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Subject: Re: [OMPI users] Factor of 10 loss in performance with 1.3.x
From: Eugene Loh (Eugene.Loh_at_[hidden])
Date: 2009-04-07 11:00:39

Iain Bason wrote:

> There are a bunch changes in the shared memory module between 1.2.9
> and 1.3.1. One significant change is the introduction of the "sendi"
> internal interface. I believe George Bosilca did the initial
> implementation. This is just a wild guess, but maybe there is
> something about sendi that increases latency when using the shared
> memory module.

But the sm BTL doesn't expose its sendi function, which puts it in the
same camp as most BTLs.

And the slowdown doesn't seem to be observed by anyone other than Steve
and his colleague?