[openib-general] IPoIB CM

[Or Gerlitz]

Sean Hefty wrote:
> Would you expect that the use of this code would likely result in creating 
> all-to-all connections between all nodes?  In particular, I'm thinking about MPI 
> applications that use all-to-all connections.  I realize this is done at the 
> RDMA layer, but is there anything that would end up connecting all of the nodes 
> via iopib?

yes,

If the MPI uses TCP/UDP over the IPoIB subnet for its (i,j) 
communication for all ranks 1 < i < j < n then yes, an all-to-all 
connection establishment model or an actual call to mpi-all-to-all would 
result in IPoIB CM connecting all-to-all . If the MPI uses IB (eg 
through uDAPL or libibverbs/librdmacm they would connect all-to-all 
through the cma.

Or.