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From: Maestas, Christopher Daniel (cdmaest_at_[hidden])
Date: 2006-11-29 11:16:50


Ralph,

I agree with what you stated in points 1-4. That is what we are looking
for.
I understand your point now about the non-MPI users too. :-)

Thanks,
-cdm

-----Original Message-----
From: users-bounces_at_[hidden] [mailto:users-bounces_at_[hidden]] On
Behalf Of Ralph Castain
Sent: Wednesday, November 29, 2006 8:01 AM
To: Open MPI Users
Subject: Re: [OMPI users] Pernode request

Hi Chris

Thanks for the patience and the clarification - much appreciated. In
fact, I have someone that needs to learn more about the code base, so I
think I will assign this to him. At the least, he will have to learn a
lot more about the mapper!

I have no problem with modifying the pernode behavior to deal with the
case of someone specifying -np as you describe. It would be relatively
easy to check. As I understand it, you want the behavior to be:

1. if no -np is specified, launch one proc/node across entire allocation

2. if -np n is specified AND n is less than the number of allocated
nodes, then launch one proc/node up to the specified number. Of course,
this is identical to just doing -np n -bynode, but that's immaterial.
;-)

3. if -np n is specified AND n is greater than the number of allocated
nodes, error message and exit

4. add a -npernode n option that launches n procs/node, subject to the
same tests above.

Can you confirm?

Finally, I think you misunderstood my comment about the MPI folks. Our
non-MPI users couldn't care less about commonality of command line
arguments across MPI implementations. Hence, I leave issues in that area
to the MPI members of the team - they are the ones that decide how to
deal with the myriad of different option syntaxes in the MPI community.

Gives me too much of a headache! :-)

Ralph