[Mpi-forum] MPI-3: MPI_T_ERR_... and MPI_ERR_LASTCODE

Bronis R. de Supinski bronis at llnl.gov
Wed Jul 25 00:15:59 CDT 2012


Martin:

Because using the error classes wording is what caused
the original confusion. Further, your wording precludes
ever allowing an implementation to extend the return codes.

Frankly, your opinion is that calling them error classes
is less confusing but we have already seen that experts
are confused by that.

As to your second suggestion, it would be simpler if you
showed just the change to make it clearer that it is just
a ticket 0 change instead of asking people to wade through
the comparison of two lengthy passages.

Bronis






On Tue, 24 Jul 2012, Schulz, Martin wrote:

> Hi Bronis,
>
> On Jul 25, 2012, at 12:19 AM, Bronis R. de Supinski wrote:
>
>>
>> Martin:
>>
>> You are incorrect. The text in 8.4 explicitly states that
>> all error classes are error codes. My text was straightforward
>
> Yes, that's what I said as well. Error classes are a subset of error codes.
>
>> and not as long and awkward as your suggestion that attempts
>
> In the first suggestion I just replaced one word and then cut duplicate text (the new version is shorter) - your text said that all return codes are error codes and I still think this is not quite correct or at least ambiguous. We are defining their values with constants in the Table, something that we can't do for error codes that are not classes. Hence, I just suggested to replace "All return codes with the prefix MPI_T_ are error codes." with "All return codes with the prefix MPI_T_ are error classes.". Otherwise we are first saying that return codes can be (arbitrary) error codes, but then we state they should behave as classes. Why not say they are classes from the beginning?
>
>> to make a non-existent distinction. I vote for Adam's suggested
>> rationale that extended my wording.
>
> In the second suggestion, I was actually trying to get rid of the term MPI_T return codes, since this has caused the confusion. I think this is cleaner (and the text overall is actually shorter - I just quoted the whole subsection 14.3.9 for context). The text is itself is virtually unchanged from the approved ticket. However, I have said that I am fine with either version.
>
> Martin
>
>
>>
>> Bronis
>>
>>
>>
>>
>> On Tue, 24 Jul 2012, Schulz, Martin wrote:
>>
>>> I agree with Adam's rational - that is a good addition.
>>>
>>> However, I don't think the last proposal (which was, I believe in Bronis's email)
>>>
>>>>   All return codes with the prefix MPI_T_ are error codes. They must be
>>>>   unique values and cannot overlap with any other error codes or error
>>>>   classes returned by the MPI implementation. Further, they shall be
>>>>   treated as MPI error classes as defined in Chapter 8.4 and follow
>>>>   the same rules and restrictions. In particular, they must satisfy:
>>>>
>>>>      0 = MPI_SUCCESS < MPI_T_ERR_... \leq MPI_ERR_LASTCODE.
>>>
>>>
>>> is consistent with 8.4 (although that chapter is not quite consistent in itself, but that's a different issue). If we want to fully embed the MPI_T return codes into the MPI error class/code terminology (which I agree with), then MPI_T return codes are not error codes, but classes, since we are defining their values. Codes that are not classes are left to the implementation. 8.4 also states that MPI routines can return classes and that classes are a subset of codes. Hence, I think the following is correct:
>>>
>>>> All return codes with the prefix MPI_T_ are error classes. They must be
>>>> unique values and cannot overlap with any other error codes or error
>>>> classes returned by the MPI implementation. Further, they shall follow
>>>> the same rules and restrictions as defined in Chapter 8.4. In particular,
>>>> they must satisfy:
>>>>
>>>>      0 = MPI_SUCCESS < MPI_T_ERR_... \leq MPI_ERR_LASTCODE.
>>>
>>> However, this is starting to get awkward and repetitive. Hence, we may want to rewrite 14.3.9 as follows:
>>>
>>> Old text (currently in approved for 14.3.9):
>>>
>>>> All functions defined as part of the MPI tool information interface
>>>> return an integer return code (see Table 14.5) to indicate whether
>>>> the function was completed successfully or was aborted. In the
>>>> latter case the return code indicates the reason for not completing
>>>> the routine.  None of the return codes returned by an  routine
>>>> impact the execution of the MPI process and do not invoke MPI error
>>>> handlers.  The execution of the MPI process continues as if the
>>>> call would have completed. However, the \MPI/ implementation
>>>> is not required to check all user provided parameters; if a user
>>>> passes invalid parameter values to any  routine the behavior of
>>>> the implementation is undefined.
>>>>
>>>> All return codes with the prefix MPI\_T\_ must be unique values
>>>> and cannot overlap with any other return values returned by
>>>> the \MPI/ implementation.
>>>
>>> New suggested text:
>>>
>>>> All functions defined as part of the MPI tool information interface
>>>> return an MPI error class, as defined in Table 14.5, to indicate whether
>>>> the function was completed successfully or was aborted. In the
>>>> latter case the error class indicates the reason for not completing
>>>> the routine.  None of the error classes returned by an  routine
>>>> impact the execution of the MPI process and do not invoke MPI error
>>>> handlers.  The execution of the MPI process continues as if the
>>>> call would have completed. However, the MPI implementation
>>>> is not required to check all user provided parameters; if a user
>>>> passes invalid parameter values to any  routine the behavior of
>>>> the implementation is undefined.
>>>>
>>>> All MPI error classes with the prefix MPI\_T\_ must be unique values
>>>> and cannot overlap with any other error codes or error
>>>> classes returned by the MPI implementation and must follow
>>>> the same rules and restrictions laid out in Chapter 8.4. In particular,
>>>> they must satisfy:
>>>>
>>>> 0 = MPI_SUCCESS < MPI_T_ERR_... \leq MPI_ERR_LASTCODE.
>>>>
>>>> Rationale:
>>>> All MPI tool information interface functions must return error classes,
>>>> because applications cannot portably call MPI_ERROR_CLASS before
>>>> MPI_INIT or MPI_INIT_THREAD to map an arbitrary error code to an error
>>>> class.
>>>
>>> I can go either way (just making the minor change mention above and adding Adam's rational) or with the larger adjustment. I believe those two are semantically equivalent.
>>>
>>> Martin
>>>
>>>
>>>
>>> On Jul 24, 2012, at 2:31 PM, Mohror, Kathryn wrote:
>>>
>>>> I am in favor of adding Adam's rationale.
>>>>
>>>>> Rationale:
>>>>> All MPI tool information interface functions must return error classes,
>>>>> because applications cannot portably call MPI_ERROR_CLASS before
>>>>> MPI_INIT or MPI_INIT_THREAD to map an arbitrary error code to an error
>>>>> class.
>>>>
>>>> Kathryn
>>>>
>>>>> -----Original Message-----
>>>>> From: mpi-forum-bounces at lists.mpi-forum.org [mailto:mpi-forum-
>>>>> bounces at lists.mpi-forum.org] On Behalf Of Adam T. Moody
>>>>> Sent: Tuesday, July 24, 2012 11:23 AM
>>>>> To: Main MPI Forum mailing list
>>>>> Subject: Re: [Mpi-forum] MPI-3: MPI_T_ERR_... and MPI_ERR_LASTCODE
>>>>>
>>>>> I think we are all converging, but there is one point that I wanted to
>>>>> bring up:
>>>>>
>>>>>   Can one call ERROR_CLASS/STRING before MPI_INIT?
>>>>>
>>>>> The current standard doesn't allow this, since ERROR_CLASS/STRING are
>>>>> not in the list of functions that one can call before INIT.  However,
>>>>> Rolf pointed out that the previous standard didn't need to allow this,
>>>>> because there is no way to replace the default error handler (which is
>>>>> that errors are fatal) until after INIT.  Thus, if one of these
>>>>> functions throws an error before INIT, it triggers the ERRORS_ARE_FATAL
>>>>> handler and never returns.
>>>>>
>>>>> However, since MPI_T_ errors do not kick off the error handlers, now we
>>>>> have the case where error codes can be returned before MPI_INIT.
>>>>> However, again, since ERROR_CLASS/STRING are not in the list of
>>>>> functions that one can call before INIT, it is implied that users cannot
>>>>> call these functions until after MPI_INIT.  It would be nice to add a
>>>>> rationale statement along these lines to the latest proposed text, e.g.:
>>>>>
>>>>>
>>>>> All return codes with the prefix MPI_T_ are error codes. They must be
>>>>> unique values and cannot overlap with any other error codes or error
>>>>> classes returned by the MPI implementation. Further, they shall be
>>>>> treated as MPI error classes as defined in Chapter 8.4 and follow
>>>>> the same rules and restrictions. In particular, they must satisfy:
>>>>>
>>>>> 0 = MPI_SUCCESS < MPI_T_ERR_... \leq MPI_ERR_LASTCODE.
>>>>>
>>>>> Rationale:
>>>>> All MPI tool information interface functions must return error classes,
>>>>> because applications cannot portably call MPI_ERROR_CLASS before
>>>>> MPI_INIT or MPI_INIT_THREAD to map an arbitrary error code to an error
>>>>> class.
>>>>>
>>>>>
>>>>> Note the above is more restrictive than it needs to be, since it seems
>>>>> that we could allow MPI_T to return arbitrary error codes *after*
>>>>> MPI_INIT.  However, it seems we're already imposing the restriction that
>>>>> they always return error classes.
>>>>> -Adam
>>>>>
>>>>>
>>>>>
>>>>> Mohror, Kathryn wrote:
>>>>>
>>>>>> I see the meaning of classes and codes now. I was a bit confused by the
>>>>> wording in 8.4. I still think it's a bit weird that everywhere else in the standard,
>>>>> the codes returned need to be converted to classes to get a portable
>>>>> understanding of the error, but in MPI_T we will return classes, so the meaning
>>>>> is already known without conversion.
>>>>>>
>>>>>> However, that said, Bronis' wording of Rolf's suggested change seems to
>>>>> make that distinction clearer. I am okay with Bronis' text:
>>>>>>
>>>>>>
>>>>>>
>>>>>>> All return codes with the prefix MPI_T_ are error codes. They must be
>>>>>>>  unique values and cannot overlap with any other error codes or error
>>>>>>>  classes returned by the MPI implementation. Further, they shall be
>>>>>>>  treated as MPI error classes as defined in Chapter 8.4 and follow
>>>>>>>  the same rules and restrictions. In particular, they must satisfy:
>>>>>>>
>>>>>>>     0 = MPI_SUCCESS < MPI_T_ERR_... \leq MPI_ERR_LASTCODE.
>>>>>>>
>>>>>>>
>>>>>>
>>>>>> Kathryn
>>>>>>
>>>>>>
>>>>>>
>>>>>>> -----Original Message-----
>>>>>>> From: mpi-forum-bounces at lists.mpi-forum.org [mailto:mpi-forum-
>>>>>>> bounces at lists.mpi-forum.org] On Behalf Of William Gropp
>>>>>>> Sent: Tuesday, July 24, 2012 8:31 AM
>>>>>>> To: Main MPI Forum mailing list
>>>>>>> Subject: Re: [Mpi-forum] MPI-3: MPI_T_ERR_... and MPI_ERR_LASTCODE
>>>>>>>
>>>>>>> MPI error codes, combined with MPI_Error_string, permit an MPI
>>>>>>> implementation to return a instance-specific and detailed error message.
>>>>> Error
>>>>>>> classes, like Unix error codes, have only slightly more information that
>>>>>>> "something went wrong".
>>>>>>>
>>>>>>> Because MPI error classes are error codes, its possible to return the error
>>>>> class;
>>>>>>> this can be used before Init and after Finalize now.  But between Init and
>>>>>>> Finalize, codes permit but do not require an implementation to return more
>>>>>>> helpful information.  I see no reason to require the MPI_T interface to be
>>>>> less
>>>>>>> user-friendly than the rest of the MPI interface.  However, leaving this for
>>>>> 3.1
>>>>>>> might make sense.
>>>>>>>
>>>>>>> Bill
>>>>>>>
>>>>>>> William Gropp
>>>>>>> Director, Parallel Computing Institute
>>>>>>> Deputy Director for Research
>>>>>>> Institute for Advanced Computing Applications and Technologies
>>>>>>> Paul and Cynthia Saylor Professor of Computer Science
>>>>>>> University of Illinois Urbana-Champaign
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> On Jul 23, 2012, at 3:05 PM, Mohror, Kathryn wrote:
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>> I have some concerns over this.
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>>> The topic about user-callability of MPI_ERROR_CLASS and
>>>>>>>>>
>>>>>>>>>
>>>>>>> MPI_ERROR_STRING
>>>>>>>
>>>>>>>
>>>>>>>>> outside of the initialized MPI should be revisited in MPI-3.1.
>>>>>>>>> This is not evident for the tools' developers because they know
>>>>>>>>> the meaning of their MPI_T_ERR... classes and only classes are returned.
>>>>>>>>>
>>>>>>>>>
>>>>>>>> If we are going to treat MPI_T error codes the same way they are in the rest
>>>>> of
>>>>>>>>
>>>>>>>>
>>>>>>> the standard, does it make sense to say that "only classes are returned" by
>>>>>>> MPI_T calls? I think that MPI calls return codes and the codes are translated
>>>>> to
>>>>>>> classes by the MPI_ERROR_CLASS function.
>>>>>>>
>>>>>>>
>>>>>>>> If MPI_ERROR_CLASS and MPI_ERROR_STRING are not available before
>>>>>>>>
>>>>>>>>
>>>>>>> MPI_Init, then this may be a hardship on tools. I imagine many tools doing a
>>>>>>> significant amount of set up before MPI_Init to avoid overhead. However, if
>>>>>>> there is no information about what the return codes mean, then tools may
>>>>> have
>>>>>>> difficulty.
>>>>>>>
>>>>>>>
>>>>>>>> Possibly it makes more sense to treat MPI_T return values differently than
>>>>>>>>
>>>>>>>>
>>>>>>> MPI calls? Could the MPI_T return values be a set of defined codes instead?
>>>>>>>
>>>>>>>
>>>>>>>> Does anyone have different insight on error codes vs classes?
>>>>>>>>
>>>>>>>> Kathryn
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>>> -----Original Message-----
>>>>>>>>> From: mpi-forum-bounces at lists.mpi-forum.org [mailto:mpi-forum-
>>>>>>>>> bounces at lists.mpi-forum.org] On Behalf Of Bronis R. de Supinski
>>>>>>>>> Sent: Monday, July 23, 2012 10:37 AM
>>>>>>>>> To: Main MPI Forum mailing list
>>>>>>>>> Subject: Re: [Mpi-forum] MPI-3: MPI_T_ERR_... and MPI_ERR_LASTCODE
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> OK by me.
>>>>>>>>>
>>>>>>>>> On Mon, 23 Jul 2012, Dave Goodell wrote:
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>> I agree, we should make these changes.
>>>>>>>>>>
>>>>>>>>>> -Dave
>>>>>>>>>>
>>>>>>>>>> On Jul 23, 2012, at 8:55 AM CDT, Schulz, Martin wrote:
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>> Hi Rolf, all,
>>>>>>>>>>>
>>>>>>>>>>> I agree with your suggestions and I am in favor of making these
>>>>> changes.
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>> Bronis (as well as Kathryn and Dave as the remaining members in the
>>>>>>>>>
>>>>>>>>>
>>>>>>> chapter
>>>>>>>
>>>>>>>
>>>>>>>>> committee for tools) should concur, though.
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>>> Anybody else have any concerns over these changes?
>>>>>>>>>>>
>>>>>>>>>>> As for the callability of the error functions, I also agree - let's target
>>>>> those
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>> in
>>>>>>>
>>>>>>>
>>>>>>>>> 3.1. This change is not vital and bit too big for final edits.
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>>> Thanks,
>>>>>>>>>>>
>>>>>>>>>>> Martin
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>> On Jul 23, 2012, at 4:00 AM, Rolf Rabenseifner wrote:
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>>> Martin et al.,
>>>>>>>>>>>>
>>>>>>>>>>>> Consistently with your proposal, I would recommend:
>>>>>>>>>>>>
>>>>>>>>>>>> 1) Sect 14.3.9 "Return Codes for the MPI tool information interface"
>>>>>>>>>>>> last sentence reads
>>>>>>>>>>>>
>>>>>>>>>>>> All return codes with the prefix MPI_T_ must be unique values and
>>>>>>>>>>>> cannot overlap with any other return values returned by the MPI
>>>>>>>>>>>> implementation.
>>>>>>>>>>>>
>>>>>>>>>>>> but should read
>>>>>>>>>>>>
>>>>>>>>>>>>
>>>>>>>>>>>>
>>>>>>>>>>>>> All return codes with the prefix MPI_T_ must be unique values and
>>>>>>>>>>>>> cannot overlap with any other
>>>>>>>>>>>>>
>>>>>>>>>>>>>
>>>>>>>>>>>> error codes and error classes
>>>>>>>>>>>>
>>>>>>>>>>>>
>>>>>>>>>>>>> returned by the MPI
>>>>>>>>>>>>> implementation. Further, they shall be treated as MPI error classes
>>>>> as
>>>>>>>>>>>>> defined in Chapter 8.4 and follow the same rules and restrictions,
>>>>>>>>>>>>>
>>>>>>>>>>>>>
>>>>>>>>>>>> especially they must satisfy
>>>>>>>>>>>>
>>>>>>>>>>>>
>>>>>>>>>>>>
>>>>>>>>>>>>>>>>> 0 = MPI_SUCCESS < MPI_T_ERR_... \leq MPI_ERR_LASTCODE.
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>> 2) A.1.1 the first three tables are headed by
>>>>>>>>>>>>
>>>>>>>>>>>> Error classes
>>>>>>>>>>>> Error classes (continued)
>>>>>>>>>>>> Return Codes for the MPI tool information interface
>>>>>>>>>>>>
>>>>>>>>>>>> and these lines should read
>>>>>>>>>>>>
>>>>>>>>>>>> Error classes
>>>>>>>>>>>> Error classes (continued)
>>>>>>>>>>>> Error classes (continued)
>>>>>>>>>>>>
>>>>>>>>>>>> 3) The last line of A.1.1, 2nd table
>>>>>>>>>>>>
>>>>>>>>>>>> MPI_ERR_LASTCODE
>>>>>>>>>>>>
>>>>>>>>>>>> should move after the last MPI_T_ERR_... code in the 3rd table.
>>>>>>>>>>>>
>>>>>>>>>>>> Okay?
>>>>>>>>>>>>
>>>>>>>>>>>> The topic about user-callability of MPI_ERROR_CLASS and
>>>>>>>>>>>>
>>>>>>>>>>>>
>>>>>>>>> MPI_ERROR_STRING
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>>>> outside of the initialized MPI should be revisited in MPI-3.1.
>>>>>>>>>>>> This is not evident for the tools' developers because they know
>>>>>>>>>>>> the meaning of their MPI_T_ERR... classes and only classes are
>>>>> returned.
>>>>>>>>>>>>
>>>>>>>>>>>> I would like to have a final "okay" before I execute
>>>>>>>>>>>> the changes in chap-appLang.
>>>>>>>>>>>>
>>>>>>>>>>>> Best regards
>>>>>>>>>>>> Rolf
>>>>>>>>>>>>
>>>>>>>>>>>> ----- Original Message -----
>>>>>>>>>>>>
>>>>>>>>>>>>
>>>>>>>>>>>>> From: "Martin Schulz" <schulzm at llnl.gov>
>>>>>>>>>>>>> To: "Main MPI Forum mailing list" <mpi-forum at lists.mpi-forum.org>
>>>>>>>>>>>>> Sent: Monday, July 23, 2012 1:23:40 AM
>>>>>>>>>>>>> Subject: Re: [Mpi-forum] MPI-3: MPI_T_ERR_... and
>>>>>>>>>>>>>
>>>>>>>>>>>>>
>>>>>>>>> MPI_ERR_LASTCODE
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>>>>> Hi Rolf, all,
>>>>>>>>>>>>>
>>>>>>>>>>>>> I thought we had discussed the error semantics of MPI_T in several
>>>>>>>>>>>>> meetings/readings and nobody objected, but I generally agree with
>>>>>>>>>>>>>
>>>>>>>>>>>>>
>>>>>>> your
>>>>>>>
>>>>>>>
>>>>>>>>>>>>> comments below. However, they are not really error classes (at least
>>>>>>>>>>>>> in the tools group we/I never thought about them this way), but just
>>>>>>>>>>>>> well defined return codes. Nevertheless, they fit the model and
>>>>>>>>>>>>> semantics of classes and hence should integrated into the same rules
>>>>>>>>>>>>> for consistency. I also agree with Bronis, though, that larger
>>>>>>>>>>>>> feedback on this would be good to avoid errors because of rushing it.
>>>>>>>>>>>>>
>>>>>>>>>>>>> To keep changes minimal, I would suggest that we only change the
>>>>>>>>>>>>> following sentence, which IMHO is sufficient (and would essentially
>>>>>>>>>>>>> follow option b):
>>>>>>>>>>>>>
>>>>>>>>>>>>> All return codes with the prefix MPI_T_ must be unique values and
>>>>>>>>>>>>> cannot overlap with any other return values returned by the MPI
>>>>>>>>>>>>> implementation. Further, they shall be treated as MPI error classes
>>>>> as
>>>>>>>>>>>>> defined in Chapter 8.4 and follow the same rules and restrictions.
>>>>>>>>>>>>>
>>>>>>>>>>>>> This would also make changes in the appendix unnecessary.
>>>>>>>>>>>>>
>>>>>>>>>>>>> As for making MPI_ERROR_CLASS and MPI_ERROR_STRING
>>>>> callable
>>>>>>>>>>>>>
>>>>>>>>>>>>>
>>>>>>>>> before
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>>>>> Init (and then also after finalize), yes that would be very useful,
>>>>>>>>>>>>> but is a general issue not only related to MPI_T. If we decide this is
>>>>>>>>>>>>> too invasive at this point, I would like to see this at least in 3.1.
>>>>>>>>>>>>>
>>>>>>>>>>>>> Martin
>>>>>>>>>>>>>
>>>>>>>>>>>>>
>>>>>>>>>>>>>
>>>>>>>>>>>>>
>>>>>>>>>>>>> On Jul 22, 2012, at 1:46 PM, Rolf Rabenseifner wrote:
>>>>>>>>>>>>>
>>>>>>>>>>>>>
>>>>>>>>>>>>>
>>>>>>>>>>>>>> About 1. question:
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> I changed the headers of the three error code tables in the Annex
>>>>>>>>>>>>>> according to Tables 8.1 and 8.2 from "Return codes"
>>>>>>>>>>>>>> into "Error classes".
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> svn r1505: I used also "Error classes" for the tools table
>>>>>>>>>>>>>> svn r1507: I went back to the official ticket 266 text "Return
>>>>>>>>>>>>>> codes"
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> The Tools group should decide whether
>>>>>>>>>>>>>> a. they want to stay with special return codes that are not
>>>>>>>>>>>>>> part of the rule in Set. 8.4
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> 0 = MPI_SUCCESS < MPI_ERR_... <= MPI_ERR_LASTCODE
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> In this case they should change "return code"
>>>>>>>>>>>>>> into "error codes are returned" plus noting that
>>>>>>>>>>>>>> the routine MPI_ERROR_STRING can be applied
>>>>>>>>>>>>>> with the open question, whether MPI_EEROR_STRING
>>>>>>>>>>>>>> can be applied before a call to MPI_INIT.
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> Similar problem with failed MPI_INIT and analysing its
>>>>>>>>>>>>>> returned error code:
>>>>>>>>>>>>>> One needs at least MPI_ERROR_CLASS and MPI_ERROR_STRING
>>>>>>>>>>>>>> callable before MPI_INIT.
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> b. or you may use the same terminology as in Sect. 8.4,
>>>>>>>>>>>>>> then new table 14.5 must show "Error classes".
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> In this case you should integrate the MPI_T_ERR_...
>>>>>>>>>>>>>> into the MPI_ERR_LASTCODE rule.
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> You need at least MPI_ERROR_CLASS and MPI_ERROR_STRING
>>>>>>>>>>>>>> callable before MPI_INIT.
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> I would prefer solution b together combined with the
>>>>>>>>>>>>>> minimal solution for failed MPI_INIT, i.e.,
>>>>>>>>>>>>>> adding MPI_ERROR_CLASS and MPI_ERROR_STRING to
>>>>>>>>>>>>>> the list of routines callable outside of MPI's
>>>>>>>>>>>>>> initialization.
>>>>>>>>>>>>>>
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> About 2. question: MPI_T_ERR_CANTINIT -_>
>>>>>>>>>>>>>>
>>>>>>>>>>>>>>
>>>>>>>>> MPI_T_ERR_CANNOTINIT
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>>>>>> svn r1506: done by Bronis in chap-tools/mpit.tex
>>>>>>>>>>>>>> svn r1508: done by Rolf in chap-appLang/appLang-Const.tex
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> Rolf
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> ----- Original Message -----
>>>>>>>>>>>>>>
>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> From: "Bronis R. de Supinski" <bronis at llnl.gov>
>>>>>>>>>>>>>>> To: "Main MPI Forum mailing list" <mpi-forum at lists.mpi-
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>
>>>>>>> forum.org>
>>>>>>>
>>>>>>>
>>>>>>>>>>>>>>> Cc: "Rolf Rabenseifner" <rabenseifner at hlrs.de>
>>>>>>>>>>>>>>> Sent: Sunday, July 22, 2012 10:03:44 PM
>>>>>>>>>>>>>>> Subject: Re: [Mpi-forum] MPI-3: MPI_T_ERR_... and
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>
>>>>>>>>> MPI_ERR_LASTCODE
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>>>>>>> Rolf:
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> OK, I am changing MPI_T_ERR_CANTINIT to
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>
>>>>>>>>> MPI_T_ERR_CANNOTINIT.
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>>>>>>> As said before, we need more opinions on the first question.
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> Bronis
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> On Sun, 22 Jul 2012, Bronis R. de Supinski wrote:
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> Rolf:
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> Re:
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>> Dear Bronis, Martin, Dave, and Kathryn,
>>>>>>>>>>>>>>>>> (Profiling/Tools chapter responsibles)
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>> (you may forward this to the tools list - I'm not on that list)
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>> Two important questions:
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>> 1. Alexander Supalov detected that we did it wrong:
>>>>>>>>>>>>>>>>> The MPI_T_ERR_... list must be part of the total error
>>>>>>>>>>>>>>>>> list and sorted in before MPI_ERR_LASTCODE.
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>> I will change this in chap-appLang/appLang-Const.tex
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>> Please look, if there must be some additional wording on this.
>>>>>>>>>>>>>>>>> For example, the last sentence of Section 14.3.9
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>> "All return codes with the prefix MPI_T_ must be unique values
>>>>>>>>>>>>>>>>> and
>>>>>>>>>>>>>>>>> cannot overlap with any other return values returned by the
>>>>> MPI
>>>>>>>>>>>>>>>>> implementation."
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> The above wording clearly states that the return values
>>>>>>>>>>>>>>>> should be consistent with MPI_ERR_* return values. So,
>>>>>>>>>>>>>>>> either the above wording needs to change (I do not see
>>>>>>>>>>>>>>>> why MPI_T_* return values need to be distinct from
>>>>>>>>>>>>>>>> MPI_ERR_* return values since the user should know that
>>>>>>>>>>>>>>>> they were using an MPI_T_* function) or we need to adopt
>>>>>>>>>>>>>>>> something like what you suggest.
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> I think we need broader opinions to make the decision.
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> I am concerned that wrapping up the document for MPI 3.0
>>>>>>>>>>>>>>>> has led to a fast and loose attitude about making broader
>>>>>>>>>>>>>>>> changes "in order to get it done." This attitude can
>>>>>>>>>>>>>>>> easily lead to suboptimal solutions.
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> Bronis
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>> may be modified into
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>> "All return codes with the prefix MPI_T_ must be unique values
>>>>>>>>>>>>>>>>> and
>>>>>>>>>>>>>>>>> cannot overlap with any other return values returned by the
>>>>> MPI
>>>>>>>>>>>>>>>>> implementation and satisfy
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>> 0 = MPI_SUCCESS < MPI_T_ERR_... <= MPI_ERR_LASTCODE. "
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>> or
>>>>>>>>>>>>>>>>> 0 = MPI_SUCCESS < MPI_ERR_... < MPI_T_ERR_... <=
>>>>>>>>>>>>>>>>> MPI_ERR_LASTCODE.
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>> or
>>>>>>>>>>>>>>>>> 0 = MPI_SUCCESS < MPI_ERR_... <= MPI_ERR_LASTCODE <
>>>>>>>>>>>>>>>>> MPI_T_ERR_... <= MPI_T_ERR_LASTCODE.
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>> and the MPI_ERR_LASTCODE and/or MPI_T_ERR_LASTCODE
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>
>>>>>>> may
>>>>>>>
>>>>>>>
>>>>>>>>> be also
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>>>>>>>>> repeated
>>>>>>>>>>>>>>>>> in Table 14.5 as last entry, as done for the first value
>>>>>>>>>>>>>>>>> MPI_SUCCESS.
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>> This proposal is based on Section 8.4, the sentence
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>> "The error codes satisfy,
>>>>>>>>>>>>>>>>> 0 = MPI_SUCCESS < MPI_ERR_... <= MPI_ERR_LASTCODE: "
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>> Please confirm, that Alexander is right,
>>>>>>>>>>>>>>>>> please include me in your discussion and
>>>>>>>>>>>>>>>>> please tell me your result
>>>>>>>>>>>>>>>>> that I can do the correct changes in chap-appLang
>>>>>>>>>>>>>>>>> and you in chap-tools.
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>> 2. Qeustion is less important; it is about naming:
>>>>>>>>>>>>>>>>> Alexander also noticed that your names do not fit to the names
>>>>>>>>>>>>>>>>> used in the past:
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>> MPI_T_ERR_CANTINIT --> MPI_T_ERR_CANNOTINIT (we do
>>>>> not
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>
>>>>>>> use
>>>>>>>
>>>>>>>
>>>>>>>>>>>>>>>>> abbrevations)
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>> or
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>> MPI_T_ERR_CANTINIT --> MPI_T_ERR_CANNOT_INIT (we do
>>>>> not
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>
>>>>>>>>> use
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>>>>>>>>> abbrevations)
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>> In most cases, we do not combine words without underscore.
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>> As far as I see, you can do the underscores.
>>>>>>>>>>>>>>>>> Be sure to stay at maximum with 30 characters.
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>> Current longest MPI_T constants:
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>> 123456789012345678901234567890
>>>>>>>>>>>>>>>>> MPI_T_PVAR_CLASS_HIGHWATERMARK
>>>>>>>>>>>>>>>>> MPI_T_PVAR_CLASS_LOWWATERMARK
>>>>>>>>>>>>>>>>> MPI_T_VERBOSITY_MPIDEV_DETAIL
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>> Based on this, I would stay with you names based on your MPI_T
>>>>>>>>>>>>>>>>> rule:
>>>>>>>>>>>>>>>>> MPI_T_<structual-areas-with-underscores>_<final-name-
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>
>>>>>>> without-
>>>>>>>
>>>>>>>
>>>>>>>>> underscores>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>>>>>>>>> i.e., I would only change
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>> MPI_T_ERR_CANTINIT --> MPI_T_ERR_CANNOTINIT
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>> Please tell me also your decision
>>>>>>>>>>>>>>>>> that I can do the correct changes in chap-appLang
>>>>>>>>>>>>>>>>> and you in chap-tools.
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>> Best regards
>>>>>>>>>>>>>>>>> Rolf
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>> --
>>>>>>>>>>>>>>>>> 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: Allmandring
>>>>>>>>>>>>>>>>> 30)
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> _______________________________________________
>>>>>>>>>>>>>>>> mpi-forum mailing list
>>>>>>>>>>>>>>>> mpi-forum at lists.mpi-forum.org
>>>>>>>>>>>>>>>> http://lists.mpi-forum.org/mailman/listinfo.cgi/mpi-forum
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>> --
>>>>>>>>>>>>>> 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: Allmandring 30)
>>>>>>>>>>>>>> _______________________________________________
>>>>>>>>>>>>>> mpi-forum mailing list
>>>>>>>>>>>>>> mpi-forum at lists.mpi-forum.org
>>>>>>>>>>>>>> http://lists.mpi-forum.org/mailman/listinfo.cgi/mpi-forum
>>>>>>>>>>>>>>
>>>>>>>>>>>>>>
>>>>>>>>>>>>>
>>>>>>>>>>>>>
>>>>>>> ____________________________________________________________________
>>>>> __
>>>>>>>
>>>>>>>
>>>>>>>>> __
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>>>>> Martin Schulz, schulzm at llnl.gov, http://people.llnl.gov/schulzm
>>>>>>>>>>>>> CASC @ Lawrence Livermore National Laboratory, Livermore, USA
>>>>>>>>>>>>>
>>>>>>>>>>>>>
>>>>>>>>>>>>>
>>>>>>>>>>>>>
>>>>>>>>>>>>> _______________________________________________
>>>>>>>>>>>>> mpi-forum mailing list
>>>>>>>>>>>>> mpi-forum at lists.mpi-forum.org
>>>>>>>>>>>>> http://lists.mpi-forum.org/mailman/listinfo.cgi/mpi-forum
>>>>>>>>>>>>>
>>>>>>>>>>>>>
>>>>>>>>>>>> --
>>>>>>>>>>>> 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: Allmandring 30)
>>>>>>>>>>>>
>>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>> ____________________________________________________________________
>>>>> __
>>>>>>>
>>>>>>>
>>>>>>>>> __
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>>> Martin Schulz, schulzm at llnl.gov, http://people.llnl.gov/schulzm
>>>>>>>>>>> CASC @ Lawrence Livermore National Laboratory, Livermore, USA
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>> _______________________________________________
>>>>>>>>>>> mpi-forum mailing list
>>>>>>>>>>> mpi-forum at lists.mpi-forum.org
>>>>>>>>>>> http://lists.mpi-forum.org/mailman/listinfo.cgi/mpi-forum
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>> _______________________________________________
>>>>>>>>>> mpi-forum mailing list
>>>>>>>>>> mpi-forum at lists.mpi-forum.org
>>>>>>>>>> http://lists.mpi-forum.org/mailman/listinfo.cgi/mpi-forum
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>> _______________________________________________
>>>>>>>>> mpi-forum mailing list
>>>>>>>>> mpi-forum at lists.mpi-forum.org
>>>>>>>>> http://lists.mpi-forum.org/mailman/listinfo.cgi/mpi-forum
>>>>>>>>>
>>>>>>>>>
>>>>>>>> _______________________________________________
>>>>>>>> mpi-forum mailing list
>>>>>>>> mpi-forum at lists.mpi-forum.org
>>>>>>>> http://lists.mpi-forum.org/mailman/listinfo.cgi/mpi-forum
>>>>>>>>
>>>>>>>>
>>>>>>> _______________________________________________
>>>>>>> mpi-forum mailing list
>>>>>>> mpi-forum at lists.mpi-forum.org
>>>>>>> http://lists.mpi-forum.org/mailman/listinfo.cgi/mpi-forum
>>>>>>>
>>>>>>>
>>>>>>
>>>>>> _______________________________________________
>>>>>> mpi-forum mailing list
>>>>>> mpi-forum at lists.mpi-forum.org
>>>>>> http://lists.mpi-forum.org/mailman/listinfo.cgi/mpi-forum
>>>>>>
>>>>>>
>>>>>
>>>>> _______________________________________________
>>>>> mpi-forum mailing list
>>>>> mpi-forum at lists.mpi-forum.org
>>>>> http://lists.mpi-forum.org/mailman/listinfo.cgi/mpi-forum
>>>>
>>>> _______________________________________________
>>>> mpi-forum mailing list
>>>> mpi-forum at lists.mpi-forum.org
>>>> http://lists.mpi-forum.org/mailman/listinfo.cgi/mpi-forum
>>>
>>> ________________________________________________________________________
>>> Martin Schulz, schulzm at llnl.gov, http://people.llnl.gov/schulzm
>>> CASC @ Lawrence Livermore National Laboratory, Livermore, USA
>>>
>>>
>>>
>>>
>>> _______________________________________________
>>> mpi-forum mailing list
>>> mpi-forum at lists.mpi-forum.org
>>> http://lists.mpi-forum.org/mailman/listinfo.cgi/mpi-forum
>>>
>
> ________________________________________________________________________
> Martin Schulz, schulzm at llnl.gov, http://people.llnl.gov/schulzm
> CASC @ Lawrence Livermore National Laboratory, Livermore, USA
>
>
>
>



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