1. Call DMSetUp(packer) once you are done adding DMs. I will make it automatic in petsc-dev. 2. Call PetscSubcommDestroy() to free unused memory. 3. I suggest running your experiments with less than 64 procs. On Fri, Feb 3, 2012 at 18:32, <[email protected]>wrote:

Hi, I'm getting a segmentation violation error when I use DMCompositeGetISLocalToGlobalMappings on a DMComposite defined redundantly on subsets of the PETSC_COMM_WORLD. I could reproduce the error in the small code you can find here attached. It creates a PetsSubcomm from PETSC_COMM_WORLD, then it defines a DMDA on the Subcomm->comm and finally it packs it into a DMComposite. I get this error whenever I call DMCompositeGetISLocalToGlobalMapping on a DMComposite defined in such a way.

I would be glad if you could give it a look. Thank you Domenico