Open MPI logo

Open MPI User's Mailing List Archives

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

Subject: Re: [OMPI users] memcpy overlap in ompi_ddt_copy_content_same_ddt and glibc 2.12
From: Jed Brown (jed_at_[hidden])
Date: 2010-11-11 06:46:56


On Thu, Nov 11, 2010 at 12:36, Number Cruncher <number.cruncher_at_[hidden]
> wrote:

> However as commented here:
> https://bugzilla.redhat.com/show_bug.cgi?id=638477#c86 the valgrind memcpy
> implementation is overlap-safe.
>

 Yes, of course. That's how the bug in Open MPI was originally detected.
 Of course you can't do production runs with valgrind.

Are you using an Intel Nehalem-class CPU?
>

No, Core 2 Duo and Opteron (but the Opterons still have older glibc).
 Reverse memcpy must only be turned on for Nehalem.

Jed