Re: [ESPResSo] MPI issue

[Kai Grass]

Hi Tristan,

thanks again for the config-log. The solution you found (renaming the  
folder) is in fact solving your problem, but as you might have  
guessed it is not the optimal way ;)

Am 03.10.2007 um 18:03 schrieb Tristan Bereau:

> Compiler settings:
> ------------------
> MPI                     = mpich
> compiler                = mpicc
> linker                  = mpicc
> c compiler flags        = -finline-limit=1000000 -fomit-frame-pointer
> -funroll-loops -floop-optimize -ffast-math -Wall -Wno-unused-function
> -O3 -malign-double -msse2 -mfpmath=sse -march=nocona
> c preprocessor flags    =  -I/opt/mpich/include
> linker flags            =  -L/opt/mpich/ch-p4/lib
> libraries               = -lfftw3  -ltcl8.4  -lmpich -lm
> using debug flags       = no
> using profiling flags   = no
> inline                  =
>
>
> I think the problem comes from the 'MPI = mpich' line.  Even if  
> mpicc is
> set in the environment by OpenMPI (I checked using a 'which' command),
> ESPResSo links to 'mpich' in the directory /opt/mpich.

This is the "problem". Configure finds a working mpich library on  
your system and chooses that one as default option. (After renaming,  
it doesn't find it anymore ... so everything is fine now)

> I just discovered right now that mpich and openMPI are two different
> programs, so I'm guessing I had mpich by default on my computer and  
> it's
> just not compatible with ESPResSo...

Yes, they are. And especially the mpirun of OpenMPI doesn't work with  
the mpich-library.

OpenMPI is supported by the "generic mpi" interface, but in  
configure, mpich has precedence over generic. You can force the  
generic interace to be used by using the configure flag with-mpi, i.e.:

./configure --with-mpi=generic

This disables the "guessing" for the correct mpi libraries and should  
resolve your problem without renaming the folder.

Enjoy using Espresso,

Kai