# PCASMSetDMSubdomains
Indicates whether to use `DMCreateDomainDecomposition()` to define the subdomains, whenever possible. 
## Synopsis
```
#include "petscpc.h" 
PetscErrorCode PCASMSetDMSubdomains(PC pc, PetscBool flg)
```
Logically Collective


## Input Parameters

- ***pc  -*** the preconditioner
- ***flg -*** boolean indicating whether to use subdomains defined by the `DM`



## Options Database Key

- ***-pc_asm_dm_subdomains <bool> -*** use subdomains defined by the `DM`





## Note
`PCASMSetTotalSubdomains()` and `PCASMSetOverlap()` take precedence over `PCASMSetDMSubdomains()`,
so setting either of the first two effectively turns the latter off.


## See Also
 `PCASM`, `PCASMGetDMSubdomains()`, `PCASMSetTotalSubdomains()`, `PCASMSetOverlap()`
`PCASMCreateSubdomains2D()`, `PCASMSetLocalSubdomains()`, `PCASMGetLocalSubdomains()`

## Level
intermediate

## Location
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/ksp/pc/impls/asm/asm.c.html#PCASMSetDMSubdomains">src/ksp/pc/impls/asm/asm.c</A>


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


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