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

Jan Scheurich jan.scheurich at ericsson.com
Wed Apr 4 19:03:43 UTC 2018

Thanks Ben,

I hope what my patch does is precisely what you suggest. I had the same thoughts when I had a closer look at the code.

Regards, Jan

> -----Original Message-----
> From: Ben Pfaff [mailto:blp at ovn.org]
> Sent: Wednesday, 04 April, 2018 19:20
> To: Jan Scheurich <jan.scheurich at ericsson.com>
> Cc: dev at openvswitch.org; Zoltán Balogh <zoltan.balogh at ericsson.com>; jpettit at ovn.org
> Subject: Re: [PATCH] ofproto-dpif: Init ukey->dump_seq to zero
> On Wed, Apr 04, 2018 at 01:26:02PM +0200, Jan Scheurich wrote:
> > In the current implementation the dump_seq of a new datapath flow ukey
> > is set to seq_read(udpif->dump_seq). This implies that any revalidation
> > during the current dump_seq period (up to 500 ms) is skipped.
> >
> > This can trigger incorrect behavior, for example when the the creation of
> > datapath flow triggers a PACKET_IN to the controller, which which course
> > the controller installs a new flow entry that should invalidate the
> > original datapath flow.
> >
> > Initializing ukey->dump_seq to zero implies that the first dump of the
> > flow, be it for revalidation or dumping statistics, will always be
> > executed as zero is not a valid value of the ovs_seq.
> >
> > Signed-off-by: Jan Scheurich <jan.scheurich at ericsson.com>
> If we are going to do this, then we should delete the 'dump_seq' member
> of struct upcall, because it will always be zero.  It is also worth
> considering whether the other caller of ukey_create__() should pass 0,
> and if so then we can delete the 'dump_seq' parameter of
> ukey_create__().
> Thanks,
> Ben.

More information about the dev mailing list