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From: Brian Barrett (brbarret_at_[hidden])
Date: 2005-11-21 10:39:16


On Nov 21, 2005, at 10:34 AM, Troy Telford wrote:

> On Mon, 21 Nov 2005 06:00:05 -0700, Jeff Squyres <jsquyres_at_open-
> mpi.org>
> wrote:
>
>> These warnings will likely be removed (or, more specifically, only
>> displayed if requested) once we include the feature to display which
>> BTL components/networks are being used at run-time.
>
> While only really useful for testing, it would be neat to be able
> to say
> 'try to use every component execept this one.' For instance, should I
> feel the need to scratch the itch of using IP-over-IB or TCP over
> Myrinet
> -- in my case, this would mainly be because of my cluster's 10/100
> switch,
> and I'd like to test/tune either OMPI's TCP performance, or IPoIB/
> TCPoMyri
> driver performance. In such a case, I could say 'ignore mvapi; yes
> RDMA
> is good, sure it's a silly thing do do -- now bow to my will ye
> minions,
> and despair.'

I'm going to have to remember that one :).

> Naturally, I could do this by simply removing the openib, mvapi, gm,
> and/or mx components; but that would require typing more characters
> than
> '--ignore_mca btl gm'.

We actually have this feature already... You can either do:

   -mca btl_base_exclude mvapi

or

   -mca btl ^mvapi

They are essentially equivalent. The first will load the mvapi
component, but never schedule any fragments on it. The second will
just not load the mvapi component. Sometimes we actually anticipate
user requests - not often, but sometimes ;).

Brian

-- 
   Brian Barrett
   LAM/MPI developer and all around nice guy
   Have a LAM/MPI day: http://www.lam-mpi.org/