[petsc-dev] Sequential external packages and MPI

[Jed Brown]

"Smith, Barry F. via petsc-dev" <petsc-dev at mcs.anl.gov> writes:

>> Our Metis wrapper is marked as a sequential one, but since you are linking libmetis with MPI, this is problematic for some configurations.
>
>   What is your work flow? Are you using --prefix to compile particular combinations of external packages and put them in the prefix directory ? Then you can make PETSc builds and just use --with-xxx-dir=/prefixlocation to use them when building PETSc?
>
>   With this model you can use the sequential compilers for the sequential libraries and the MPI ones for the MPI libraries for example
>
>   ./configure --download-metis --with-mpi=0  --prefix=/home/bsmith/myprebuilts
>
>    ./configure --download-parmetis --with-metis-dir=/home/bsmith/myprebuilts --prefix=/home/bsmith/myprebuilts
>
>    For a sequential PETSc build that uses metis then
>
>   ./configure --with-metis-dir=/home/bsmith/myprebuilts ....--with-mpi=0
>
>   For a parallel PETSc build 
>
>  /configure --with-metis-dir=/home/bsmith/myprebuilts --with-parmetis-dir=/home/bsmith/myprebuilts.     

What if Pierre were to pull out the underlying compilers to configure
without mpicc wrappers, something like

  ./configure CC=gcc CXX=g++ --with-mpi-include=... --with-mpi-lib=...

Packages that don't framework.require MPI shouldn't be linked to MPI.