petsc-3.15.0 2021-03-30
PetscSFReduceBegin
begin reduction of leafdata into rootdata, to be completed with call to PetscSFReduceEnd()
Synopsis
#include "petscsf.h"
PetscErrorCode PetscSFReduceBegin(PetscSF sf,MPI_Datatype unit,const void *leafdata,void *rootdata,MPI_Op op)
Collective
Input Arguments
| sf | - star forest
|
| unit | - data type
|
| leafdata | - values to reduce
|
| op | - reduction operation
|
Output Arguments
| rootdata | - result of reduction of values from all leaves of each root
|
Notes
When petsc is configured with device support, it will use its own mechanism to figure out whether the given data pointers
are host pointers or device pointers, which may incur a noticable cost. If you already knew the info, you should
use PetscSFReduceWithMemTypeBegin() instead.
See Also
PetscSFBcastBegin(), PetscSFReduceWithMemTypeBegin()
Level
intermediate
Location
src/vec/is/sf/interface/sf.c
Examples
src/vec/is/sf/tutorials/ex1.c.html
Index of all PetscSF routines
Table of Contents for all manual pages
Index of all manual pages