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Subject: Re: [OMPI users] Prototypes for Fortran MPI_ commands using 64-bit indexing
From: Jim Parker (jimparker96313_at_[hidden])
Date: 2013-10-30 19:00:56


Jeff,
  Here's what I know:
1. Checked FAQs. Done
2. Version 1.6.5
3. config.log file has been removed by the sysadmin...
4. ompi_info -a from head node is in attached as headnode.out
5. N/A
6. compute node info in attached as compute-x-yy.out
7. As discussed, local variables are being overwritten after calls to
MPI_RECV from Fortran code
8. ifconfig output from head node and computes listed as *-ifconfig.out

Cheers,
--Jim

On Wed, Oct 30, 2013 at 5:29 PM, Jeff Squyres (jsquyres) <jsquyres_at_[hidden]
> wrote:

> Can you send the information listed here:
>
> http://www.open-mpi.org/community/help/
>
>
> On Oct 30, 2013, at 6:22 PM, Jim Parker <jimparker96313_at_[hidden]> wrote:
>
> > Jeff and Ralph,
> > Ok, I downshifted to a helloWorld example (attached), bottom line
> after I hit the MPI_Recv call, my local variable (rank) gets borked.
> >
> > I have compiled with -m64 -fdefault-integer-8 and even have assigned
> kind=8 to the integers (which would be the preferred method in my case)
> >
> > Your help is appreciated.
> >
> > Cheers,
> > --Jim
> >
> >
> >
> > On Wed, Oct 30, 2013 at 4:49 PM, Jeff Squyres (jsquyres) <
> jsquyres_at_[hidden]> wrote:
> > On Oct 30, 2013, at 4:35 PM, Jim Parker <jimparker96313_at_[hidden]>
> wrote:
> >
> > > I have recently built a cluster that uses the 64-bit indexing
> feature of OpenMPI following the directions at
> > >
> http://wiki.chem.vu.nl/dirac/index.php/How_to_build_MPI_libraries_for_64-bit_integers
> >
> > That should be correct (i.e., passing -i8 in FFLAGS and FCFLAGS for OMPI
> 1.6.x).
> >
> > > My question is what are the new prototypes for the MPI calls ?
> > > specifically
> > > MPI_RECV
> > > MPI_Allgathterv
> >
> > They're the same as they've always been.
> >
> > The magic is that the -i8 flag tells the compiler "make all Fortran
> INTEGERs be 8 bytes, not (the default) 4." So Ralph's answer was correct
> in that all the MPI parameters are INTEGERs -- but you can tell the
> compiler that all INTEGERs are 8 bytes, not 4, and therefore get "large"
> integers.
> >
> > Note that this means that you need to compile your application with -i8,
> too. That will make *your* INTEGERs also be 8 bytes, and then you'll match
> what Open MPI is doing.
> >
> > > I'm curious because some off my local variables get killed (set to
> null) upon my first call to MPI_RECV. Typically, this is due (in Fortran)
> to someone not setting the 'status' variable to an appropriate array size.
> >
> > If you didn't compile your application with -i8, this could well be
> because your application is treating INTEGERs as 4 bytes, but OMPI is
> treating INTEGERs as 8 bytes. Nothing good can come from that.
> >
> > If you *did* compile your application with -i8 and you're seeing this
> kind of wonkyness, we should dig deeper and see what's going on.
> >
> > > My review of mpif.h and mpi.h seem to indicate that the functions are
> defined as C int types and therefore , I assume, the coercion during the
> compile makes the library support 64-bit indexing. ie. int -> long int
> >
> > FWIW: We actually define a type MPI_Fint; its actual type is determined
> by configure (int or long int, IIRC). When your Fortran code calls C, we
> use the MPI_Fint type for parameters, and so it will be either a 4 or 8
> byte integer type.
> >
> > --
> > Jeff Squyres
> > jsquyres_at_[hidden]
> > For corporate legal information go to:
> http://www.cisco.com/web/about/doing_business/legal/cri/
> >
> > _______________________________________________
> > users mailing list
> > users_at_[hidden]
> > http://www.open-mpi.org/mailman/listinfo.cgi/users
> >
> > <mpi-test-64bit.tar.bz2>_______________________________________________
> > users mailing list
> > users_at_[hidden]
> > http://www.open-mpi.org/mailman/listinfo.cgi/users
>
>
> --
> Jeff Squyres
> jsquyres_at_[hidden]
> For corporate legal information go to:
> http://www.cisco.com/web/about/doing_business/legal/cri/
>
> _______________________________________________
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