[openib-general] SA multicast patches

[Roland Dreier]

 > All multicast groups need to be tracked, which is why even groups with
 > MGID 0 are inserted into the tree.

OK...

 > Immediately above this code, the group is returned if ret == 0.

Right, I missed that.  But...

 > Calling mcast_find() for MGID 0 isn't useful, so the code avoids doing
 > this, but I think that it would work.  The caller would just get an
 > arbitrary group.

Now this is confusing -- you say the code avoids looking up MGID 0 in
the rbtree.  So why do you have to insert those groups in the tree and
have the allow_duplicates() flag etc?  If you're never going to look
up the group, I assume you have some other way of finding it and so
you don't actually have to insert MGID 0 groups after all... right?

Or is it that you want to be able to iterate through the whole rbtree
and get the MGID 0 groups too?

 - R.