Re: [dpdk-dev] [PATCH] pipeline: remove experimental tag from API

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

On Wed, Oct 13, 2021 at 11:02:02AM +0100, Kinsella, Ray wrote:
> 
> 
> On 13/10/2021 10:49, Thomas Monjalon wrote:
> > 13/10/2021 11:43, Kinsella, Ray:
> >> On 13/10/2021 10:40, Thomas Monjalon wrote:
> >>> 13/10/2021 10:51, Kinsella, Ray:
> >>>> On 12/10/2021 22:52, Thomas Monjalon wrote:
> >>>>> 12/10/2021 22:34, Dumitrescu, Cristian:
> >>>>>> From: Thomas Monjalon <thomas@monjalon.net>
> >>>>>>> 01/09/2021 14:20, Jasvinder Singh:
> >>>>>>>> These APIs were introduced in 18.05, therefore removing
> >>>>>>>> experimental tag to promote them to stable state.
> >>>>>>>>
> >>>>>>>> Signed-off-by: Jasvinder Singh <jasvinder.singh@intel.com>
> >>>>>>>> ---
> >>>>>>>>  lib/pipeline/rte_port_in_action.h | 10 ----------
> >>>>>>>>  lib/pipeline/rte_table_action.h   | 18 ------------------
> >>>>>>>>  lib/pipeline/version.map          | 16 ++++++----------
> >>>>>>>>  3 files changed, 6 insertions(+), 38 deletions(-)
> >>>>>>>
> >>>>>>> Cristian, please can you check whether you intend to keep these functions in
> >>>>>>> future?
> >>>>>>> If they are candidate to be removed, there is no point to promote them.
> >>>>>>
> >>>>>> Hi Thomas,
> >>>>>>
> >>>>>> Yes, they are candidate for removal, as the new rte_swx_pipeline API evolves.
> >>>>>>
> >>>>>> But removing them requires updating the drivers/net/softnic code to use the new API, which is not going to be completed in time for release 21.11.
> >>>>>>
> >>>>>> So given this lag, it might be better to simply promote these functions to stable API now, as Ray suggests, instead of continuing to keep them experimental; then, once these functions are no longer used, then we can remove them, most likely in 22.11.
> >>>>>>
> >>>>>> So I will ack these patches, but I am willing to reconsider if you feel strongly against this approach.
> >>>>>
> >>>>> I think we should not promote API that we know will disappear soon.
> >>>>> The stable status means something for the users.
> >>>>> Ray, what is your opinion?
> >>>>>
> >>>>
> >>>> Well - I agree with Cristian (he and I discuss this a few weeks ago).
> >>>> My position is if you are going to maintain an API, that means giving a few guarantees.
> >>>> The API's have been experimental for 3 years ... at what point do they mature?
> >>>>
> >>>> However, I agree there is two ways to look at this thing, I try to be pragmatic. 
> >>>> Maturing of any ABI/API is a conversation between a maintainer and the contributor.
> >>>> If they strongly feel, it is a pointless exercise - I won't argue. 
> >>>
> >>> I think you did't get it.
> >>> This API will be removed soon.
> >>> That's why I think it doesn't make sense to make them stable, just before removing.
> >>>
> >>
> >> Nope, I got it 110%
> >> I reflected both my opinion as ABI Maintainer, and tried to be pragmatic about the situation.
> >>
> >> As I said "Maturing of any ABI/API is a conversation between a maintainer and the contributor.
> >> If they strongly feel, it is a pointless exercise - I won't argue."
> > 
> > Sorry, I don't understand your position.
> > Do you think we should promote functions to stable which are candidate to be removed soon?
> > 
> 
> I am just reflecting the policy here.
> 
> "An API’s experimental status should be reviewed annually, by both the maintainer and/or the original contributor. Ordinarily APIs marked as experimental will be promoted to the stable ABI once a maintainer has become satisfied that the API is mature and is unlikely to change."
>
If an API is planned for removal, then I think it falls under the bucket of
"likely to change", so should not be made non-experimental. Therefore I'd
agree with Thomas view on this - not so much that promoting them is
pointless, but I'd actually view it as harmful in encouraging use that will
be broken in future.

/Bruce