PetscBuildTwoSidedType#
algorithm for setting up two-sided communication for use with PetscSF
Synopsis#
typedef enum {
PETSC_BUILDTWOSIDED_NOTSET = -1,
PETSC_BUILDTWOSIDED_ALLREDUCE = 0,
PETSC_BUILDTWOSIDED_IBARRIER = 1,
PETSC_BUILDTWOSIDED_REDSCATTER = 2
/* Updates here must be accompanied by updates in finclude/petscsys.h and the string array in mpits.c */
} PetscBuildTwoSidedType;
Values#
PETSC_BUILDTWOSIDED_ALLREDUCE- classical algorithm using anMPI_Allreduce()with a buffer of length equal to the communicator size. Not memory-scalable due to the large reduction size. Requires only an MPI-1 implementation.PETSC_BUILDTWOSIDED_IBARRIER- nonblocking algorithm based onMPI_Issend()andMPI_Ibarrier(). Proved communication-optimal in Hoefler, Siebert, and Lumsdaine (2010). Requires an MPI-3 implementation.PETSC_BUILDTWOSIDED_REDSCATTER- similar to above, but use more optimized function that only communicates the part of the reduction that is necessary. Requires an MPI-2 implementation.
See Also#
PetscCommBuildTwoSided(), PetscCommBuildTwoSidedSetType(), PetscCommBuildTwoSidedGetType()
Level#
developer
Location#
Index of all Sys routines
Table of Contents for all manual pages
Index of all manual pages