[ofa-general] IPoIB kernel Oops -- race condition

[Yossi Etigin]

Jack Morgenstein wrote:
> I'm very worried that if we do things asymmetrically we will introduce instability.
> Regarding doing only the multicast leave/free in the workqueue -- I do not see how to do
> this cleanly (i.e., everything as is, but simply scheduling a leave-free task).
> 
> Yossi, Roland, Eli?
> 
> -Jack

I think we could put just the leave/free on the WQ. It would be symmetrical to join which
takes place on the WQ as well. We would probably need to add a "to-free" list to ipoib,
the opposite of the join list (multicast_list) which is currently there.
Instead of doing free to mcast, we list_add it to some priv->mcast_leave_list and queue
the work. I think it can be safe to defer multicast leave/free, as long as it's removed from
the mcast tree on time.

--Yossi