[mpich-discuss] Bug in MPI_WIN_SHARED_QUERY using MPICH-3.0.4 from Fortran95-code

[Junchao Zhang]

Michael,
  I installed mpich-3.0.4 and could reproduce the bug you reported. I also
found it happened in C code. So the bug was not related to F90 bindings.
  Fortunately, I think the bug was fixed. With MPICH-3.1.3, with either C
or Fortran code, the problem disappears.
  Thanks.


--Junchao Zhang

On Mon, Dec 15, 2014 at 9:56 AM, Rajeev Thakur <thakur at mcs.anl.gov> wrote:
>
> I don't see the problem with the latest version of MPICH on my laptop.
> This is what I get:
>
>  ---Info-print just BEFORE calling MPI_WIN_QUERY:  idisplace_unit=
>  -6666
>  ===Info-print just AFTER calling MPI_WIN_QUERY:   idisplace_unit=
>    1
>
> Rajeev
>
>
> On Dec 15, 2014, at 4:21 AM, Michael.Rachner at dlr.de wrote:
>
> > Dear Junchao,
> >
> > I attached a downsized  Fortran95 program for testing the MPI-3 shared
> memory feature (MPI_WIN_ALLOCATE_SHARED, MPI_WIN_SHARED_QUERY).
> > You may add it to your MPICH test suite.
> > (The program is not secret, so I place it here for everybody, because it
> may serve also as an example, how to do the shared memory coding in a
> Ftn-code.)
> >
> > In that program I have inserted 2 ad-hoc prints, just before and just
> after the call of sbr MPI_WIN_SHARED_QUERY,
> > which print the value of  the 4th-parameter DISP_UNIT (named
>  idisplace_unit   in the code)  of that sbr .
> >
> > You can run the program by:
> >    mpif90 sharedmemtest.f90
> >    mpiexec -np 2 -bind-to core -prepend-rank ./a.out
> >
> > On our LINUX cluster with MPICH-3.0.4 and Intel-14.0.1  the 2
> print-stmts write this:
> >
> > [0]  ---Info-print just BEFORE calling MPI_WIN_QUERY:  idisplace_unit=
>      -6666         ß  -6666 is my arbitrary initialization value
> > [0]  ===Info-print just AFTER calling MPI_WIN_QUERY:   idisplace_unit=
>      -6666
> > [1]  ---Info-print just BEFORE calling MPI_WIN_QUERY:  idisplace_unit=
>      -6666
> > [1]  ===Info-print just AFTER calling MPI_WIN_QUERY:   idisplace_unit=
>      -6666
> >
> > You see, that sbr MPI_WIN_SHARED_QUERY does not overwrite the
> initialized value, but should do it.
> > I observed the same wrong behavior also in our Fortran95-CFD-code.
> >
> > I cannot easily install another MPICH-version. We have only MPICH-3.0.4
> . So, do you find that behavior with that program also with the most recent
> MPICH-version?
> >
> > Greetings
> > Michael Rachner
> >
> >
> >
> > Von: Junchao Zhang [mailto:jczhang at mcs.anl.gov]
> > Gesendet: Freitag, 12. Dezember 2014 20:50
> > An: <discuss at mpich.org>
> > Betreff: Re: [mpich-discuss] Bug in MPI_WIN_SHARED_QUERY using
> MPICH-3.0.4 from Fortran95-code
> >
> > Michael,
> >  I could not reproduce the problem with MPICH master. I checked MPICH's
> F90 binding of this routine. It looks good. There are C tests for this
> routine in MPICH test suite. They also ran fine.
> >  Could you either upgrade your MPI to MPICH-3.1.3 or send me your test
> case?
> >  Thanks.
> >
> > --Junchao Zhang
> >
> > On Fri, Dec 12, 2014 at 4:53 AM, <Michael.Rachner at dlr.de> wrote:
> > Dear developers of MPICH,
> >
> > I am running MPICH-3.0.4 with a Fortran95-code on a LINUX-cluster using
> the INTEL-14.0.1 Ftn-compiler.
> > In that code I employ the shared memory feature (using
> MPI_WIN_ALLOCATE_SHARED and MPI_WIN_SHARED_QUERY).
> > It works fine, but nevertheless I detected a little bug in
> MPI_WIN_SHARED_QUERY:
> >
> >      MPI_WIN_SHARED_QUERY(WIN, RANK, SIZE, DISP_UNIT, BASEPTR, IERROR)
> >
> > The MPI-3.0 Standard document (chapter 11.2, on p. 410)  prescribes that
> the 4th parameter  DISP_UNIT  is a result from the call of this sbr.
> > However, with MPICH no value is returned for DISP_UNIT.
> >
> > You can easily test that, by setting  DISP_UNIT  to a control number (
> e.g.  DISP_UNIT = -7777 )   just before the call of sbr
> MPI_WIN_SHARED_QUERY.
> > Just after that sbr-call   the variable  DISP_UNIT  still contains that
> control number, but should not.
> >
> > Greetings
> > Michael Rachner
> >
> >
> >
> >
> > _______________________________________________
> > discuss mailing list     discuss at mpich.org
> > To manage subscription options or unsubscribe:
> > https://lists.mpich.org/mailman/listinfo/discuss
> > <sharedmemtest.f90>_______________________________________________
> > discuss mailing list     discuss at mpich.org
> > To manage subscription options or unsubscribe:
> > https://lists.mpich.org/mailman/listinfo/discuss
>
> _______________________________________________
> discuss mailing list     discuss at mpich.org
> To manage subscription options or unsubscribe:
> https://lists.mpich.org/mailman/listinfo/discuss
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.mpich.org/pipermail/discuss/attachments/20141215/afecf419/attachment.html>
-------------- next part --------------
_______________________________________________
discuss mailing list     discuss at mpich.org
To manage subscription options or unsubscribe:
https://lists.mpich.org/mailman/listinfo/discuss