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
cause?
#! /bin/sh
# MPIRUN for MPICH
# (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 . filename.sh 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"
DEFAULT_DEVICE=ch_p4
RSHCOMMAND="/usr/bin/ssh"
SYNCLOC=/bin/sync # *<---------- WE DISABLED THIS WITH A #COMMENT#*
CC="cc"
COMM=
GLOBUSDIR=@GLOBUSDIR@
CLINKER="cc"
prefix=/cluster/cairo/software/mpich-1.2.5.2
bindir=/cluster/cairo/software/mpich-1.2.5.2/bin
# This value for datadir is the default value setup by configure
datadir=/cluster/cairo/software/mpich-1.2.5.2/share
DEFAULT_MACHINE=ch_p4
DEFAULT_ARCH=LINUX
# Derived variables
MPIRUN_BIN=$bindir
MPIRUN_HOME=$MPIRUN_BIN
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)
polling_mode=1
# 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)
#
hasprinthelp=1
. $MPIRUN_HOME/mpirun.args
argsset=1
#
# Jump to the correct code for the device (by pseudo machine)
#
mpirun_version=""
case $machine in
ch_cmmd)
mpirun_version=$MPIRUN_HOME/mpirun.ch_cmmd
;;
ibmspx|ch_eui|ch_mpl)
mpirun_version=$MPIRUN_HOME/mpirun.ch_mpl
;;
anlspx)
mpirun_version=$MPIRUN_HOME/mpirun.anlspx
;;
ch_meiko|meiko)
mpirun_version=$MPIRUN_HOME/mpirun.meiko
;;
cray_t3d|t3d)
mpirun_version=$MPIRUN_HOME/mpirun.t3d
;;
ch_nc)
mpirun_version=$MPIRUN_HOME/mpirun.ch_nc
;;
paragon|ch_nx|nx)
mpirun_version=$MPIRUN_HOME/mpirun.paragon
;;
inteldelta)
mpirun_version=$MPIRUN_HOME/mpirun.delta
;;
i860|ipsc860)
mpirun_version=$MPIRUN_HOME/mpirun.i860
;;
p4|ch_p4|sgi_mp)
mpirun_version=$MPIRUN_HOME/mpirun.ch_p4
;;
gm|ch_gm|myrinet)
mpirun_version=$MPIRUN_HOME/mpirun.ch_gm
;;
execer)
mpirun_version=$MPIRUN_HOME/mpirun.execer
;;
ch_shmem|ch_spp|smp|convex_spp)
# sgi_mp is reserved for the p4 version
mpirun_version=$MPIRUN_HOME/mpirun.ch_shmem
;;
ksr|symm_ptx)
mpirun_version=$MPIRUN_HOME/mpirun.p4shmem
;;
ch_tcp|tcp)
mpirun_version=$MPIRUN_HOME/mpirun.ch_tcp
;;
globus)
mpirun_version=$MPIRUN_HOME/mpirun.globus
;;
*)
#
# This allows us to add a device without changing the base mpirun
# code
if [ -x $MPIRUN_HOME/mpirun.$device ] ; then
mpirun_version=$MPIRUN_HOME/mpirun.$device
elif [ -x $MPIRUN_HOME/mpirun.$default_device ] ; then
mpirun_version=$MPIRUN_HOME/mpirun.$default_device
device=$default_device
else
echo "Cannot find MPIRUN machine file for machine $machine"
echo "and architecture $arch ."
if [ -n "$device" ] ; then
echo "(Looking for $MPIRUN_HOME/mpirun.$device)"
else
echo "(No device specified.)"
fi
# . $MPIRUN_HOME/mpirun.default
exit 1
fi
;;
esac
exitstatus=1
if [ -n "$mpirun_version" ] ; then
if [ -x $mpirun_version ] ; then
# The mpirun script *must* set exitstatus (or exit itself)
. $mpirun_version
else
echo "$mpirun_version is not available."
exit 1
fi
else
echo "No mpirun script for this configuration!"
exit 1
fi
exit $exitstatus
