[yt-users] --parallel not working for MPT?

Nathan Goldbaum nathan12343 at gmail.com
Thu Sep 26 16:38:03 PDT 2013


Hi Semyeong,

With the MPT module loaded, can you successfully import mpi4py?  yt uses
mpi4py in the background to handle MPI communication.  If you have openmpi
and MPT on the same system, it may be that you installed mpi4py using
openmpi rather than MPT.  When yt tries to import mpi4py, that fails since
openmpi is not available.

Of course if there is only MPT available on your system, my guess is
probably incorrect.

Running the script I've pasted below should expose any issues with mpi4py:

from mpi4py import MPI
import sys

size = MPI.COMM_WORLD.Get_size()
rank = MPI.COMM_WORLD.Get_rank()
name = MPI.Get_processor_name()

sys.stdout.write(“Helloworld! I am process %d of %d on %s.\n” % (rank,
size, name))

Cheers,

Nathan


On Thu, Sep 26, 2013 at 4:32 PM, Semyeong Oh <semyeong.oh at gmail.com> wrote:

> Hi all,
>
> I want to divide ENZO simulation into certain regions, do some operation
> and save some files in parallel. I used parallel_objects for this.
>
> If I use openMPI and do
> $mpirun -np 6 python script.py --parallel
> it works fine.
>
> But if I use MPT(a variety of MPICH, I think) and run the exact same
> command,
> it ignores --parallel and just does things in serial.
>
> Is this expected? I'm new to parallel computation, and kind of stuck here.
> Thanks for your help.
>
> Best regards,
> Semyeong
>
>
>
> _______________________________________________
> yt-users mailing list
> yt-users at lists.spacepope.org
> http://lists.spacepope.org/listinfo.cgi/yt-users-spacepope.org
>
>
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