Re: [OMPI users] MPIIO and derived data types

2014-07-21 Thread Tom Rosmond
Rob, Well, if I understand what you are saying, maybe my concerns about sub-optimality are unfounded. Yes, the 'buffer' array is contiguous in memory for each subdomain, and that is what the successful call to 'mpi_file_read_at_all' sees. The call to 'mpi_type_indexed' creates my 'datatype' and

Re: [OMPI users] MPIIO and derived data types

2014-07-21 Thread Rob Latham
On 07/20/2014 04:23 PM, Tom Rosmond wrote: Hello, For several years I have successfully used MPIIO in a Fortran global atmospheric ensemble data assimilation system. However, I always wondered if I was fully exploiting the power of MPIIO, specifically by using derived data types to better

[OMPI users] MPIIO and derived data types

2014-07-20 Thread Tom Rosmond
Hello, For several years I have successfully used MPIIO in a Fortran global atmospheric ensemble data assimilation system. However, I always wondered if I was fully exploiting the power of MPIIO, specifically by using derived data types to better describe memory and file data layouts. All of my