[Mpi-forum] Communicator info arguments

[Pavan Balaji]

Aha, yes.  Sorry, I missed that earlier.

 -- Pavan

On 12/07/2012 04:33 PM US Central Time, Jeff Hammond wrote:
> In 6.4.4, I find this:
> 
> "Info hints are not propagated by MPI from one communicator to another
> except when the communicator is duplicated using MPI_COMM_DUP or
> MPI_COMM_IDUP. In this case, all hints associated with the original
> communicator are also applied to the duplicated communicator."
> 
> I think this resolves any ambiguity.
> 
> Jeff
> 
> On Fri, Dec 7, 2012 at 4:13 PM, Pavan Balaji <balaji at mcs.anl.gov> wrote:
>>
>> 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
> 
> 
> 

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