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Subject: Re: [OMPI users] Valgrind Warning
From: Jeff Squyres (jsquyres_at_[hidden])
Date: 2008-12-15 08:52:35


Hmm; it actually is on the list (you can see community/mirrors/
mirrors.txt).

But I think I made an error in the file when adding your host -- could
you try an update now?

On Dec 15, 2008, at 6:37 AM, Gabriele Fatigati wrote:

> Hi Jeff,
> i recompiled libmthca with --with-valgrind flag, and modified
> enviroment variables, but warnings doesnt' disappears..
>
> 2008/12/14 Jeff Squyres <jsquyres_at_[hidden]>:
>> On Dec 14, 2008, at 8:21 AM, Gabriele Fatigati wrote:
>>
>>> i have a strage problems with OpenMPI 1.2.5 Intel Compiled when i
>>> debug my code under Valgrind 3.3. In a very simple ping-pong MPI
>>> application, i retrieve strange warnings about MPI Communications,
>>> like MPI_Send,MPI_Recv. Valgrind tells me that there are
>>> uninitialized
>>> values in send/recv buffers, but there are initialized, i'm
>>> absolutely
>>> sure!
>>>
>>> There warnings are detected when my application runs over Infiniband
>>> net,
>>
>> This is because IB uses memory that does not come from the memory
>> allocator
>> that Valgrind is aware of (e.g., it may be memory that was
>> allocated by the
>> kernel itself). Hence, since Valgrind is unaware of the memory, it
>> thinks
>> that its contents are undefined. As such, it's quite likely that
>> you're
>> seeing false positives.
>>
>> The memchecker support in the upcoming v1.3 series made quite a few
>> advancements in the area of valgrind memory checking, and recent
>> versions of
>> libibverbs allow you to compile in valgrind extensions that tell
>> valgrind
>> "this memory is ok" (which prevents these false positives). I'm
>> pretty sure
>> that the OFED install does not enable these libibverbs valgrind
>> extensions;
>> you will likely need your own installation of libibverbs and your
>> verbs
>> plugin (libmthca for you, I think...?) that explicitly has the
>> valgrind
>> extensions enabled.
>>
>> --
>> Jeff Squyres
>> Cisco Systems
>>
>> _______________________________________________
>> users mailing list
>> users_at_[hidden]
>> http://www.open-mpi.org/mailman/listinfo.cgi/users
>>
>>
>
>
>
> --
> Ing. Gabriele Fatigati
>
> Parallel programmer
>
> CINECA Systems & Tecnologies Department
>
> Supercomputing Group
>
> Via Magnanelli 6/3, Casalecchio di Reno (BO) Italy
>
> www.cineca.it Tel: +39 051 6171722
>
> g.fatigati_at_[hidden]
> _______________________________________________
> users mailing list
> users_at_[hidden]
> http://www.open-mpi.org/mailman/listinfo.cgi/users

-- 
Jeff Squyres
Cisco Systems