[ovs-dev] [PATCH] ofproto-dpif: Init ukey->dump_seq to zero

[Ben Pfaff]

On Fri, Apr 06, 2018 at 10:44:13AM -0700, Ben Pfaff wrote:
> [also CCing Joe on the chance that he wants to comment]
> 
> On Fri, Apr 06, 2018 at 09:34:38AM +0000, Jan Scheurich wrote:
> > > -----Original Message-----
> > > From: Ben Pfaff [mailto:blp at ovn.org]
> > > Sent: Wednesday, 04 April, 2018 22:28
> > > 
> > > Oh, that's weird.  It's as if I didn't read the patch.  Maybe I just
> > > read some preliminary version in another thread.
> > > 
> > > Anyway, you're totally right.  I applied this to master.  If you're
> > > seeing problems in another branch, let me know and I will backport.
> > 
> > Thanks!
> > 
> > I think the issue was introduced into OVS by the following commit a long time ago. 
> > 
> > commit 23597df052262dec961fd86eb7c54d10984a1ec0
> > Author: Joe Stringer <joestringer at nicira.com>
> > Date:   Fri Jul 25 13:54:24 2014 +1200
> > 
> > It's a temporary glitch that can cause unexpected behavior only within
> > the first few hundred milliseconds after datapath flow creation. It is
> > most likely to affect "reactive" controller use cases (MAC learning,
> > ARP handling), like the OVN test case that now failed with a small
> > change of timing. So it is possible that one could notice short packet
> > drops or duplicate PACKET_INs in real SDN deployments when looking
> > close enough.
> > 
> > My preference would be to backport it all the way to OVS 2.5. But of
> > course I don't have proof that there are actual problems out in the
> > field that it would solve.
> 
> OK.
> 
> I am going to sit on this for a few days and see whether anyone reports
> unusual issues.  If nothing arises, I'll backport as far as reasonable.

I backported to branch-2.9 and branch-2.8.