Re: [dpdk-dev] [dpdk-techboard] [RFC] Proposals and notes from ABI stability panel @ DPDK Userspace

[Bruce Richardson <bruce.richardson@intel.com>]

On Wed, Sep 25, 2019 at 03:29:16PM +0100, Ray Kinsella wrote:
> 
> > In the short term, based on the feedback at the conference and to give
> > something concrete to be considered, here is a suggestion,
> > 
> > ABI freeze starts at 20.02 for 9 months, with a review as planned to see
> > if 20.11 should be frozen 2 years.
> > 
> > pros:
> > + Eliminates any need for delaying 19.11 release
> > 
> > + Allows maintainers to stick to current deprecation policy if they need
> > to make changes prior to freeze (Based on comment from Hemmant)
> > 
> > + Not sure if it's worthy of a new bullet or clear from above but I
> > would add that changing the release cycle/deprecation policy etc 2 weeks
> > (I think) before RC1 is late to say the least and there is no notice to
> > users
> > 
> > + Means that any changes required prior to freeze are not rushed with
> > usual big LTS release (19.11). Gives more time and maybe during a saner
> > release cycle (20.02)
> > 
> > cons:
> > - With view for possible 20.11 freeze, gives 2 releases to tease out
> > process instead of 3
> > 
> > - Perhaps it is desirable for some users to have the 19.11 LTS ABI
> > compatible with 20.02/05/08 releases
> > 
> > I've tried to keep them objective, of course people will have different
> > opinions about starting a freeze now vs. later etc. too.
> > 
> > thanks,
> > Kevin.
> > 
> 
> *interesting*
> 
> Another approach, possibly better approach, is to see the LTS as the
> final act following an ABI declaration/freeze.
> 
> We we declare the v20 ABI in DPDK 20.02, and hold that ABI until 21.02
> including the v20.11 LTS. The LTS then becomes the cumulation of the ABI
> freeze.
> 
> I didn't go this road, because of the community habit of pushing things
> in just before the LTS, I thought it would be a bridge too far, and that
> it would get considerable push back.

I actually think this approach was initially rejected as having an ABI
break immediately after an LTS makes backporting fixes to the LTS more
problematic.

/Bruce