Initialize the MPI execution environment
- argc - Pointer to the number of arguments
- argv - Pointer to the argument vector
Command line arguments
MPI specifies no command-line arguments but does allow an MPI
implementation to make use of them.
- -mpiqueue - print out the state of the message queues when MPI_FINALIZE
is called. All processors print; the output may be hard to decipher. This
is intended as a debugging aid.
- -mpiversion - print out the version of the implementation (not of MPI),
including the arguments that were used with configure.
- -mpinice nn - Increments the nice value by nn (lowering the priority
of the program by nn). nn must be positive (except for root). Not
all systems support this argument; those that do not will ignore it.
- -mpedbg - Start a debugger in an xterm window if there is an error (either
detected by MPI or a normally fatal signal). This works only if MPICH
was configured with -mpedbg.
- -mpipktsize nn - Set the message length where the ADI changed to
the long message protocol to nn. This only works if MPICH was
configured with -var_pkt.
The following options are available only on the Chameleon device and
devices built with debugging code. Normally, these should only be used
by MPICH implementors when debugging new ports.
- -mpichdebug - Print out the Chameleon device operations
- -mpidbfile filename - Like mpichdebug, but sends the output to the
specified file. If the filename contains a %d, then that part of
the filename is replaced with the rank in MPI_COMM_WORLD. For example,
writes to log.0, log.1, etc.
- -mpichmemdebug - (Chameleon device only) Print out a list of unreclaimed
memory. This requires that MPI be built with the -DMPIR_DEBUG_MEM
switch. This is intended for debugging the MPI implementation itself.
- -mpimem - If MPICH was built with -DMPIR_DEBUG_MEM, this checks all
malloc and free operations (internal to MPICH) for signs of injury
to the memory allocation areas.
- -mpichmsg - Print out the number of messages
received, by category, when the program exits.
- -mpidb options - Activate various debugging options. Some require
that MPICH have been built with special options. These are intended
for debugging MPICH, not for debugging user programs. The available
mem - Enable dynamic memory tracing of internal MPI objects
memall - Generate output of all memory allocation/deallocation
ptr - Enable tracing of internal MPI pointer conversions
rank n - Limit subsequent -mpidb options to on the process with
the specified rank in MPI_COMM_WORLD. A rank of -1
selects all of MPI_COMM_WORLD.
ref - Trace use of internal MPI objects
reffile filename - Trace use of internal MPI objects with output
to the indicated file
trace - Trace routine calls
Note that the Fortran binding for this routine has only the error return
Because the Fortran and C versions of MPI_Init are different, there is
a restriction on who can call MPI_Init. The version (Fortran or C) must
match the main program. That is, if the main program is in C, then
the C version of MPI_Init must be called. If the main program is in
Fortran, the Fortran version must be called.
On exit from this routine, all processes will have a copy of the argument
list. This is not required by the MPI standard, and truely portable codes
should not rely on it. This is provided as a service by this
implementation (an MPI implementation is allowed to distribute the
command line arguments but is not required to).
Command line arguments are not provided to Fortran programs. More
precisely, non-standard Fortran routines such as getarg and iargc
have undefined behavior in MPI and in this implementation.
The MPI standard does not say what a program can do before an MPI_INIT or
after an MPI_FINALIZE. In the MPICH implementation, you should do
as little as possible. In particular, avoid anything that changes the
external state of the program, such as opening files, reading standard
input or writing to standard output.
The MPI standard requires that all signals used be documented. The MPICH
implementation itself uses no signals, but some of the software that MPICH
relies on may use some signals. The list below is partial and should
be independantly checked if you (and any package that you use) depend
on particular signals.
IBM POE/MPL for SP2
SIGHUP, SIGINT, SIGQUIT, SIGFPE, SIGSEGV, SIGPIPE, SIGALRM, SIGTERM,
SIGQUIT, SIGILL, SIGFPE, SIGBUS, SIGSEGV, SIGSYS
Intel Paragon (ch_nx and nx device)
Shared Memory (ch_shmem device)
Note that if you are using software that needs the same signals, you may
find that there is no way to use that software with the MPI implementation.
The signals that cause the most trouble for applications include
SIGIO, SIGALRM, and SIGPIPE. For example, using SIGIO and
SIGPIPE may prevent X11 routines from working.
All MPI routines (except MPI_Wtime and MPI_Wtick) return an error value;
C routines as the value of the function and Fortran routines in the last
argument. Before the value is returned, the current MPI error handler is
called. By default, this error handler aborts the MPI job. The error handler
may be changed with MPI_Errhandler_set; the predefined error handler
MPI_ERRORS_RETURN may be used to cause error values to be returned.
Note that MPI does not guarentee that an MPI program can continue past
- MPI_SUCCESS - No error; MPI routine completed successfully.
- MPI_ERR_OTHER - This error class is associated with an error code that
indicates that an attempt was made to call MPI_INIT a second time.
MPI_INIT may only be called once in a program.