PetscSubcomm#
A decomposition of an MPI communicator into subcommunicators
Synopsis#
typedef struct _n_PetscSubcomm *PetscSubcomm;
Values#
PETSC_SUBCOMM_GENERAL- similar toMPI_Comm_split()each process sets the new communicator (color) they will belong to and the order within that communicatorPETSC_SUBCOMM_CONTIGUOUS- each new communicator contains a set of process with contiguous ranks in the original MPI communicatorPETSC_SUBCOMM_INTERLACED- each new communictor contains a set of processes equally far apart in rank from the others in that new communicator
Sample Usage#
PetscSubcommCreate()
PetscSubcommSetNumber()
PetscSubcommSetType(PETSC_SUBCOMM_INTERLACED);
ccomm = PetscSubcommChild()
PetscSubcommDestroy()
Example#
Consider a communicator with six processes split into 3 subcommunicators.
PETSC_SUBCOMM_CONTIGUOUS - the first communicator contains rank 0,1 the second rank 2,3 and the third rank 4,5 in the original ordering of the original communicator
PETSC_SUBCOMM_INTERLACED - the first communicator contains rank 0,3, the second 1,4 and the third 2,5
Note#
After a call to PetscSubcommSetType(), PetscSubcommSetTypeGeneral(), or PetscSubcommSetFromOptions() one may call
PetscSubcommChild() returns the associated subcommunicator on this process
PetscSubcommContiguousParent() returns a parent communitor but with all child of the same subcommunicator having contiguous rank
Developer Note#
This is used in objects such as PCREDUNDANT to manage the subcommunicators on which the redundant computations
are performed.
See Also#
PetscSubcommCreate(), PetscSubcommSetNumber(), PetscSubcommSetType(), PetscSubcommView(), PetscSubcommSetFromOptions()
Level#
advanced
Location#
Examples#
Index of all Sys routines
Table of Contents for all manual pages
Index of all manual pages