[gpfsug-discuss] Friday MPI fun?

[Chair GPFS UG]

Allo all,

  I'm attempting to cheat.  As per-usual, cheating takes more time than
'Doing It Properly' - but it is vastly more fun.

So without setting up Grid or Moab etc, I need to pin processes to a cpu.
 I.E. on Linux: taskset blah blah.
I could write a small housekeeping script which RR new spawned processes
across CPUs using taskset, but I was wondering if OpenMPI could be a good
way to go.

So:

I have a non-MPI application X.
Which is spawned and forked by a parent process into its own process group.
This can occur at any time, however there will only ever be a maximium N of
appl X.

Using mpirun it appears that you can set off parallel instances of a
non-MPI application:

mpirun -np 4 applicationX

However, really what I'm requiring to do is say:
  Max slots = N (which I can define in the mpi hostfile).

mpirun -np 1 applicationX
mpirun -np 1 applicationX (started at a random future time)
mpirun -np 1 applicationX (started at a random future time)
mpirun -np 1 applicationX (started at a random future time)

Each being automatically pinned to a CPU, but I'm fairly convinced this is
not the way MPI works.
Would it do what I'm after?

Does anyone know of a better way?

Jez
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://gpfsug.org/pipermail/gpfsug-discuss_gpfsug.org/attachments/20131025/37f6a4c9/attachment.htm>