Other Preparations for Benchmarking#
Window (IMB-EXT and IMB-RMA)#
An
Infois set andMPI_Win_createis called, creating a window of sizeXforMY_COMM.For
IMB-EXT,MPI_Win_fenceis called to start an access epoch.Note
IMB-RMAbenchmarks do not requireMPI_Win_fencesince they use passive target communication mode.
File (IMB-IO)#
To initialize the IMB-IO file, follow these steps:
Select a file name. This parameter is located in the
IMB_settings_io.hinclude file. In the case of amulti-<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.Delete the file if it exists: open the file with
MPI_MODE_DELETE_ON_CLOSEand close it. The file is deleted.Select a communicator to open the file:
MPI_COMM_SELFforS_benchmarksandP_[ACTION]_priv.Select a mode:
MPI_MODE_CREATE | MPI_MODE_RDWRSelect an
inforoutine as explained below.
Info#
Intel(R) 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(R) 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:
disp = 0,datarep = nativeetype, filetypeasdefined in the IMB-IO Blocking Benchmarks sectioninfoas defined in the “Info” section above