[MPIWG Fortran] [mpiwg-tools] Proposal: MPI_SIZEOF not profiled

Rolf Rabenseifner rabenseifner at hlrs.de
Wed May 21 02:11:17 CDT 2014


Yes, to take the time is a good idea, but best would be to 
take the time now and having the final text latest at the end
of this meeting. To make a 3 month pause would not help.

And for me, the result goes in this direction:
> >Allow for all these special cases that they are non-interceptable,
> >and require that the PMPI version is still available,
> >and to mention "macro in C" only as an "e.g.",
> >and the list includes the existing list plus MPI_SIZEOF
> >plus status conversion routines.
> >Due to the problems in the existing wording, and with MPI_SIZEOF,
> >I would propose it as an erratum, that is needed for MPI-3.1.

Best regards
Rolf 

----- Original Message -----
> From: "Martin Schulz" <schulzm at llnl.gov>
> To: mpiwg-tools at lists.mpi-forum.org
> Cc: "MPI-WG Fortran working group" <mpiwg-fortran at lists.mpi-forum.org>
> Sent: Tuesday, May 20, 2014 1:40:26 AM
> Subject: Re: [mpiwg-tools] [MPIWG Fortran] Proposal: MPI_SIZEOF not profiled
> 
> Hi Rolf,
> 
> I agree and (I think) so does Jeff - I think Jeff’s point was only
> that we
> should take the time and get the wording right. We can still bring
> this up
> as an errata item in Japan and it will get into MPI 3.1.
> 
> Sound OK?
> 
> Martin
> 
> ________________________________________________________________________
> Martin Schulz, schulzm at llnl.gov, http://scalability.llnl.gov/
> CASC @ Lawrence Livermore National Laboratory, Livermore, USA
> 
> 
> 
> 
> 
> 
> 
> 
> On 5/19/14, 1:49 PM, "Rolf Rabenseifner" <rabenseifner at hlrs.de>
> wrote:
> 
> >I'll be not at the June Meeting in Chicago. My apologies.
> >
> >For me, the solution is now nearly clear:
> >Allow for all these special cases that they are non-interceptable,
> >and require that the PMPI Version is still available,
> >and to mention "macro in C" only as an "e.g.",
> >and the list includes the existing list plus MPI_SIZEOF
> >plus status conversion routines.
> >Du to the problems in the existing wording, and with MPI_SIZEOF,
> >I would propose it as an erratum, that is needed for MPI-3.1.
> >
> >Best regards
> >Rolf
> >
> >----- Original Message -----
> >> From: "Jeff Squyres (jsquyres)" <jsquyres at cisco.com>
> >> To: "MPI-WG Fortran working group"
> >> <mpiwg-fortran at lists.mpi-forum.org>
> >> Cc: mpiwg-tools at lists.mpi-forum.org
> >> Sent: Monday, May 19, 2014 8:19:58 PM
> >> Subject: Re: [mpiwg-tools] [MPIWG Fortran] Proposal: MPI_SIZEOF
> >> not
> >>profiled
> >> 
> >> Ok.  Will any other Fortran people be there?  (besides me)
> >> 
> >> 
> >> On May 19, 2014, at 2:03 PM, Martin Schulz <schulzm at llnl.gov>
> >> wrote:
> >> 
> >> > Yes, sounds like it - I¹ll take 428 off the list then. We should
> >> > take some
> >> > time on Monday afternoon as part of the tools WG time to talk
> >> > about
> >> > this.
> >> > 
> >> > Martin
> >> > 
> >> > 
> >>________________________________________________________________________
> >> > Martin Schulz, schulzm at llnl.gov, http://scalability.llnl.gov/
> >> > CASC @ Lawrence Livermore National Laboratory, Livermore, USA
> >> > 
> >> > 
> >> > 
> >> > 
> >> > 
> >> > 
> >> > 
> >> > 
> >> > On 5/19/14, 8:35 AM, "Jeff Squyres (jsquyres)"
> >> > <jsquyres at cisco.com>
> >> > wrote:
> >> > 
> >> >> I think we need to push this errata out to the Japan meeting.
> >> >>  There
> >> >> seems to be a bunch of subtlety here; trying to rush this
> >> >> through
> >> >> today
> >> >> does not seem like a good idea just to meet the T-2 week
> >> >> deadline
> >> >> for the
> >> >> Chicago meeting (which technically expires at 2pm US Central
> >> >> time
> >> >> today
> >> >> -- which is about 3.5 hours from now).
> >> >> 
> >> >> Let me try to summarize the salient points so far:
> >> >> 
> >> >> 1. The old text kinda sucks:
> >> >>  a. it says "macros" (including the section title) where it
> >> >>  really
> >> >> means "not interceptable"
> >> >>  b. p19 implies that these function can only be macros in C
> >> >>  (not
> >> >> inlined, and not in Fortran), which seems to contradict p555
> >> >> 
> >> >> 2. We need to add the Status conversion functions in there
> >> >> 
> >> >> 3. We want to add MPI_SIZEOF (which is Fortran-only, BTW) to
> >> >> the
> >> >> list
> >> >> 
> >> >> 4. The use of the word "inline" seems to be a bad idea because
> >> >> it
> >> >> can
> >> >> have many different meanings.  We should say that these
> >> >> functions
> >> >> are not
> >> >> interceptable, which is the real requirement.
> >> >> 
> >> >> 5. I think it would be better to change p555 to not say
> >> >> "macros"
> >> >> (i.e.,
> >> >> "non-interceptable"), but rather to say "the routines listed in
> >> >> 2.6.4"
> >> >> (i.e., who cares what the reason is -- just cite 2.6.4 and let
> >> >> 2.6.4
> >> >> explain everything).
> >> >> 
> >> >> Is that all?
> >> >> 
> >> >> 
> >> >> 
> >> >> 
> >> >> On May 19, 2014, at 11:08 AM, Rolf Rabenseifner
> >> >> <rabenseifner at hlrs.de>
> >> >> wrote:
> >> >> 
> >> >>> Yes, the "allowed as macros" on MPI-3.0 p555:32
> >> >>> would allow a different mechanism for these routines
> >> >>> that makes them non-interceptable.
> >> >>> 
> >> >>> If this "non-interceptable" is done by other means
> >> >>> than macro, then p555:35 "For routines implemented
> >> >>> as macros, it is still required that the PMPI_
> >> >>> version be supplied" would not apply!
> >> >>> 
> >> >>> It is bad to use different wording for having
> >> >>> better English quality ;-(
> >> >>> 
> >> >>> And your are right, my "#ifdef MPI_Wait" says
> >> >>> therefore nothing.
> >> >>> 
> >> >>> Do you all agree that wording in
> >> >>> p19:48 - p20:5 and p555:31-37 is at all inconsistent
> >> >>> and therefore new and useful wording is needed
> >> >>> in this erratum?
> >> >>> 
> >> >>> Rolf
> >> >>> 
> >> >>> ----- Original Message -----
> >> >>>> From: "N.M. Maclaren" <nmm1 at cam.ac.uk>
> >> >>>> To: "MPI-WG Fortran working group"
> >> >>>> <mpiwg-fortran at lists.mpi-forum.org>
> >> >>>> Sent: Monday, May 19, 2014 4:35:10 PM
> >> >>>> Subject: Re: [MPIWG Fortran] [mpiwg-tools] Proposal:
> >> >>>> MPI_SIZEOF
> >> >>>> not
> >> >>>> profiled
> >> >>>> 
> >> >>>> On May 19 2014, Rolf Rabenseifner wrote:
> >> >>>>> 
> >> >>>>> Bill,
> >> >>>>> 
> >> >>>>> your text goes beyond the errata goal.
> >> >>>>> 
> >> >>>>> The errata goal was:
> >> >>>>> - adding the missing Status conversion
> >> >>>>> - adding MPI_SIZEOF
> >> >>>>> 
> >> >>>>> And this works as errata.
> >> >>>>> 
> >> >>>>> Your goal is to allow also
> >> >>>>> - Fortran non-interceptable for these routines.
> >> >>>>> 
> >> >>>>> Your additional Change is to allow other methods
> >> >>>>> than C macros for C.
> >> >>>>> This would prevent "#ifdef MPI_Wtime".
> >> >>>>> 
> >> >>>>> All this would be MPI-4.0 and not MPI-3.0 errata.
> >> >>>> 
> >> >>>> Would it?  I don't know what useful effect you would expect
> >> >>>> "#ifdef MPI_Wtime" to achieve, but it assuredly would NOT
> >> >>>> tell
> >> >>>> you (reliably) whether or not it can be accessed through the
> >> >>>> profiling interface.  14.2 says:
> >> >>>> 
> >> >>>>   1. provide a mechanism through which all of the MPI defined
> >> >>>>   functions, except those allowed as macros (See Section
> >> >>>>   2.6.4),
> >> >>>>   may be accessed with a name shift.
> >> >>>> 
> >> >>>> Because it says "ALLOWED as macros", MPI_Wtime may not be
> >> >>>> accessed
> >> >>>> through the profiling interface, whether or not it is
> >> >>>> implemented
> >> >>>> as a macro.  Doing so is a user error, leading to undefined
> >> >>>> behaviour.
> >> >>>> Therefore, an implementation may implement them as C inline
> >> >>>> functions,
> >> >>>> and would meet all of the requirements of MPI.
> >> >>>> 
> >> >>>> The error is more pervasive than just for Fortran.  Because
> >> >>>> it
> >> >>>> did
> >> >>>> not say what it meant, but something that was equivalent
> >> >>>> under
> >> >>>> K&R C
> >> >>>> (sic), it wasn't strictly true in C90 and was rendered
> >> >>>> significantly
> >> >>>> misleading (arguably erroneous) by C99.  And that's the
> >> >>>> reason
> >> >>>> that
> >> >>>> some people get very unhappy about the proposed partial fix.
> >> >>>> 
> >> >>>> It's also why the best solution is to regard ALL of the
> >> >>>> wording
> >> >>>> as
> >> >>>> an error - which would probably mean starting a new ticket.
> >> >>>>  But
> >> >>>> it's
> >> >>>> definitely an error in the wording, not a change.
> >> >>>> 
> >> >>>> 
> >> >>>> Regards,
> >> >>>> Nick Maclaren.
> >> >>>> 
> >> >>>> _______________________________________________
> >> >>>> mpiwg-fortran mailing list
> >> >>>> mpiwg-fortran at lists.mpi-forum.org
> >> >>>> http://lists.mpi-forum.org/mailman/listinfo.cgi/mpiwg-fortran
> >> >>>> 
> >> >>> 
> >> >>> --
> >> >>> Dr. Rolf Rabenseifner . . . . . . . . . .. email
> >> >>> rabenseifner at hlrs.de
> >> >>> High Performance Computing Center (HLRS) . phone
> >> >>> ++49(0)711/685-65530
> >> >>> University of Stuttgart . . . . . . . . .. fax ++49(0)711 /
> >> >>> 685-65832
> >> >>> Head of Dpmt Parallel Computing . . .
> >> >>> www.hlrs.de/people/rabenseifner
> >> >>> Nobelstr. 19, D-70550 Stuttgart, Germany . . . . (Office: Room
> >> >>> 1.307)
> >> >>> _______________________________________________
> >> >>> mpiwg-fortran mailing list
> >> >>> mpiwg-fortran at lists.mpi-forum.org
> >> >>> http://lists.mpi-forum.org/mailman/listinfo.cgi/mpiwg-fortran
> >> >> 
> >> >> 
> >> >> --
> >> >> Jeff Squyres
> >> >> jsquyres at cisco.com
> >> >> For corporate legal information go to:
> >> >> http://www.cisco.com/web/about/doing_business/legal/cri/
> >> >> 
> >> >> _______________________________________________
> >> >> mpiwg-tools mailing list
> >> >> mpiwg-tools at lists.mpi-forum.org
> >> >> http://lists.mpi-forum.org/mailman/listinfo.cgi/mpiwg-tools
> >> > 
> >> > 
> >> > _______________________________________________
> >> > mpiwg-fortran mailing list
> >> > mpiwg-fortran at lists.mpi-forum.org
> >> > http://lists.mpi-forum.org/mailman/listinfo.cgi/mpiwg-fortran
> >> 
> >> 
> >> --
> >> Jeff Squyres
> >> jsquyres at cisco.com
> >> For corporate legal information go to:
> >> http://www.cisco.com/web/about/doing_business/legal/cri/
> >> 
> >> _______________________________________________
> >> mpiwg-tools mailing list
> >> mpiwg-tools at lists.mpi-forum.org
> >> http://lists.mpi-forum.org/mailman/listinfo.cgi/mpiwg-tools
> >> 
> >
> >--
> >Dr. Rolf Rabenseifner . . . . . . . . . .. email
> >rabenseifner at hlrs.de
> >High Performance Computing Center (HLRS) . phone
> >++49(0)711/685-65530
> >University of Stuttgart . . . . . . . . .. fax ++49(0)711 /
> >685-65832
> >Head of Dpmt Parallel Computing . . .
> >www.hlrs.de/people/rabenseifner
> >Nobelstr. 19, D-70550 Stuttgart, Germany . . . . (Office: Room
> >1.307)
> >_______________________________________________
> >mpiwg-tools mailing list
> >mpiwg-tools at lists.mpi-forum.org
> >http://lists.mpi-forum.org/mailman/listinfo.cgi/mpiwg-tools
> 
> 
> _______________________________________________
> mpiwg-tools mailing list
> mpiwg-tools at lists.mpi-forum.org
> http://lists.mpi-forum.org/mailman/listinfo.cgi/mpiwg-tools

-- 
Dr. Rolf Rabenseifner . . . . . . . . . .. email rabenseifner at hlrs.de
High Performance Computing Center (HLRS) . phone ++49(0)711/685-65530
University of Stuttgart . . . . . . . . .. fax ++49(0)711 / 685-65832
Head of Dpmt Parallel Computing . . . www.hlrs.de/people/rabenseifner
Nobelstr. 19, D-70550 Stuttgart, Germany . . . . (Office: Room 1.307)



More information about the mpiwg-fortran mailing list