Re: [mpiwg-tools] [MPIWG Fortran] Proposal: MPI_SIZEOF not profiled
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" <[email protected]> To: [email protected] Cc: "MPI-WG Fortran working group" <[email protected]> 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, [email protected], http://scalability.llnl.gov/ CASC @ Lawrence Livermore National Laboratory, Livermore, USA
On 5/19/14, 1:49 PM, "Rolf Rabenseifner" <[email protected]> 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)" <[email protected]> To: "MPI-WG Fortran working group" <[email protected]> Cc: [email protected] 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 <[email protected]> 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, [email protected], http://scalability.llnl.gov/ CASC @ Lawrence Livermore National Laboratory, Livermore, USA
On 5/19/14, 8:35 AM, "Jeff Squyres (jsquyres)" <[email protected]> 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 <[email protected]> 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" <[email protected]> To: "MPI-WG Fortran working group" <[email protected]> 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.
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-- Dr. Rolf Rabenseifner . . . . . . . . . .. email [email protected] 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 [email protected] http://lists.mpi-forum.org/mailman/listinfo.cgi/mpiwg-fortran
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-- Dr. Rolf Rabenseifner . . . . . . . . . .. email [email protected] 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 [email protected] http://lists.mpi-forum.org/mailman/listinfo.cgi/mpiwg-tools
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-- Dr. Rolf Rabenseifner . . . . . . . . . .. email [email protected] 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)
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Rolf Rabenseifner