Hi Team,

I am using MPICH 3.0.4.

My top level script invokes a ‘batch script’ in background and then runs my mpi-program using mpiexec.

I run this top-level script in background mode ( please check details later).

It seems once I invoke the mpiexec, my batch-script execution is suspended.

I tried OpenMPI and they do not have the issue.

I have attached 3 files.

1> run.sh : run script to run the top-level program

2> background.sh : invoked from run.sh as a background job. Just prints something on a while loop

3> myprog.c : simple MPI program which just waits on a loop

Compile step : mpicc myprog.c à a.out

#! /bin/bash

./background.sh &

mpiexec  -n 1 ./a.out 

To reproduce :

Shell >> ./run.sh &

Shell >> jobs

[1]  + Suspended (tty input)         ./run.sh

Here the background.sh is suspended. However,  a.out keeps running.

If I change the script so that mpiexec takes input from /dev/null, then the issue is resolved.

#! /bin/bash

./background.sh &

mpiexec  -n 1 ./a.out  < /dev/null

It seems to be a MPICH specific issue.

Could you please have a look and file a bug for this.

Thanks,

Hirak