[ofa-general] Re: [PATCH RFC] RDMA/CMA: Allocate PS_TCP ports from the host TCP port space.

[Steve Wise]

Sean Hefty wrote:

> 
> Okay - for final patches, I think we want to remove the rdma_cm specific 
> port spaces, along with changing the API to clarify that it uses the 
> same port space as TCP/UDP.
> 

If we get rid of the rdma_cm specific port spaces, do we then reduce the 
  valid possible spaces to just TCP and UDP?  Or what?  In the sockets 
paradigm, the socket is explicitly bound to a protocol space when its 
created (based on the protocol id).  Do you think we need to change the 
rdma_cm_id to have such a concept?  IE when you create the cm_id, you 
say your intended QP type or port space?  The current API lends itself 
to somone incorrectly choosing a port space, by the way.

But should we really change the API that drastically?  Or just keep the 
port spaces and make PS_TCP share the host's port space.

The only applications that really need this port space are apps that run 
on iWARP only or want to support both iWARP and IB via the 
transport-independent verbs and rdma-cm.  So things like IPoIB probably 
shouldn't use or need the TCP port space.

Maybe the rdma-cm port spaces should really be IB, IWARP, or BOTH.  IB 
has its own port space, and IWARP or BOTH gets the TCP port space.

thoughts?

Steve.