# PetscSplitOwnershipBlock
Given a global (or local) length determines a local (or global) length via a simple formula. Splits so each processors local size is divisible by the block size. 
## Synopsis
```
#include "petscsys.h" 
PetscErrorCode PetscSplitOwnershipBlock(MPI_Comm comm, PetscInt bs, PetscInt *n, PetscInt *N)
```
Collective (if N is `PETSC_DECIDE`)


## Input Parameters

- ***comm -*** MPI communicator that shares the object being divided
- ***bs -*** block size
- ***n -*** local length (or `PETSC_DECIDE` to have it set)
- ***N -*** global length (or `PETSC_DECIDE`)





## Notes
n and N cannot be both `PETSC_DECIDE`

If one processor calls this with N of `PETSC_DECIDE` then all processors
must, otherwise the program will hang.


## See Also
 `PetscSplitOwnership()`, `PetscSplitOwnershipEqual()`

## Level
developer

## Location
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/sys/utils/psplit.c.html#PetscSplitOwnershipBlock">src/sys/utils/psplit.c</A>


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[Edit on GitLab](https://gitlab.com/petsc/petsc/-/edit/release/src/sys/utils/psplit.c)


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