[ofa-general] [PATCH RFC] IB/ipoib: enable IGMP for userpsacemulticast IB apps

[Or Gerlitz]

Or Gerlitz wrote:
> The kernel IB stack allows (through the RDMA CM) user space multicast 
> applications to interoperate with IP based apps optionally running at a different
> IP subnet.

> To support this inter-op for the case where the receiving party resides at
> the IB side, there is a need to handle IGMP (reports/queries) else the local
> IP router would not forward this multicast traffic.

> This patch does a lookup on the database used for multicast reference counting
> and enhances IPoIB to ignore mulicast group which is already handled by 
> user space, all this under a per device policy flag.

> That is when the policy flag allows it, IPoIB will not join/attach its QP to a
> multicast group which has an entry on the database. The default value is "disallowed",
> where through /sys/class/net/$dev/umcast one can allow/disallow and read it.

Roland,

Any comment on the basic approach and the specific implementation?

Tziporet,

This patch is targeted to both upstream and OFED 1.3 (also technically 
it is against 2.6.23-rc5 so it fits both), however, I prefer to have it 
first accepted to upstream and then apply it to OFED.

With the OFED 1.3 feature freeze being next Monday, what do you say, is 
there a chance for for the feature freeze to move further (eg as of no 
release yet of libmlx4 and the OFED policy to include only released 
libraries)?

Or.