User`s guide

Intel® MPI Library User’s Guide for Linux* OS

2.9.2. Running an MPI Application

To run an MPI application on the host node and the Intel® Xeon Phi™ coprocessor, do

the following:

1. Ensure that NFS is properly set up between the hosts and the Intel® Xeon Phi™

coprocessor(s). For information on how to set up NFS on the Intel® Xeon Phi™

coprocessor(s), visit the Intel® Xeon Phi™ coprocessor developer community at

http://software.intel.com/en-us/mic-developer.

2. Use the I_MPI_MIC_POSTFIX environment variable to append the .mic postfix

extension when running on the Intel® Xeon Phi™ coprocessor.

$ export I_MPI_MIC_POSTFIX=.mic

3. Make sure your ~/mpi_hosts file contains the machine names of your Intel® Xeon®

host processors and the Intel® Xeon Phi™ coprocessor(s). For example:

$ cat ~/mpi_hosts

clusternode1

clusternode1-mic0

4. Launch the executable file from the host.

$ export I_MPI_MIC=on

$ mpirun -n 4 -hostfile ~/mpd.hosts ./myprog

NOTE: You can also use the -configfile and -machinefile options.

To run the application on Intel® Xeon Phi™ coprocessor only, follow the steps described

above and ensure that mpd.hosts contains only the Intel® Xeon Phi™ coprocessor name.