Open MPI logo

Open MPI User's Mailing List Archives

  |   Home   |   Support   |   FAQ   |   all Open MPI User's mailing list

Subject: [OMPI users] memcpy overlap in ompi_ddt_copy_content_same_ddt and glibc 2.12
From: Number Cruncher (number.cruncher_at_[hidden])
Date: 2010-11-10 12:11:47


Just some observations from a concerned user with a temperamental Open
MPI program (1.4.3):

Fedora 14 (just released) includes glibc-2.12 which has optimized
versions of memcpy, including a copy backward.
http://sourceware.org/git/?p=glibc.git;a=commitdiff;h=6fb8cbcb58a29fff73eb2101b34caa19a7f88eba

I think the overlapping memcpy issue reported previously may be actively
triggered by this optimized memcpy and produce incorrect data.

Related posts:
http://www.open-mpi.org/community/lists/users/2009/04/9069.php
http://www.open-mpi.org/community/lists/users/2008/01/4918.php
http://www.open-mpi.org/community/lists/users/2007/08/3872.php

Original developer response:
http://www.open-mpi.org/community/lists/users/2007/08/3873.php

Current ticket:
https://svn.open-mpi.org/trac/ompi/ticket/1903