Open MPI logo

Open MPI User's Mailing List Archives

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

Subject: Re: [OMPI users] MPI_AllGather null terminator character
From: Jeff Squyres (jsquyres_at_[hidden])
Date: 2012-01-31 07:52:30

On Jan 31, 2012, at 3:59 AM, Gabriele Fatigati wrote:

> I have very interesting news. I recompiled OpenMPI 1.4.4 enabling the memchecker.
> Now the warning on strcmp is disappeared also without buffers initializations using memset!
> So the warning is a false positive? My simple code is safe?

If you were using IB as the network transport, yes, it's a false positive.

With memchecker enabled, Open MPI will *always* tell Valgrind that the entire contents of the buffer are defined, even when the data is coming from an OS-bypass transport (such as an OpenFabrics-based device, like IB).

Jeff Squyres
For corporate legal information go to: