Re: tiling issues

Jean-Pierre Prost (jpprost@watson.ibm.com)
Wed, 16 Apr 1997 13:51:25 -0400

I would rather keep the tiling for files the same as for memory.
In other words, if the user really wants to achieve:
hole, int, hole, int, hole, int, ....
the filetype used should be:
(lb, 0), (int, 4)
which leads to an extent of 8.
I am not comfortable in defining yet another extent, just for filetypes.
There are already two extents, the original one defined by MPI-1, and the
true extent defined by MPI-2.
It is clear that the original extent (that of MPI-1) should be used for
filetypes.

Comments ?

Jean-Pierre

thakur @ mcs.anl.gov
04/16/97 01:10 PM

To: mpi-io @ mcs.anl.gov
cc: (bcc: Jean-Pierre Prost/Watson/IBM Research)
Subject: Re: tiling issues

> 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

Or the other option is to define tiling in the file as it is in
memory (using "contiguous"). Then (int,4) will not be sufficient to
define tiling. One would have to explicitly set the lb to 0. Then it
would work.

Rajeev