[Pkg-openmpi-maintainers] Bug#515116: libopenmpi-dev: Receive of cascaded derived datatypes disregards offset of inner custom type

[Markus Blatt]

Package: libopenmpi-dev
Version: 1.2.7~rc2-2
Severity: important

Hi,

In one of my applications I am using cascaded derived MPI datatypes
created with MPI_Type_struct. One of these types is used to just send
a part (one MPI_Char) of a struct consisting of an int followed by two
chars. I.e, the int at the beginning is/should be ignored.

This works fine if I use this data type on its own. 

Unfortunately I need to send another struct that contains an int and
the int-char-char struct from above. Again I construct a custom MPI
data type for this.

When sending this cascaded data type It seems that the offset of the
char in the inner custom type is disregarded on the receiving end and the
received data ('1') is stored in the first int instead of the
following char.

I have tested this code with both lam and mpich. There it worked as
expected (saving the '1' in the first char.

The last two lines of the output of the attached test case read

received global=10 attribute=0 (local=1 public=0)
received  attribute=1 (local=100 public=0)

for openmi instead off

received global=10 attribute=1 (local=100 public=0)
received  attribute=1 (local=100 public=0)

for lam and mpich.

The same problem is experienced when using version 1.3-2 of openmpi

Cheers,

Markus

-- System Information:
Debian Release: 5.0
  APT prefers testing
  APT policy: (700, 'testing'), (650, 'unstable'), (600, 'experimental')
Architecture: i386 (i686)

Kernel: Linux 2.6.28.4 (SMP w/2 CPU cores)
Locale: LANG=de_DE.UTF-8, LC_CTYPE=de_DE.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/bash

Versions of packages libopenmpi-dev depends on:
ii  libc6                        2.7-18      GNU C Library: Shared libraries
ii  libopenmpi1                  1.2.7~rc2-2 high performance message passing l
ii  openmpi-common               1.2.7~rc2-2 high performance message passing l

libopenmpi-dev recommends no packages.

libopenmpi-dev suggests no packages.

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