[openib-general] multicast code/merge status

[Or Gerlitz]

On 1/10/07, Sean Hefty <mshefty at ichips.intel.com> wrote:
> > mmm, weird, are there active rdmacm multicast consumers involved in
> > this settings?
>
> I believe the issue is restricted to ipoib only.

What does it means in this context that ipoib attempts to join a non
exisiting group, does it mean that ipoib assumes that the sm would
create the group?


> > OK, got you at last (sorry but i have somehow ignored the call to
> > ib_addr_get_mgid() at the rdmacm code). So to achieve interop with
> > IPoIB all we need to do is remove the rdmacm signature bit and not to
> > over-write the rdmacm qkey on the the qkey of the ipoib ipv4 broadcast
> > group, are you ok with that?

> I believe this would achieve interop with ipoib.  However, overwriting the qkey
> may break any existing UD communication that the user may have.  I just need to
> think about this more, and see what we can come up with.

Basically, since there is only one QKEY per UD QP, a user IB UD app
should either set a qp per qkey or take the same approach as IPoIB
does, one qp, one qkey, all unicast/mcast traffic and mcast joins use
the same qkey, it sounds fine to me.

Or.