MPICH

MPICH is a high-performance and widely portable implementation of the Message Passing Interface (MPI) standard from the Argonne National Laboratory. This implementation provides all MPI functions and features required by the standard with comprehensive support for parallel computing applications. MPICH is widely adopted by multiple vendor partners including Intel, Hewlett Packard Enterprise (HPE), ParTec, Ohio State University (X-ScaleSolutions), and has been deployed on many Top 500 HPC systems. This README file should contain enough information to get you started with MPICH. More extensive installation and user guides can be found in the doc/installguide/install.pdf and doc/userguide/user.pdf files respectively in the release tarball, or the doc/wiki in the source code. The following instructions take you through a sequence of steps to get the default configuration (CH4 device with OFI network module, Hydra process management) of MPICH up and running. Note: For users of csh and tcsh shells, please refer to Using csh and tcsh Shells for shell-specific examples. The configure will try to determine the best device (the internal network modules) based on system environment. You may also supply a device configuration. E.g. If a failure occurs, the configure command will display the error. Most errors are straight-forward to follow. For example, if the configure command fails with: "No Fortran compiler found. If you don't need to build any Fortran programs, you can disable Fortran support using --disable-fortran. If you do want to build Fortran programs, you need to install a Fortran compiler such as gfortran or ifort before you can proceed." If you are unable to understand what went wrong, please go to Section (6) below, for reporting the issue to the MPICH developers and other users. This step should succeed if there were no problems with the preceding step. Check file m.txt. If there were problems, do a make clean and then run make again with V=1 to get the verbose output. This step collects all required executables and scripts in the bin subdirectory of the directory specified by the prefix argument to configure. Add the bin subdirectory of the installation directory to your path in your startup script (.bashrc for bash, etc.): These commands should display the path to your bin subdirectory of your install directory. MPICH uses a process manager for starting MPI applications. The process manager provides the "mpiexec" executable, together with other utility executables. MPICH comes packaged with multiple process managers; the default is called Hydra. If you have completed all of the above steps, you have successfully installed MPICH and run an MPI example. MPICH uses the CH4 device by default, which supports different network modules (netmods) for communication. This section covers the available CH4 netmods and their configuration options. Note: For information about alternate devices and channels (including legacy CH3), please refer to Alternate Channels and Devices. The ofi netmod provides support for the OFI network programming interface. To enable, configure with the following option: ... or the if lib/ and include/ are in the same directory, you can use the following option: If specifying the provider, the MPICH library will be optimized specifically for the requested provider by removing runtime branches to determine provider capabilities. Note that using this feature with a version of the libfabric library older than that recommended with this version of MPICH is unsupported and may result in unexpected behavior. This is also true when using the environment variable FI PROVIDER. Please refer to the MPICH documentation for the currently recommended version of libfabric. The ucx netmod provides support for the Unified Communication X library. It can be built with the following configure option: ... or the if lib/ and include/ are in the same directory, you can use the following option: By default, t