Intel® MPI Library Reference Manual for Linux* OS
The Intel® MPI Library also supports an optional region feature. The region is an IPM statistics format feature. See IPM Statistics Format for more details about IPM. This feature requires the source code modification. The MPI_Pcontrol function can be used.
Region is a named part of the source code marked by the start/end points through the standard MPI_Pcontrol function calls. The MPI_Pcontrol function isn’t used for the following special permanent regions:
Main region contains statistics information about all MPI calls from MPI_Init to MPI_Finalize. The main region gets the "*" name for IPM statistics output. The default output file for this region is stats.txt for native statistics format.
Complementary region contains statistics information not included into any named region. The region gets the "ipm_noregion" name in output for IPM statistics format. The default output file for this region is stats_noregion.txt for native statistics format.
If named regions are not used, the main regions and the complementary regions are identical and the complementary region is ignored.
Each region contains its own independent statistics information about MPI functions called inside the region.
The Intel® MPI Library supports the following types of regions:
Discontiguous (several open and close).
Intersected.
Covering a subset of MPI processes (part of the MPI_COMM_WORLD environment variable).
A region is opened by the MPI_Pcontrol(1, <name>) call and closed by the MPI_Pcontrol(-1, <name>) call where <name> is a zero terminated string with the region name. The <name> is used in output for IPM statistics format. The default output file for the region is stats_<name>.txt for native statistics format.
All open regions are closed automatically inside the MPI_Finalize environment variable.