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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
jsquyres_at_[hidden]
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