SupportMPI is a support class library with message passing interface (MPI) for KVS. By checking the flag KVS_SUPPORT_MPI in kvs.conf, MPI supported classes are compiled and available.
The following software packages are needed to compile SupportMPI.
MPI compiler, such as OpenMPI and MPICH, must be installed in your computing environment before compiling KVS.mpi.
For Linux, OpenMPI will be available by installing libopenmpi-dev. The following shows a command example with apt-get on Ubuntu Linux.
$ apt-get install openmpi-bin libopenmpi-dev
In case of Mac OS X environment, OpenMPI can be installed with HomeBrew as follows:
$ brew install openmpi
By default, mpicxx compiler is used for compiling the SupportMPI. If you want to change the MPI compiler, you can use the environmnet variable KVS_MPI_CPP to change it to your specified compiler as follows.
e.g.) Using Intel MPI compiler
$ export KVS_MPI_CPP=mpiicpc
Several example programs with the SupportMPI can be found in the Example/SupportMPI directory. Each of the programs can be easily compiled with kvsmake command. Note that the -use_mpi option need to be specified for the kvsmake to generate a Makefile with MPI comiple otions.
$ cd Example/SupportMPI
$ cd HelloWorld
$ kvsmake -G -use_mpi
$ kvsmake
The execution result of the "HelloWorld" program is shown as follows:
$ ./run.sh
Size = 4, Rank = 0
Size = 4, Rank = 1
Size = 4, Rank = 2
Size = 4, Rank = 3
If you use KVS compiled with the different compiler from the mpicxx wrapper compiler, you need to specify the compiler by using the environment variable OMPI_CXX for OpenMP or MPICH_CXX for MPICH as follows:
- OpenMP
e.g.)
$ OMPI_CXX=g++-6 kvsmake
- MPICH
e.g.)
$ MPICH_CXX=g++-6 kvsmake
The followings are setting examples for each HPC environment.
- K computer (RIKEN)
$ export KVS_MPI_CPP=mpiFCCpx
- Pi-computer (Kobe University)
$ export KVS_MPI_CPP=mpiFCCpx
- Pi-VizStudio (Kobe University)
$ export KVS_MPI_CPP=mpicxx