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

[Or Gerlitz]

Michael S. Tsirkin wrote:
> Quoting r. Sean Hefty <sean.hefty at intel.com>:
>> Add an ib_multicast module to perform reference counting of multicast
>> join / leave requests.  Modify ib_ipoib to use the multicast module.
>> Signed-off-by: Sean Hefty <sean.hefty at intel.com>

> On the ipoib change - whya re we doing it at all?
> ib_ipoib does not actually need the multicast refcounting, does it?
> I would be worried about doing major changes in ipoib multicast code, at this
> point.

The ipoib change is a must to allow for user space consumers to 
join/leave groups whose MGID is "of IP multicast origin".

So one process can have its IP mulitcast traffic carried out by ipoib 
and another process can use librdmacm to join the same multicast group 
and attach a QP to the same MGID.

Or.