[petsc-users] Load balancing problem with DMDA

[Barry Smith]

> On Oct 14, 2015, at 3:11 PM, Xiao, Jianjun (IKET) <jianjun.xiao at kit.edu> wrote:
> 
> Hello,
> 
> We have a finite volume code with structured grid. We use the DMDA data structure.
> 
> Now we have the load balancing problem as shown in the attached picture. The domain is decomposed into 4 partitions. The sub-domain in black (proc 2) is solid which is of no interest. We would like to calculate only the fluid part in proc 1, 3 and 4 which means the resource in proc 2 is wasted. Does DMDA now support multi-block with communication between blocks? I mean I build block 1 and assign to proc1, block 2 to proc 3 and block 3 to proc 4. So the solid sub-domain does not exist. Any suggestion?

No

> 
> Or I have to do it using DMPLEX? Since data structure of the whole code  is based on  DMDA, is there any "simple way" to switch from DMDA to DMPLEX without changing the loop structure in the code?

  No

  DMDA is for simple structured grids.

> 
> Thank you.
> 
> Best regards
> Jianjun
> <pic.JPG>