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Subject: Re: [OMPI devel] RFC - "system-wide-only" MCA parameters
From: Arthur Huillet (arthur.huillet_at_[hidden])
Date: 2009-09-04 09:58:57


Ralph Castain wrote:
> Let me point out the obvious since this has plagued us at LANL with
> regard to this concept. If a user wants to do something different, all
> they have to do is download and build their own copy of OMPI.
We are well aware of that. It is relatively easy for a user to
circumvent the limitation...
> My point here: this concept can help, but it should in no way be
> viewed as a solution to the problem you are trying to solve. It is at
> best a minor obstacle as we made it very simple for a user to
> circumvent such measures.
... however the problem we are trying to solve is that some users may
inadvertantly modify parameters that they should not, for example when
playing around with MCA parameters in order to "tune" their application.
System wide parameters make it possible to give a message to the user
saying he is not allowed to do what he tried to do, and this is a nice
to have feature.

We are defending the system against users who are not ill-intentioned,
but simply do not always know what they are doing when they change
parameters. System wide parameters do help in this area.

A. Huillet