[mpiwg-rma] Changes to the RMA chapter

Wed Mar 4 18:30:41 CST 2015

>>>>>>> 1. This is a backward incompatible change (as in, applications were not required
>>>>>>> to give the same value earlier), though folks understood why this is needed.
>>>>>>> They were OK as long as we add a Errata/Changelog item saying so.

Yes, please send me the errata changelog entry. Proposal:

Existing changelog entry

  9. Section 11.2.2 on page 405, and MPI-3.0 Section 11.2.2 on page 407.
     The same_size info key can be used with all window flavors.

should be modified into

  9. Section 11.2.1 on page xxx, and MPI-3.0 Section 11.2.2 on page 407.
     The same_size info key can be used with all window flavors,
     and requires that all processes have provided this info key 
     with the same value.

Okay so?

Best regards
Rolf

----- Original Message -----
> From: "wgropp" <wgropp at illinois.edu>
> To: "MPI WG Remote Memory Access working group" <mpiwg-rma at lists.mpi-forum.org>
> Sent: Thursday, March 5, 2015 12:26:04 AM
> Subject: Re: [mpiwg-rma] Changes to the RMA chapter

> Actually, I think the wording is clear - no process will target that particular
> window (not window object) with passive target synchronization.  Thus, as noted
> in the description, no async handing for passive RMA is needed at this process.
> It says nothing about whether this process can issue locks against some other
> process’s window.
> 
> Bill
> 
> On Mar 4, 2015, at 5:17 PM, Balaji, Pavan <balaji at anl.gov> wrote:
> 
>> 
>> If the intention is that it can be local, then the info needs to specify whether
>> it means the process cannot issue locks or whether other processes cannot issue
>> locks on it.  Either way, some change is required.  I agree this is not
>> ticket-0, and will tell the Forum that the RMA WG will put it on the list of
>> things to discuss.  We should do a WG telecon.  A number of issues are queued
>> up for discussion at this point.
>> 
>>  -- Pavan
>> 
>>> On Mar 4, 2015, at 5:09 PM, William Gropp <wgropp at illinois.edu> wrote:
>>> 
>>> For the bigger one, yes, this is much harder and absolutely not ticket-0.
>>> no_locks is particularly tricky, because it applies to the window, not the
>>> window object, and hence is defined as local.
>>> 
>>> Bill
>>> 
>>> On Mar 4, 2015, at 4:59 PM, Balaji, Pavan <balaji at anl.gov> wrote:
>>> 
>>>> 
>>>> There are two questions below.  The formatting part (whether to use [SAME]) is a
>>>> smaller issue.  The bigger issue is whether we want to say that all the
>>>> remaining info keys no_locks, etc., should be the same on all processes.
>>>> 
>>>> I want to say that, but: (1) need the chapter committee consensus, and (2) I'm
>>>> not sure it's a ticket-0 change, though we did make that change for same_size
>>>> as ticket-0.
>>>> 
>>>> -- Pavan
>>>> 
>>>>> On Mar 4, 2015, at 4:56 PM, William Gropp <wgropp at illinois.edu> wrote:
>>>>> 
>>>>> That’s an excellent idea - we should use the same language throughout the
>>>>> standard, and the I/O chapter is probably the best source.
>>>>> 
>>>>> Bill
>>>>> 
>>>>> On Mar 4, 2015, at 4:39 PM, Balaji, Pavan <balaji at anl.gov> wrote:
>>>>> 
>>>>>> 
>>>>>> Nathan suggested to use the I/O chapter format where info keys are annotated
>>>>>> with "[SAME]" to indicate that all processes must provide the same info key.
>>>>>> That is probably a ticket-0 change.  We need to first agree on whether we want
>>>>>> to do this.
>>>>>> 
>>>>>> -- Pavan
>>>>>> 
>>>>>>> On Mar 4, 2015, at 4:37 PM, Balaji, Pavan <balaji at anl.gov> wrote:
>>>>>>> 
>>>>>>> 
>>>>>>> Folks at Forum complained about the addition to the "same_size" info key which
>>>>>>> added the following phrase:
>>>>>>> 
>>>>>>> "and that all processes have provided this info key with the same value"
>>>>>>> 
>>>>>>> (this change was not a part of any ticket, and was made by the chapter
>>>>>>> committee)
>>>>>>> 
>>>>>>> There were two concerns:
>>>>>>> 
>>>>>>> 1. This is a backward incompatible change (as in, applications were not required
>>>>>>> to give the same value earlier), though folks understood why this is needed.
>>>>>>> They were OK as long as we add a Errata/Changelog item saying so.
>>>>>>> 
>>>>>>> 2. The property that all processes should give the same info key was true for
>>>>>>> other keys in that section as well (no_locks, accumulate_ordering,
>>>>>>> accumulate_ops).  So the same sentence should be added to them as well.
>>>>>>> 
>>>>>>> The Forum wants to see a draft of these changes.  I'd like to propose adding the
>>>>>>> same phrase ("and that all processes have provided this info key with the same
>>>>>>> value") to the other info keys as well.  What do folks think?  Is this
>>>>>>> something that we agree on (technically, it is possible to have different info
>>>>>>> keys in the job, but it probably doesn't make much sense).
>>>>>>> 
>>>>>>> Thoughts?
>>>>>>> 
>>>>>>> -- Pavan
>>>>>>> 
>>>>>>> --
>>>>>>> Pavan Balaji  ✉️
>>>>>>> http://www.mcs.anl.gov/~balaji
>>>>>>> 
>>>>>>> _______________________________________________
>>>>>>> mpiwg-rma mailing list
>>>>>>> mpiwg-rma at lists.mpi-forum.org
>>>>>>> http://lists.mpi-forum.org/mailman/listinfo.cgi/mpiwg-rma
>>>>>> 
>>>>>> --
>>>>>> Pavan Balaji  ✉️
>>>>>> http://www.mcs.anl.gov/~balaji
>>>>>> 
>>>>>> _______________________________________________
>>>>>> mpiwg-rma mailing list
>>>>>> mpiwg-rma at lists.mpi-forum.org
>>>>>> http://lists.mpi-forum.org/mailman/listinfo.cgi/mpiwg-rma
>>>>> 
>>>>> _______________________________________________
>>>>> mpiwg-rma mailing list
>>>>> mpiwg-rma at lists.mpi-forum.org
>>>>> http://lists.mpi-forum.org/mailman/listinfo.cgi/mpiwg-rma
>>>> 
>>>> --
>>>> Pavan Balaji  ✉️
>>>> http://www.mcs.anl.gov/~balaji
>>>> 
>>>> _______________________________________________
>>>> mpiwg-rma mailing list
>>>> mpiwg-rma at lists.mpi-forum.org
>>>> http://lists.mpi-forum.org/mailman/listinfo.cgi/mpiwg-rma
>>> 
>>> _______________________________________________
>>> mpiwg-rma mailing list
>>> mpiwg-rma at lists.mpi-forum.org
>>> http://lists.mpi-forum.org/mailman/listinfo.cgi/mpiwg-rma
>> 
>> --
>> Pavan Balaji  ✉️
>> http://www.mcs.anl.gov/~balaji
>> 
>> _______________________________________________
>> mpiwg-rma mailing list
>> mpiwg-rma at lists.mpi-forum.org
>> http://lists.mpi-forum.org/mailman/listinfo.cgi/mpiwg-rma
> 
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-- 
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
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