[ovs-dev] OVS-DPDK public meeting

Jan Scheurich jan.scheurich at ericsson.com
Wed Jun 6 15:28:44 UTC 2018

> > I was planning to if the community agreed it was warranted.
> >
> > However the general feeling expressed at the past few community calls is
> > that the next move should be to DPDK 18.11 LTS and I tend to agree with
> > this.
> >
> > The main advantage of this is the DPDK LTS lifecycle provides bug fixes
> > for DPDK for 2 years from release. Moving to a non DPDK LTS becomes a pain
> > as critical bug fixes will not be backported on the DPDK side so are not
> > addressed in OVS with DPDK either, we've seen this with some of the CVE
> > fixes for vhost quite recently.
> >
> > 18.05 is also the largest DPDK release to date with a lot of code being
> > introduced in the later RC stages which IMO increases the risk rather than
> > the gain of moving to it.
> >
> > However I'm open to discussing if a move to 18.05 is warranted, are there
> > any critical features or usecases it enables that you had in mind?
> >
> There are always the two big groups of users.
> - Those that want max stability for a huge Production setup (which would
> follow the pick LTS argument)
> - And those that want/need the very latest HW support and features (which
> would always prefer the latest version)

I subscribe to that statement.

> I had no single critical feature in mind for 18.05, but especially your
> argument of "the largest DPDK release to date with a lot of code being
> introduced" makes it interesting for the second group.
> Actually I think there are also plenty of new devices which are not
> supported at all before 18.02/18.05.
> So far my DPDK upgrade policy was "the last DPDK available which has at
> least one point release AND works with OVS".
> If OpenVswitch really changed to only support to each DPDK LTS version,
> then I might have to follow that.
> I must admit I already had the same thought to only pick .11 stable
> versions, so I'm not totally opposed if that is the way it is preferred for
> Openvswitch.
> But if we can make this a toleration (saying it works with 17.11 AND newer
> 18.05) then this would be a great contrib to OVS and IMHO be warranted.
> If the latter would work it could be great to spot issues early on instead
> of having a super-big jump from 17.11 to 18.11 in one shot.
> But if you have to kill support fot 17.11 to let it work with 18.05, then
> better not.
> Interested what other opinions on this are.

In my eyes that would the only way to satisfy both user's needs: Keep default support for the associated DPDK LTS release and add optional support for bleeding edge DPDK versions. The downside of this is that it will likely clutter the OVS code with conditional compiler directives to handle the DPDK API/ABI incompatibilities. Plus, someone must also clean these up at a later stage when they are no longer needed.

Today, OVS developers that really need the latest DPDK typically fork/branch OVS locally and maintain their fork until OVS master switches to the required DPDK version. That model doesn't burden the community with the problem.

BR, Jan

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