Intel® MPI Benchmarks User Guide and Methodology Description

# Synchronization

Before the actual benchmark measurement is performed, the constant `N_BARR` is used to regulate calls to:

`MPI_Barrier(MPI_COMM_WORLD)`

The`N_BARR` constant is defined in `IMB_settings.h` and `IMB_settings_io.h`, with the current value of 2.

See figure Control flow of IMB to ensure that all processes are synchronized.