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