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Subject: Re: [OMPI devel] New BTL parameter
From: Gleb Natapov (glebn_at_[hidden])
Date: 2007-12-12 15:18:14

On Wed, Dec 12, 2007 at 02:03:02PM -0500, Jeff Squyres wrote:
> On Dec 9, 2007, at 10:34 AM, Gleb Natapov wrote:
> > Currently BTL has parameter btl_min_send_size that is no longer used.
> > I want to change it to be btl_rndv_eager_limit. This new parameter
> > will
> > determine a size of a first fragment of rendezvous protocol. Now we
> > use
> > btl_eager_limit to set its size. btl_rndv_eager_limit will have to be
> > smaller or equal to btl_eager_limit. By default it will be equal to
> > btl_eager_limit so no behavior change will be observed if default is
> > used.
> Can you describe why it would be better to have the value less than
> the eager limit?
It is just one more knob to tune OB1 algorithm. I sometimes don't want
to send any data by copy in/out at all. This is not possible right now.
With this new param I will be able to control this.