Other Preparations for Benchmarking

Window (IMB-EXT and IMB-RMA)

  1. An Info is set and MPI_Win_create is called, creating a window of size X for MY_COMM.
  2. For IMB-EXT, MPI_Win_fence is called to start an access epoch.

    Note

    IMB-RMA benchmarks do not require MPI_Win_fence since they use passive target communication mode.

File (IMB-IO)

To initialize the IMB-IO file, follow these steps:

  1. Select a file name. This parameter is located in the IMB_settings_io.h include file. In the case of a multi-<MPI command>, a suffix _g<groupid> is appended to the name. If the file name is per process, a second event suffix _<rank> is appended.

  2. Delete the file if it exists: open the file with MPI_MODE_DELETE_ON_CLOSE and close it. The file is deleted.

  3. Select a communicator to open the file: MPI_COMM_SELF for S_benchmarks and P_[ACTION]_priv.

  4. Select a mode: MPI_MODE_CREATE | MPI_MODE_RDWR

  5. Select an info routine as explained below.

Info

Intel® MPI Benchmarks uses an external function User_Set_Info which you implement for your local system. The default version is:

#include mpi.h
void User_Set_Info ( MPI_Info* opt_info)
#ifdef MPIIO
{/*  Set info for all MPI_File_open calls  */
*opt_info = MPI_INFO_NULL;
}
#endif
#ifdef EXT
{/*  Set info for all MPI_Win_create calls  */
*opt_info = MPI_INFO_NULL;
}
#endif

The Intel® MPI Benchmarks has no assumptions or restrictions on the implementation of this routine.

View (IMB-IO)

The file view is determined by the following settings: