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Subject: Re: [OMPI users] Open MPI 1.2.4 verbosity w.r.t. osc pt2pt
From: Lisandro Dalcin (dalcinl_at_[hidden])
Date: 2007-12-11 09:08:01


On 12/10/07, Jeff Squyres <jsquyres_at_[hidden]> wrote:
> Brian / Lisandro --
> I don't think that I heard back from you on this issue. Would you
> have major heartburn if I remove all linking of our components against
> libmpi (etc.)?
>
> (for a nicely-formatted refresher of the issues, check out https://svn.open-mpi.org/trac/ompi/wiki/Linkers)

Sorry for the late response...

I've finally 'solved' this issue by using RTLD_GLOBAL for loading the
Python extension module that actually calls MPI_Init(). However, I'm
not completelly sure if my hackery is completelly portable.

Looking briefly at the end of the link to the wiki page, you say that
if the explicit linking to libmpi on componets is removed, then
dlopen() has to be explicitelly called.

Well, this would be a mayor headhace for me, because portability
issues. Please note that I've developed mpi4py on a rather old 32 bits
linux box, but it works in many different plataforms and OS's. I do
really do not have the time of testing and figure out how to
appropriatelly call dlopen() in platforms/OS's that I even do not have
access!!

Anyway, perhaps OpenMPI could provide an extension: a function call,
let say 'ompi_load_dso()' or something like that, that can be called
before MPI_Init() for setting-up the monster. What to you think about
this? Would it be hard for you?

-- 
Lisandro Dalcín
---------------
Centro Internacional de Métodos Computacionales en Ingeniería (CIMEC)
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