[Mpi-forum] Communicator info arguments

Pavan Balaji balaji at mcs.anl.gov
Fri Dec 7 16:13:56 CST 2012


Right.  I'm trying to understand what the intention was.

The intention stated at the Forum might not be accurate.

Either way, it needs to be stated in the standard, what the application
should expect.

 -- Pavan

On 12/07/2012 04:11 PM US Central Time, Jeff Hammond wrote:
> Okay, sorry, I didn't understand your question properly.
> 
> I think your example of intercomm_merge indicates that propagating
> info with functions other than dup is problematic and probably not
> easily specified.  The safest thing to do is to say that they do not
> propagate.
> 
> Jeff
> 
> On Fri, Dec 7, 2012 at 4:04 PM, Pavan Balaji <balaji at mcs.anl.gov> wrote:
>>
>> My question was for the other communicator creation functions.
>> Specifically, Comm_split in my query below.
>>
>>  -- Pavan
>>
>> On 12/07/2012 04:01 PM US Central Time, Jeff Hammond wrote:
>>> >From MPI-3 6.4.2 (MPI_COMM_DUP):
>>>
>>> "MPI_COMM_DUP duplicates the existing communicator comm with the
>>> associated key values, topology information and info hints."
>>>
>>> "MPI_COMM_DUP_WITH_INFO behaves exactly as MPI_COMM_DUP except that
>>> the info hints associated with the communicator comm are not
>>> duplicated in newcomm.  The hints provided by the arguments info are
>>> associated with the output communicator newcomm instead."
>>>
>>> Jeff
>>>
>>> On Fri, Dec 7, 2012 at 3:56 PM, Pavan Balaji <balaji at mcs.anl.gov> wrote:
>>>>
>>>> Apologies if this query needs to go a specific working group.  I wasn't
>>>> sure which one, so I'm sending it to the overall mailing list.
>>>>
>>>> If a communicator is created using MPI_COMM_DUP_WITH_INFO, is the info
>>>> argument "sticky" to all child communicators?  That is, if I split the
>>>> output communicator further, will the info argument propagate?
>>>>
>>>> Adam said that it would, at the Forum, but that doesn't seem accurate,
>>>> since that'll get weird if I do an Intercomm_merge with two
>>>> communicators, one of which has an info argument and the second does not.
>>>>
>>>> I couldn't find text saying one way or another in the document.
>>>>
>>>>  -- Pavan
>>>>
>>>> --
>>>> Pavan Balaji
>>>> http://www.mcs.anl.gov/~balaji
>>>> _______________________________________________
>>>> mpi-forum mailing list
>>>> mpi-forum at lists.mpi-forum.org
>>>> http://lists.mpi-forum.org/mailman/listinfo.cgi/mpi-forum
>>>
>>>
>>>
>>
>> --
>> Pavan Balaji
>> http://www.mcs.anl.gov/~balaji
> 
> 
> 

-- 
Pavan Balaji
http://www.mcs.anl.gov/~balaji



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