Fwd: Re: [openib-general] static LID computation withTS_HOST_DRIVER

[Roland Dreier]

    Yaron> A better solution that IBTA needs to look at is creating a
    Yaron> well known Loopback LID value that apps use when they want
    Yaron> to talk locally (like IP 127...)

If/when IBTA specifies this and available hardware implements this,
then this will be a great solution.

In the meantime, I don't see a problem with having a mechanism to
provide an initial value for PortInfo:LID _before_ the SM discovers
the node.  The SM must be able to deal with arbitrary values of this
field, since it can't make any assumptions about the state of the
subnet.  I don't think the spec forbids having a mechanism to specify
the initial value of PortInfo:LID.

I agree that the spec places the SM under no obligation to preserve
the LIDs it finds.  However, if someone wants to run an application
that requires loopback connections to be preserve, I see no problem
with requiring an SM that provides an administrative mechanism for
static LID assignment.

The advantage of this scheme is that it requires no modifications to
either the IB spec or existing IB hardware.

Thanks,
  Roland