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Subject: Re: [OMPI devel] IOF repair
From: Jeff Squyres (jsquyres_at_[hidden])
Date: 2008-07-10 11:29:23


Ya, no worries -- we're working on a fix. We're just debating exactly
*how* to fix it. See https://svn.open-mpi.org/trac/ompi/ticket/1135
if you want to keep up with the conversation.

On Jul 10, 2008, at 11:20 AM, Bogdan Costescu wrote:

> On Wed, 9 Jul 2008, Ralph Castain wrote:
>
>> stdin is read twice if rank=0 shares the node with mpirun
>
> I consider this to be a very serious regression. Many Fortran
> scientific programs (at least many that I know) read their input
> from stdin. This comes as a result of them being (or started to be)
> written many years ago with Fortran77 for which AFAIK there is no
> defined way of handling command line parameters, so reading from
> stdin is a convenient and portable way to put some data into the
> program as this is known to be open already and at a well known I/O
> unit.
>
> I just spent 2 days trying to understand why one such program
> (CHARMM) which worked fine for many MPI implementations on many
> platforms including the stable 1.2 series on this very cluster
> suddenly stops in some step related to processing input. After
> reading your message, everything makes sense...
>
>> Alternatively, we could ship 1.3 as-is, and warn users (similar to
>> 1.2) that
>> they should avoiding reading from stdin if there is any chance that
>> rank=0
>> could be co-located with mpirun. Note that most of our clusters do
>> not allow
>> such co-location - but it is permitted by default by OMPI.
>
> I don't know what setup your clusters have, but most that I have
> seen, including all those that I admin, do run mpirun/mpiexec and
> rank=0 on the same node. I really think that this will bite a lot of
> people.
>
> --
> Bogdan Costescu
>
> IWR, University of Heidelberg, INF 368, D-69120 Heidelberg, Germany
> Phone: +49 6221 54 8869/8240, Fax: +49 6221 54 8868/8850
> E-mail: bogdan.costescu_at_[hidden]
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-- 
Jeff Squyres
Cisco Systems