New MPI user question. RRS feed

  • Question

  • I have an HP laptop computer with dual core CPU's and 6 GB of RAM, running the MS Vista 64-bit operating system and
    the Intel 64-bit FORTRAN compiler, version 10.0.027.  I am trying to follow the MPI FORTRAN example codes in the book,
    "Using MPI:  Portable Parallel Programming with the Message-Passing Interface," 2nd ed., by W. Gropp, et. al.  Specifically,
    I am trying to run the simple FORTRAN program shown on page 25 which calculates pi, CalcPi.  I have successfully, I think, loaded,
    compiled, and linked this short FORTRAN program with the MPI library--no errors.  When I run it, just by initiating the
    CalcPi.exe, as in C:> CalcPi  the program runs and produces the correct pi result; however, the variable "numprocs," which is
    the number of processes used to do the calculation, is always 1, no matter how many integration steps I request.  Doing more
    research, I found that I was not properly starting this MPI code:  I should be initiating the command:
    C:> mpiexec -n 4 CalcPi.exe   if I wanted more than 1 process (4 in this case).  However, when I run this, I get this error message:

    Error while connecting to host.  No connection could be made because the target machine actively refused it.  (10061)
    Connect on sock (host=Owner-PC, port=8676) failed, exhaused [sic] all end points
    Unable to connect to 'Owner-PC:8676', sock error:  Error = -1

    I am the administrator on this laptop, and I am not trying to connect to another machine, to my knowledge.  So, what am I doing wrong?
    As I say, when I run CalcPi.exe as C:> CalcPi  all appears to run well, except that "numprocs" always equals 1 no matter how many
    integrations steps I request, and I have gone as high as 1 billion.
    Wednesday, October 14, 2009 5:51 PM


  • Hi,

    Are you using the MPICH2 or the MSMPI stack?
    Please make sure that you don't mix MPICH2 and MSMPI dlls/mpiexec/smpd.

    Wednesday, October 28, 2009 6:34 PM