[ewg] user SA notifications, redux

[Hefty, Sean]

> As I mentioned earlier, the reason ib_sa acts as a single access point for
> SA/SM traps and notices is because traps and notices are sent to ports, not
> to
> queue pairs and not to processes. That means only one entity can be
> subscribed
> for notices and traps at any particular time, and must manage them,
> "sharing
> them out" among all processes that are interested in them.

Can you provide a brief description of the intended usage model?