Re: [ESPResSo-users] mpirun runs python script in parallel

[Rudolf Weeber]

Hi Andreas,
On Thu, Feb 28, 2019 at 03:29:21PM +0100, Andreas Härtel wrote:
> Dear ESPResSo list,
> 
> ESPResSo has been running fine for me: calling
>  mpirun -n 4 pypresso <script>
> always resulted in running the python script on a single core and only
> internally running ESPResSo in parallel.
> 
> Then I updated anaconda2 using
>  conda install mpi4py
> and afterwards the above command was running my python script in parallel: I
> removed the mpi4pi module using conda uninstall, but the problem remained.
> Even after remaking and rebuilding ESPResSo.
> 
> I cannot see where something is going wrong:
> does anyone has an idea?
Did you use the same script?

Generally speaking, mpirun pypresso script.py
runs script.py multiple times. The coupling only happens at the time you 
instance the System class
via
s=espressomd.System(...)
So, as a first step you might try to move that call to the top of your script.

Regards, Rudolf