[OMPI devel] Multi-rail on openib

[Mouhamed Gueye]

Hi all,

I am working on  multi-rail IB and I was wondering how connections are 
established between ports.  I have two hosts, each with 2 ports on a 
same IB card, connected to the same switch.

My question is : how ports are connected between them ? Is there a queue 
pair between all ports or only between ports of the same number (for 
example, Host A => port 1 <===> port 1 <= Host B and Host A => port 2 
<===> port 2 <= Host B or maybe Host A => port 1 <===> port 2 <= Host B 
and Host A => port 2 <===> port 1 <= Host B) ? Is it possible to force 
the connection scheme on the openib btl ?

Thanks

Mouhamed