Re: [dpdk-stable] [dpdk-dev] 19.11.4 patches review and test

["Pai G, Sunil" <sunil.pai.g@intel.com>]

Hi Christian, Ilya

> -----Original Message-----
> From: Ilya Maximets <i.maximets@ovn.org>
> Sent: Thursday, March 18, 2021 8:18 PM
> To: Pai G, Sunil <sunil.pai.g@intel.com>; Christian Ehrhardt
> <christian.ehrhardt@canonical.com>; Stokes, Ian <ian.stokes@intel.com>;
> Ilya Maximets <i.maximets@ovn.org>; Govindharajan, Hariprasad
> <hariprasad.govindharajan@intel.com>
> Cc: Richardson, Bruce <bruce.richardson@intel.com>; Luca Boccassi
> <bluca@debian.org>; stable@dpdk.org; dev <dev@dpdk.org>; James Page
> <james.page@canonical.com>
> Subject: Re: [dpdk-dev] 19.11.4 patches review and test
> 
> On 3/18/21 2:36 PM, Pai G, Sunil wrote:
> > Hey Christian,
> >
> > <snipped>
> >
> >> back  in 19.11.4 these DPDK changes were not picked up as they have
> >> broken builds as discussed here.
> >> Later on the communication was that all this works fine now and
> >> thereby Luca has "reverted the reverts" in 19.11.6 [1].
> >>
> >> But today we were made aware that still no OVS 2.13 builds against a
> >> DPDK that has those changes.
> >> Not 2.13.1 as we have it in Ubuntu nor (if it needs some OVS changes
> >> backported) the recent 2.13.3 does build.
> >> They still fail with the very same issue I reported [2] back then.
> >>
> >> Unfortunately I have just released 19.11.7 so I can't revert them
> >> there - but OTOH reverting and counter reverting every other release
> >> seems wrong anyway.
> 
> It is wrong indeed, but the main question here is why these patches was
> backported to stable release in a first place?
> 
> Looking at these patches, they are not actual bug fixes but more like "nice to
> have" features that additionally breaks the way application links with DPDK.
> Stuff like that should not be acceptable to the stable release without a strong
> justification or, at least, testing with actual applications.
> 
> Since we already have a revert of revert, revert of revert of revert doesn't
> seem so bad.
> 
> >>
> >> I wanted to ask if there is a set of patches that OVS would need to
> >> backport to 2.13.x to make this work?
> >> If they could be identified and prepared Distros could use them on
> >> 2.13.3 asap and 2.13.4 could officially release them for OVS later on.
> >>
> >> But for that we'd need a hint which OVS changes that would need to be.
> >> All I know atm is from the testing reports on DPDK it seems that OVS
> >> 2.14.3 and 2.15 are happy with the new DPDK code.
> >
> >> Do you have pointers on what 2.13.3 would need to get backported to
> >> work again in regard to this build issue.
> >
> > You would need to use partial contents from patch :
> > http://patchwork.ozlabs.org/project/openvswitch/patch/1608142365-
> 26215
> > -1-git-send-email-ian.stokes@intel.com/
> >
> > If you'd like me to send patches which would work with 2.13, 2.14, I'm
> > ok with that too.[keeping only those parts from patch which fixes the issue
> you see.] But we must ensure it doesn’t cause problems for OVS too.
> > Your thoughts Ilya ?
> 
> We had more fixes on top of this particular patch and I'd like to not cherry-
> pick and re-check all of this again. 

I agree, we had more fixes on top of this. It would be risky to cherry-pick.
So it might be a better option to revert.


> For users stable releases should be
> transparent, i.e. should not have disruptive changes that will break their
> ability to build with version of a library that they would like to use.
> 
> What are exact changes we're talking about?  Will it still be possible to build
> OVS with older versions of a stable 19.11 if these changes applied?
> 
> >
> >
> >>
> >> [1]: http://git.dpdk.org/dpdk-stable/log/?h=19.11&ofs=550
> >> [2]: http://mails.dpdk.org/archives/stable/2020-September/024796.html
> > <snipped>
> >
> > Thanks and regards,
> > Sunil
> >