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;
PETSC_BUILDTWOSIDED_ALLREDUCE - classical algorithm using an MPI_Allreduce with
a buffer of length equal to the communicator size. Not memory-scalable due to
the large reduction size. Requires only MPI-1.
PETSC_BUILDTWOSIDED_IBARRIER - nonblocking algorithm based on MPI_Issend and MPI_Ibarrier.
Proved communication-optimal in Hoefler, Siebert, and Lumsdaine (2010). Requires MPI-3.
PETSC_BUILDTWOSIDED_REDSCATTER - similar to above, but use more optimized function
that only communicates the part of the reduction that is necessary. Requires MPI-2.
Level:developer
Location:include/petscsys.h
Index of all Sys routines
Table of Contents for all manual pages
Index of all manual pages