Just want to make this very clear, since other LANL people are on this
list.
I am in no way saying that LANL users are ill-intentioned or
deliberately attempting to circumvent system restrictions. See my
other note for the most common scenarios that lead to this problem and
you will see that is the case.
I do not believe this will fully achieve the goal you seek as it has
been attempted before - it helped, but doesn't fully succeed.
That said, I do not oppose implementing it as it -does- help alleviate
the problem.
Please also note that - if you are worried about problems caused when
tuning - it is often the case that combinations of param values cause
trouble as opposed to the value of a single param (e.g., when
specifying QP buffer sizes). I'm not sure how your proposal will deal
with that situation, but I leave that to you. :-)
On Sep 4, 2009, at 7:58 AM, Arthur Huillet wrote:
Hi,
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.
--
Greetings, A. Huillet
_______________________________________________
devel mailing list
de...@open-mpi.org
http://www.open-mpi.org/mailman/listinfo.cgi/devel
