# KSPSetUpOnBlocks
Sets up the preconditioner for each block in the block Jacobi, block Gauss-Seidel, and overlapping Schwarz methods. 
## Synopsis
```
#include "petscksp.h" 
#include "petscmat.h" 
PetscErrorCode KSPSetUpOnBlocks(KSP ksp)
```
Collective


## Input Parameter

- ***ksp -*** the `KSP` context



## Notes
`KSPSetUpOnBlocks()` is a routine that the user can optionally call for
more precise profiling (via -log_view) of the setup phase for these
block preconditioners.  If the user does not call `KSPSetUpOnBlocks()`,
it will automatically be called from within `KSPSolve()`.

Calling `KSPSetUpOnBlocks()` is the same as calling `PCSetUpOnBlocks()`
on the PC context within the `KSP` context.




## See Also
 [](chapter_ksp), `PCSetUpOnBlocks()`, `KSPSetUp()`, `PCSetUp()`, `KSP`

## Level
advanced

## Location
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/ksp/ksp/interface/itfunc.c.html#KSPSetUpOnBlocks">src/ksp/ksp/interface/itfunc.c</A>

## Examples
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/ksp/ksp/tutorials/ex10.c.html">src/ksp/ksp/tutorials/ex10.c.html</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/ksp/ksp/tutorials/ex27.c.html">src/ksp/ksp/tutorials/ex27.c.html</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/ksp/ksp/tutorials/ex72.c.html">src/ksp/ksp/tutorials/ex72.c.html</A><BR>


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[Edit on GitLab](https://gitlab.com/petsc/petsc/-/edit/release/src/ksp/ksp/interface/itfunc.c)


[Index of all KSP routines](index.md)  
[Table of Contents for all manual pages](/docs/manualpages/index.md)  
[Index of all manual pages](/docs/manualpages/singleindex.md)  
