[ofa-general] Re: [ewg] Re: [OMPI devel] Re: OMPI over ofed udapl - bugs opened

[Michael S. Tsirkin]

> Quoting Jeff Squyres <jsquyres at cisco.com>:
> Subject: Re: [ewg] Re: [OMPI devel] Re: OMPI over ofed?udapl -?bugs?opened
> 
> On May 10, 2007, at 8:23 AM, Or Gerlitz wrote:
> 
> >A different approach which you might want to consider is to have at  
> >the btl level --two-- connections per <src,dst> ranks. so if A  
> >wants to send B it does so through the A --> B connection and if B  
> >wants to send A it does so through the B --> A connection. To some  
> >extent, this is the approach taken by IPoIB-CM (I am not enough  
> >into the RFC to understand the reasoning but i am quite sure this  
> >was the approach in the initial implementation). At first thought  
> >it mights seems not very elegant, but taking it into the details  
> >(projected on the ompi env) you might find it  even nice.
> 
> What is the advantage of this approach?

Current ipoib cm uses this approach to simplify the implementation.
Overhead seems insignificant.

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MST