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Subject: [OMPI devel] coll sm ramifications
From: Jeff Squyres (jsquyres_at_[hidden])
Date: 2009-09-22 12:32:23


Someday soon, coll sm will be reliable. Really. :-)

One thing I noticed is that coll sm is "slow" in communicator
construction and destruction because it mmap's upon creation and
munmap's upon deletion. For most apps, this probably doesn't matter.
For apps that create bajillions of communicators, the effect can be
noticeable.

There's at least one way to alleviate this effect, but I don't have
time to implement this optimization. I wrote up a ticket with a few
more details:

     https://svn.open-mpi.org/trac/ompi/ticket/2027

-- 
Jeff Squyres
jsquyres_at_[hidden]