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# PetscSFSetFromOptions
set `PetscSF` options using the options database
## Synopsis
```
#include "petscsf.h"
PetscErrorCode PetscSFSetFromOptions(PetscSF sf)
```
Logically Collective
## Input Parameter
- ***sf -*** star forest
## Options Database Keys
- ***-sf_type -*** implementation type, see `PetscSFSetType()`
- ***-sf_rank_order -*** sort composite points for gathers and scatters in rank order, gathers are non-deterministic otherwise
- ***-sf_use_default_stream -*** Assume callers of `PetscSF` computed the input root/leafdata with the default CUDA stream. `PetscSF` will also
use the default stream to process data. Therefore, no stream synchronization is needed between `PetscSF` and its caller (default: true).
If true, this option only works with `-use_gpu_aware_mpi 1`.
- ***-sf_use_stream_aware_mpi -*** Assume the underlying MPI is CUDA-stream aware and `PetscSF` won't sync streams for send/recv buffers passed to MPI (default: false).
If true, this option only works with `-use_gpu_aware_mpi 1`.
- ***-sf_backend cuda | hip | kokkos -*** Select the device backend SF uses. Currently `PetscSF` has these backends: cuda, hip and Kokkos.
On CUDA (HIP) devices, one can choose cuda (hip) or kokkos with the default being kokkos. On other devices,
the only available is kokkos.
## See Also
`PetscSF`, `PetscSFCreate()`, `PetscSFSetType()`
## Level
intermediate
## Location
src/vec/is/sf/interface/sf.c
## Examples
src/vec/is/sf/tutorials/ex1.c
src/vec/is/sf/tutorials/ex1f.F90
src/vec/is/sf/tutorials/ex2.c
src/vec/is/sf/tutorials/ex3.c
## Implementations
PetscSFSetFromOptions_Window in src/vec/is/sf/impls/window/sfwindow.c
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[Edit on GitLab](https://gitlab.com/petsc/petsc/-/edit/release/src/vec/is/sf/interface/sf.c)
[Index of all PetscSF routines](index.md)
[Table of Contents for all manual pages](/manualpages/index.md)
[Index of all manual pages](/manualpages/singleindex.md)