PetscSFCreate

create a star forest communication context

Synopsis

#include "petscsf.h" 
PetscErrorCode PetscSFCreate(MPI_Comm comm, PetscSF *sf)

Collective

Input Parameter

• comm - communicator on which the star forest will operate

Output Parameter

• sf - new star forest context

Options Database Key

• -sf_type basic - Use MPI persistent Isend/Irecv for communication (Default)

• -sf_type window - Use MPI-3 one-sided window for communication

• -sf_type neighbor - Use MPI-3 neighborhood collectives for communication

• -sf_neighbor_persistent - If true, use MPI-4 persistent neighborhood collectives for communication (used along with -sf_type neighbor)

Note

When one knows the communication graph is one of the predefined graph, such as MPI_Alltoall(), MPI_Allgatherv(), MPI_Gatherv(), one can create a PetscSF and then set its graph with PetscSFSetGraphWithPattern(). These special SFs are optimized and they have better performance than the general SFs.

See Also

PetscSF, PetscSFSetType, PetscSFSetGraph(), PetscSFSetGraphWithPattern(), PetscSFDestroy()

Level

intermediate

Location

src/vec/is/sf/interface/sf.c

Examples

src/vec/is/sf/tutorials/ex3.c
src/vec/is/sf/tutorials/ex1f.F90
src/vec/is/sf/tutorials/ex1.c
src/vec/is/sf/tutorials/ex2.c

Implementations

PetscSFCreate_Allgather() in src/vec/is/sf/impls/basic/allgather/sfallgather.c
PetscSFCreate_Allgatherv() in src/vec/is/sf/impls/basic/allgatherv/sfallgatherv.c
PetscSFCreate_Alltoall() in src/vec/is/sf/impls/basic/alltoall/sfalltoall.c
PetscSFCreate_Gather() in src/vec/is/sf/impls/basic/gather/sfgather.c
PetscSFCreate_Gatherv() in src/vec/is/sf/impls/basic/gatherv/sfgatherv.c
PetscSFCreate_Neighbor() in src/vec/is/sf/impls/basic/neighbor/sfneighbor.c
PetscSFCreate_Basic() in src/vec/is/sf/impls/basic/sfbasic.c
PetscSFCreate_Window() in src/vec/is/sf/impls/window/sfwindow.c

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Index of all PetscSF routines
Table of Contents for all manual pages
Index of all manual pages