[ovs-dev] [PATCH 15/18] dpif-xlate: Add functions to update multicast snooping db

Flavio Leitner fbl at redhat.com
Sat May 24 00:59:09 UTC 2014


On Tue, May 20, 2014 at 03:55:50PM -0700, Ben Pfaff wrote:
> On Tue, May 20, 2014 at 03:53:26PM -0700, Ben Pfaff wrote:
> > I suspect that unconditionally taking the write-lock in
> > update_mcast_snooping_table() is going to serialize flow translation,
> > in practice.  That's why update_learning_table() checks whether any
> > change is needed under the read-lock first, then grabs the write-lock
> > if it's really needed.  But in the long run RCU is better (and we
> > should probably adapt mac-learning to use it, or we could switch to a
> > fatlock there as an easy first step).
> 
> Looking at the next patch, I guess it only matters for multicast
> packets.  Maybe not worth bothering.

The problem is that if someone configures a port to be flooded
while that is running, we could have duplicated packets (normal
action + flood port).

Yes, it's specific for multicast packets and I have an idea to
improve this for v2.

Flavio



More information about the dev mailing list