[petsc-dev] mpi_comm_create_group()

Adrian Croucher a.croucher at auckland.ac.nz
Thu Dec 2 18:53:32 CST 2021

On 12/3/21 12:09 PM, Jed Brown wrote:
> Many find MPI_Comm_split() to be a more convenient interface.
Yes, I don't think that will work for my case though, as my groups may 
overlap, and some processes may not be in any group.
> I think the man page is fairly clear.
> | MPI_Comm_create_group is similar to MPI_Comm_create; however, 
> MPI_Comm_create must be called by all processes in the group of comm, 
> whereas MPI_Comm_create_group must be called by all processes in 
> group, which is a subgroup of the group of comm.

Yes, it looks like the mpitutorial.com example I followed was a bit 
misleading then.


- Adrian

Dr Adrian Croucher
Senior Research Fellow
Department of Engineering Science
University of Auckland, New Zealand
email: a.croucher at auckland.ac.nz
tel: +64 (0)9 923 4611

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