[openib-general] ipoib mcast questions...

[Roland Dreier]

 > 1) the set_multicast_list net device callback
 > seems to just kick off another thread to do
 > the work of registering the multicast group.
 > the mc_list net_device field is only valid
 > under the netif_tx_lock, but this lock is not
 > grabbed by the restart_task.  what happens
 > if the mc_list is modified while in the
 > restart_task?

Just looking quickly, I see that ipoib_mcast_restart_task() does
netif_tx_lock() (right near the top).  Isn't this sufficient?

 > 2) there seem to be 2 threads, the restart_task
 > which creates queries and the join_task which sends
 > off the mad requests.  why?  is there some performance
 > advantage?  it would seem easier to do the registrations
 > serially in the restart task...

I guess it's really that way mainly for historical reasons.  I'd be
glad to see patches that simplify things (of course making sure that
everything still works ;)

 - R.