[petsc-dev] ISLocalToGlobalMappingGetInfo

[Pierre Jolivet]

Again, with only 2 processes, where nproc is set to 2, I get the following numprocs and indices arrays on rank 0:
0	110 111 112 113 114 115 116 117 … 
1	110 111 112 113 114 115 116 117 …
Are these the expected values? If so, what is the true definition of nproc, please?

Thanks,
Pierre

> On 9 Aug 2019, at 3:45 AM, Smith, Barry F. <bsmith at mcs.anl.gov> wrote:
> 
> 
>  There could be a bug. Perhaps check the entries for that "extra" connection, are they all actual meaningful connections. The code that fills up these data structures is somewhat involved.
> 
>   Barry
> 
> 
>> On Aug 8, 2019, at 9:39 AM, Pierre Jolivet via petsc-dev <petsc-dev at mcs.anl.gov> wrote:
>> 
>> Hello,
>> When I use ISLocalToGlobalMappingGetInfo, e.g., in src/ksp/ksp/examples/tutorials/ex71.c ISLocalToGlobalMappingGetInfo(map, &nproc, &procs, &numprocs, &indices), I get the following value for nproc:
>> - with 1 process: 0
>> - with 2 processes: 2
>> In the source code, it says that nproc is the “number of processors that are connected to this one”.
>> How come this value is equal to the size of the global communicator when using 2 processes?
>> According to the comment in the source code, shouldn’t the returned value be 1?
>> 
>> Thanks,
>> Pierre
>