The definition of view on pg 205 and the illustration in figure 10.1
says that the filetype defines a pattern that is repeated to form the
view.
To me, the derived dataype (int,4) defines the pattern
(hole, int). Therefore, the file view will be
hole, int, hole, int, ...
I think this is fine; that was the intent all along.
But if the same datatype is used in MPI_Read, it means the buffer will
contain count "contiguous" copies of type datatype. Contiguous is
defined in terms of extent of the datatype (pg. 73, MPI-1), which for
the above is four. So, the memory layout will be
hole, int, int, int, ...
I think we need to define file tiling more precisely. The displacement
between consecutive filetypes is not the "extent" as in memory, but
"extent + lb(filetype)".
Rajeev