PETSC_COMM_WORLD

the equivalent of the MPI_COMM_WORLD communicator which represents all the processes that PETSc knows about.

Notes

By default PETSC_COMM_WORLD and MPI_COMM_WORLD are identical unless you wish to run PETSc on ONLY a subset of MPI_COMM_WORLD. In that case create your new (smaller) communicator, call it, say comm, and set PETSC_COMM_WORLD = comm BEFORE calling PetscInitialize(), but after MPI_Init() has been called.

The value of PETSC_COMM_WORLD should never be used or accessed before PetscInitialize() is called because it may not have a valid value yet.

See Also

PETSC_COMM_SELF

Level

beginner

Location

include/petscsys.h

Examples

src/dm/tutorials/ex10.c
src/dm/tutorials/ex22.c
src/dm/tutorials/ex21.c
src/dm/impls/stag/tutorials/ex4.c
src/ts/utils/dmplexlandau/tutorials/ex2.c
src/dm/tutorials/swarm_ex1.c
src/dm/label/tutorials/ex1.c
src/dm/impls/stag/tutorials/ex8.c
src/dm/tutorials/ex3.c
src/dm/tutorials/ex20.c

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