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Subject: Re: [OMPI users] Invalid info object in MPI_Comm_spawn_multiple
From: Ralph Castain (rhc_at_[hidden])
Date: 2009-08-18 10:48:49


BTW: I did see one issue in your program. In the program that isn't working,
you declare the various input arrays for MPI_Comm_spawn_multiple, but only
the manager rank=0 ever initializes them. Thus, the other manager ranks were
passing random garbage down to the function.

Even though only the root process looks at those params, it still shouldn't
be random garbage just from a programming standpoint. At the least, set them
to NULL or something.

On Tue, Aug 18, 2009 at 8:34 AM, Ralph Castain <rhc_at_[hidden]> wrote:

> By any chance did you have the flag on to check MPI parameters? I think we
> have a bug in there that might be causing what you saw, but it would only be
> active if you had requested that OMPI check parameters.
>
>
> Thanks
> Ralph
>
>
> 2009/8/18 Federico Golfrè Andreasi <federico.golfre_at_[hidden]>
>
>> That's is you've done: the worker program spawned and the two versions of
>> the manager that call the spawning.
>> I you find something wrong please let me know.
>>
>> Thank you,
>> Federico
>>
>>
>>
>> 2009/8/18 Ralph Castain <rhc_at_[hidden]>
>>
>> ????
>>>
>>> Only the root process needs to provide the info keys for spawning
>>> anything. If that isn't correct, then we have a bug.
>>>
>>> Could you send us a code snippet that shows what you were doing?
>>>
>>> Thanks
>>> Ralph
>>>
>>>
>>> 2009/8/18 Federico Golfrè Andreasi <federico.golfre_at_[hidden]>
>>>
>>> I think I've solved my problem:
>>>>
>>>> in the previous code the arguments of the MPI_Comm_spawn_multiple where
>>>> filled only by the "root" process not by all the process in the group. Now
>>>> all the ranks have all that information and the spawn is done correctly.
>>>> But I read on http://www.mpi-forum.org/docs/mpi21-report/node203.htmthat those information are significant only at root.
>>>> In any case now it works.
>>>>
>>>> Thanks,
>>>> Federico
>>>>
>>>>
>>>>
>>>> 2009/8/18 Jeff Squyres <jsquyres_at_[hidden]>
>>>>
>>>>> On Aug 18, 2009, at 5:12 AM, Federico Golfrè Andreasi wrote:
>>>>>
>>>>> In the info object I only set the "host" key (after creatig the object
>>>>>> with the MPI_Info_create).
>>>>>>
>>>>>> I've modified my code to leave out that request and created the array
>>>>>> of Info object as an array of MPI_INFO_NULL but the problem is still the
>>>>>> same.
>>>>>> The error is thrown only when running with more than one process.
>>>>>>
>>>>>> Do I send you a short program for testing it?
>>>>>>
>>>>>
>>>>>
>>>>> If you have a short program that can replicate the problem, yes, that
>>>>> would be great.
>>>>>
>>>>> --
>>>>> Jeff Squyres
>>>>> jsquyres_at_[hidden]
>>>>>
>>>>>
>>>>> _______________________________________________
>>>>> users mailing list
>>>>> users_at_[hidden]
>>>>> http://www.open-mpi.org/mailman/listinfo.cgi/users
>>>>>
>>>>
>>>>
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>>>>
>>>
>>>
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>>
>>
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