Open MPI logo

Open MPI User's Mailing List Archives

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

Subject: Re: [OMPI users] Valgrind Warning
From: Tim Mattox (timattox_at_[hidden])
Date: 2008-12-15 10:44:59


Gabriele,
You should switch the the upcoming v1.3 release as soon as you can,
via either the v1.3rc2 tarball or one of the v1.3rc3 nightly tarballs,
available here: http://www.open-mpi.org/nightly/
We are very close to v1.3, so not much should be different between
those versions and the final v1.3.

To see why you should switch, read the FAQ entries about Memchecker
that start here:
http://www.open-mpi.org/faq/?category=debugging#memchecker_what

On Mon, Dec 15, 2008 at 9:34 AM, Gabriele Fatigati <g.fatigati_at_[hidden]> wrote:
> PS: i'm using openmpi 1.2.5..
>
> 2008/12/15 Gabriele Fatigati <g.fatigati_at_[hidden]>:
>> Hi Jeff,
>> i recompiled libibverbs and libmthca with valgrind flas, but for
>> strage reasons, only warning over MPI_Send are disappears, but
>> warnings over MPI_Recv remains!
>>
>> 2008/12/15 Jeff Squyres <jsquyres_at_[hidden]>:
>>> Whoops; that was a reply to the wrong message. :-)
>>>
>>> You'll need to recompile both libiverbs and libmthca with the valgrind flag,
>>> and use the enhanced memchecker support in v1.3.
>>>
>>> I have not personally verified that all the warnings disappear in this
>>> configuration (I was hoping to verify this somewhere during the v1.3
>>> series).
>>>
>>>
>>>
>>>>
>>>> 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
>>>>
>>>> _______________________________________________
>>>> users mailing list
>>>> users_at_[hidden]
>>>> http://www.open-mpi.org/mailman/listinfo.cgi/users
>>>
>>>
>>> --
>>> 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]
>>
>
>
>
> --
> 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
>

-- 
Tim Mattox, Ph.D. - http://homepage.mac.com/tmattox/
 tmattox_at_[hidden] || timattox_at_[hidden]
    I'm a bright... http://www.the-brights.net/