[mpiwg-tools] [MPIWG Fortran] Proposal: MPI_SIZEOF not profiled
schulzm at llnl.gov
Mon May 19 13:03:36 CDT 2014
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 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
>Is that all?
>On May 19, 2014, at 11:08 AM, Rolf Rabenseifner <rabenseifner at hlrs.de>
>> 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?
>> ----- 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
>>> On May 19 2014, Rolf Rabenseifner wrote:
>>>> 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
>>> Therefore, an implementation may implement them as C inline
>>> 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.
>>> Nick Maclaren.
>>> mpiwg-fortran mailing list
>>> mpiwg-fortran at lists.mpi-forum.org
>> 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
>jsquyres at cisco.com
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