# PCBJKOKKOS
Defines a preconditioner that applies a Krylov solver and preconditioner to the blocks in a `MATSEQAIJ` matrix on the GPU using Kokkos 
## Options Database Key

- ***-pc_bjkokkos_ -*** options prefix for its `KSP` options





## Note
For use with -ksp_type preonly to bypass any computation on the CPU


## Developer Notes
The documentation is incomplete. Is this a block Jacobi preconditioner?

Why does it have its own `KSP`? Where is the `KSP` run if used with -ksp_type preonly?


## See Also
 `PCCreate()`, `PCSetType()`, `PCType`, `PC`, `PCBJACOBI`,
`PCSHELL`, `PCCOMPOSITE`, `PCSetUseAmat()`, `PCBJKOKKOSGetKSP()`

## Level
intermediate

## Location
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/ksp/pc/impls/bjacobi/bjkokkosbjkokkos.kokkos.cxx.html#PCBJKOKKOS">src/ksp/pc/impls/bjacobi/bjkokkosbjkokkos.kokkos.cxx</A>


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[Edit on GitLab](https://gitlab.com/petsc/petsc/-/edit/release/src/ksp/pc/impls/bjacobi/bjkokkosbjkokkos.kokkos.cxx)


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