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

Martin Schulz schulzm at llnl.gov
Wed May 21 02:20:06 CDT 2014 

I fully agree - we won’t have all people at the meeting, but I have
already added the ticket to the tools WG slot and we’ll come up with at
least a draft that we can discuss via email after the meeting. The earlier
we get this done, the better.

Martin


________________________________________________________________________
Martin Schulz, schulzm at llnl.gov, http://scalability.llnl.gov/
CASC @ Lawrence Livermore National Laboratory, Livermore, USA








On 5/21/14, 12:11 AM, "Rolf Rabenseifner" <rabenseifner at hlrs.de> wrote:

>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)
>_______________________________________________
>mpiwg-tools mailing list
>mpiwg-tools at lists.mpi-forum.org
>http://lists.mpi-forum.org/mailman/listinfo.cgi/mpiwg-tools

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