use of mpi derived data types in nfmpi_iput_vara

[Rob Latham]

On Tue, Feb 12, 2013 at 08:49:20AM -0700, Jim Edwards wrote:
> Are there any limitations to the data type passed to nfmpi_iput_vara?   I
> am trying to create a
> type using mpi_type_create_subarray and pass it to nfmpi_iput_vara and I am
> getting an error
> with traceback:
> 
> #10 0x00002b06f5f90ce3 in PMPI_Pack () from
> /opt/ibmhpc/pe1209/mpich2/gnu/lib64/libmpich.so.3
> #11 0x00000000005c9d2f in ncmpii_data_repack ()
> #12 0x00000000005b4532 in ncmpii_igetput_varm ()
> #13 0x00000000005969ed in ncmpi_iput_vara ()
> 
> 
> Is this a possible bug in parallel-netcdf or are my assumptions about usage
> incorrect?

Wow, an error from MPI_Pack... and one that causes a traceback.   

and it's IBM's MPI_Pack, sort of, by way of MPICH.

So, you've caused some surprise here. 

Can you share the type with us?  Or, if it's hard to capture (because
it's generated algorithmically) you might, depending on how IBM built
their MPI, have access to the c routine MPIDU_Datatype_debug:

 MPIDU_Datatype_debug(MPI_Datatype type, int array_ct)

(128 should be big enough for array_ct)

and that should spit out a bunch of information about the datatype:
enough that I could re-create it and see if other MPI implementations
choke when packing it.

==rob

-- 
Rob Latham
Mathematics and Computer Science Division
Argonne National Lab, IL USA