Open MPI logo

Open MPI User's Mailing List Archives

  |   Home   |   Support   |   FAQ   |   all Open MPI User's mailing list

Subject: Re: [OMPI users] Introduce myself.
From: brian janus (brian.janus_at_[hidden])
Date: 2008-04-06 14:45:15

I'm new here so forgive me if I ask any dumb questions. But the first
question I have concerns the mpirun script below.

My question is, what does the SYNCLOC=/bin/sync line for in the script below
do, and what complications could arise (if any), from disabling this option
by commenting out the line like #SYNCLOC=/bin/sync. In some code we are
running, we have found that disabling this option allows high priority jobs
to complete in only a couple of seconds, whereas before they would take
several minutes.

What does SYNCLOC do, and if its disabled, what kind of problems might that

#! /bin/sh

# (Don't change the above line - we use it to identify MPICH mpirun as
# opposed to others (e.g., SGI's mpirun)
# This script tries to start jobs on whatever kind of machine you're on.
# Strategy - This program is built with a default device it uses in
# certain ways. The user can override this default from the command line.
# This sh script is designed to use other scripts to provide the commands
# to run each system, using the . mechanism
# Debuggers should be handled by running
# mpirun.db.<debugger_name>
# e.g., mpirun.db.gdb or mpirun.db.xxgdb.
# This will allow users to add there own debuggers
# (with -debug=<debugger_name>)
# Set default variables
AUTOMOUNTFIX="sed -e s@/tmp_mnt/@/@g"
SYNCLOC=/bin/sync # *<---------- WE DISABLED THIS WITH A #COMMENT#*
# This value for datadir is the default value setup by configure

# Derived variables
MPIVERSION="1.2.5 (release) of : 2003/01/13 16:21:53"

#set verbose
# Local routines
# End of routine

# Special, system specific values
# polling_mode is for systems that can select between polling and
# interrupt-driven operation. Currently, only IBM POE is so supported
# (TMC CMMD has some support for this choice of mode)

# Parse command line arguments
# The ultimate goal is to determine what kind of parallel machine this
# is we are running on. Then we know how to start jobs...
# Process common arguments (currently does ALL, but should pass unrecognized
# ones to called files)
. $MPIRUN_HOME/mpirun.args

# Jump to the correct code for the device (by pseudo machine)
case $machine in
        # sgi_mp is reserved for the p4 version
        # This allows us to add a device without changing the base mpirun
        # code
        if [ -x $MPIRUN_HOME/mpirun.$device ] ; then
        elif [ -x $MPIRUN_HOME/mpirun.$default_device ] ; then
            echo "Cannot find MPIRUN machine file for machine $machine"
            echo "and architecture $arch ."
            if [ -n "$device" ] ; then
                echo "(Looking for $MPIRUN_HOME/mpirun.$device)"
                echo "(No device specified.)"
            # . $MPIRUN_HOME/mpirun.default
            exit 1
if [ -n "$mpirun_version" ] ; then
    if [ -x $mpirun_version ] ; then
        # The mpirun script *must* set exitstatus (or exit itself)
        . $mpirun_version
               echo "$mpirun_version is not available."
            exit 1
    echo "No mpirun script for this configuration!"
    exit 1
exit $exitstatus

On Sun, Apr 6, 2008 at 10:48 AM, Davi Vercillo C. Garcia <
davivercillo_at_[hidden]> wrote:

> Brock,
> On Sun, Apr 6, 2008 at 12:39 AM, Brock Palen <brockp_at_[hidden]> wrote:
> > The best online way to learn MPI I have ever found was the NCSA class
> > here:
> >
> >
> Thanks a lot !!!
> --
> Davi Vercillo Carneiro Garcia
> Universidade Federal do Rio de Janeiro
> Departamento de Ciência da Computação
> "Good things come to those who... wait." - Debian Project
> "A computer is like air conditioning: it becomes useless when you open
> windows." - Linus Torvalds
> "Há duas coisas infinitas, o universo e a burrice humana. E eu estou
> em dúvida quanto o primeiro." - Albert Einstein
> _______________________________________________
> users mailing list
> users_at_[hidden]