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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:
> 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.