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Re: running serpent in parallel

Posted: Thu Mar 27, 2014 2:18 am
by Mohamed Salah
Hi Jaakko,

yes, the MPI_tasks =1
and when the code running it gave me after the serpent logo the " parallel calculation mode available"

but it run individual tasks !?

Re: running serpent in parallel

Posted: Thu Mar 27, 2014 9:51 am
by Jaakko Leppänen
The MPI_TASKS variable shows the number of parallel tasks used for running the calculation, so it seems it was run with a single task only. Did you use mpirun or how did you run Serpent from the command line?

Re: running serpent in parallel

Posted: Thu Mar 27, 2014 8:04 pm
by Mohamed Salah
Hi

I run serpent from command prompt
1st. I am using 32 threading core, not parallel nodes computer
so as I running mcnp using "tasks for parallel threading" this is just notes

In Serpent, In command line I wrote
c:> sss -mpi 16 <input>
I reinstall mpirun and check it , it works
then I cleaning it "orte-clean"
but when I used mpirun -np 4 sss <input>
it run as individuals 4 core too !

do I need to reinstall serpent
or define the file path of the " mpirun" in the header.h file ?
or what can I do
thnx
mohamed

Re: running serpent in parallel

Posted: Sat Mar 29, 2014 12:00 pm
by Jaakko Leppänen
OK, so with
sss -mpi 16 <input>
you get 16 tasks within a single node, but with:
mpirun -np 4 sss <input>
you get 4 tasks each run on a separate node. Is this correct?

To me it seems that the problem is in the initialization of MPI. I believe the mpirun script reads the configuration from file "hostfile", and sets up the tasks accordingly. If the file is missing, there is probably some default configuration that is used. When you run Serpent with the command line option "-mpi", it actually calls mpirun to execute the calculation in parallel. It is possible that in this case the version of mpirun (or hostfile) is different from than what you get when you run mpirun from command line, which would explain the different behavior.

To solve the problem, I suggest you run the calculation directly with mpirun, i.e. withouth using the "-mpi" command line option, and try to figure out the configuration using the hostfile (you can find plenty of tutorials by googling "mpirun hostfile")

Re: running serpent in parallel

Posted: Sun Oct 28, 2018 8:19 pm
by MojoJojo
My Linux distribution is fedora, version 28. I had a problem with executing the command, which is supposed to enable the OpenMP option as per the installation manual:

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CFLAGS += -DMPI
Which resulted in an error:

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bash: CFLAGS: command not found...
I solved this problem by simply removing the space left to the '+' and right to the '=':

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CFLAGS+=-DMPI
This solution is also applicable to the commands associated with setting up the GD library:

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LDFLAGS+=-ldg
instead of

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LDFLAGS += -ldg
and

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CFLAGS+=-DNO_GFX_MODE
instead of

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CFLAGS += -DNO_GFX_MODE