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 type - value of type may be

    basic     -Use MPI persistent Isend/Irecv for communication (Default)
    window    -Use MPI-3 one-sided window for communication
    neighbor  -Use MPI-3 neighborhood collectives for communication

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

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