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