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Subject: Re: [OMPI users] OpenMPI Run-Time "Freedom" Question
From: Michael E. Thomadakis (miket7777_at_[hidden])
Date: 2010-08-13 12:58:20


  On 08/12/10 21:53, Jed Brown wrote:
>
> Or OMPI_CC=icc-xx.y mpicc ...
>

If we enable a different set of run time library paths for Intel
compilers than those used to build OMPI when we compile and execute the
MPI app these new run-time libs will be accessible to OMPI libs to run
against instead of those used when OMPI was being built right? I would
think that this may cause some problems if for some reason something in
the modern run-time libfs differs from the ones used when OMPI was built ?

A user is hoping to avoid rebuilding his OMPI app but i guess just
change LD_LIBRARY_PATH to the latest Intel compile run-time libs and
just launch it with teh latest and greatest Intel Libs.... I mentioned
to him that the right way is to build the combination of OMPI + Intel
run-time that the application is known to work with (since some may
fail) but he wants me to insert a fixed run-time lib path for OMPI libs
but use different and variable one for the run-time libs of the OMPI
application! It is frustrating with people who get "great ideas" but
then they presss someone else to make them work instead of doing this
themselves....

anyway thanks....

Michael
>
> Jed
>
>> On Aug 12, 2010 5:18 PM, "Ralph Castain" <rhc_at_[hidden]
>> <mailto:rhc_at_[hidden]>> wrote:
>>
>>
>> On Aug 12, 2010, at 7:04 PM, Michael E. Thomadakis wrote:
>>
>> > On 08/12/10 18:59, Tim Prince wrote:
>> >>...
>>
>> The "easy" way to accomplish this would be to:
>>
>> (a) build OMPI with whatever compiler you decide to use as a "baseline"
>>
>> (b) do -not- use the wrapper compiler to build the application.
>> Instead, do "mpicc --showme" (or whatever language equivalent you
>> want) to get the compile line, substitute your "new" compiler library
>> for the "old" one, and then execute the resulting command manually.
>>
>> If you then set your LD_LIBRARY_PATH to the "new" libs, it might work
>> - but no guarantees. Still, you could try it - and if it worked, you
>> could always just explain that this is a case-by-case situation, and
>> so it -could- break with other compiler combinations.
>>
>> Critical note: the app developers would have to validate the code
>> with every combination! Otherwise, correct execution will be a
>> complete crap-shoot - just because the app doesn't abnormally
>> terminate does -not- mean it generated a correct result!
>>
>>
>>
>>
>> > Thanks for the information on this. We indeed use Intel Compiler
>> set 11.1.XXX + OMPI 1.4.1 and ...
>>
>>
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>
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