[openib-general] [RFC] [PATCH 2/7] ib_multicast 2.6.20: add ib_multicast module to track join requests from the same port

[Roland Dreier]

    Michael> Why is this even a good idea?  If you are looking for
    Michael> reasons using mutlicast module in ipoib is good, I would
    Michael> say blocking unpriviledged userspace from joining IPoIB
    Michael> GID and snoopig on all mcast traffic sounds like a better
    Michael> idea.  BTW, Sean, I think this is something we need for
    Michael> the ucma multicast part to go in. I would imagine kernel
    Michael> components could set some kind of flag on mcast join to
    Michael> make them exclusive.  API currently does not allow for
    Michael> that.

I don't think this is a real concern.  Already userspace can just
attach a QP to any MGID it wants -- how does it hurt to let it join an
arbitry MGID?

    Michael> And why the rush? Is the new module used at all yet?
    Michael> Let's see it get some use before switching a basic
    Michael> component over.

Yes, I would like to see another consumer, just to get a sanity check
that you have implemented the right thing.

    Michael> Finally, the patch in question also seems to introduce
    Michael> more cleanups and such. It would be less controversial if
    Michael> it was just an API change.

Agree -- please do cleanups as separate patches, preferably earlier in
the series (so that it's easier to back out the real change for
testing)

 - R.