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From: Jeff Squyres \(jsquyres\) (jsquyres_at_[hidden])
Date: 2006-06-29 16:25:06


I think you may have caught us in an unintentional breakage. If your Open MPI was compiled as shared libraries and dynamic shared objects (the default), this error should not have happened since we did not change mpi.h. So there must be a second-order effect going on here (somehow the size of a back-end data structure caused a problem. Hrm.).

We'll look into this, because for where all of OMPI's functionality is in shared libraries and components, the user's application should be isolated from internal changes like this (i.e., and we can provide forward compatibility).

I suspect that something deeper is going on, so let us go investigate and come back with a more definitive statement.

> -----Original Message-----
> From: users-bounces_at_[hidden]
> [mailto:users-bounces_at_[hidden]] On Behalf Of Daniël Mantione
> Sent: Tuesday, June 27, 2006 11:09 AM
> To: Open MPI Users
> Subject: Re: [OMPI users] OpenMPI 1.1 backward compatible?
>
>
>
> On Tue, 27 Jun 2006, PeterKjellström wrote:
>
> > On Monday 26 June 2006 16:55, Daniël Mantione wrote:
> > > Hi!
> > >
> > > Just tried out OpenMPI 1.1. First impression is that it
> doesn't seem to
> > > be able to run OpenMPI 1.0.2 executables. The result of
> such an attempt
> > > can be seen below.
> > >
> > > Is it right that OpenMPI 1.1 cannot run 1.0.2 executables? If yes,
> > > shouldn't the major version of the library have been increased?
> >
> > If I'm not entierly mistaken OpenMPI (like LAM before it)
> requires you to
> > rebuild your applications when switching version. This goes
> for _ANY_ version
> > even minor ones.
>
> Well, no, the FAQ promises that applications will continue to work:
>
> > 10. We just upgraded our version of Open MPI; do I need to
> recompile all my MPI apps?
> >
> > It is unlikely. Most MPI applications solely interact with
> Open MPI through the standardized MPI
> > API and the constant values it publishes in mpi.h. The
> MPI-2 API will not change until the MPI
> > Forum changes it.
> >
> > We will try hard to make Open MPI's mpi.h stable such that
> the values will not change from
> > release-to-release. While we cannot guarantee that they
> will stay the same forever, we'll try hard
> > to make it so.
>
> So, it it a bug that things break? Or was it intentional?
>
> Daniël
>