[openib-general] [PATCH] [CM] add private data comparison tomatch REQs with listens

[Caitlin Bestler]

Fab Tillier wrote:

> 
> To sum up, it is simpler to add the private data compare
> functionality to the IB CM than to add it to every client
> that wants it.  The changes required don't complicate the API
> significantly, certainly within the grasp of someone
> interfacing to verbs.  I know this from experience because
> I've done it before.
> 
>> Or conversely, if you truly think this is of general utility, why not
>> implement it in INETD as well?
> 
> I wasn't making the case that it has general utility, just
> that it has utility within the realm of IB connection
> management.  Someone else is welcome to expand the scope if
> they see fit, but that's not what I'm advocating.
> 

But if your justification is MPI Ranks then you have already
exceed the scope "IB connection management".

There is an *existing* solution on how the remote end
establishes multiple connections to the same service
but with different instances.

That solution has been around for a very long time,
literally decades. Needing to restructure your code
slightly to preserve an existing interface that has
been around that long does not seem inapropriate.

Are you claiming that there is something in the
definition of the protocol that *requires* IB to
handle this differently than other networks do?

The only IB specific issue that I can think of
is that IB actually can afford to waste Service
IDs more than IP can affor to waste TCP Ports.