Re: [dpdk-dev] [PATCH v3 5/6] doc: remove dpdk iova aware notice

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

On Wed, Oct 25, 2017 at 12:01:26PM +0200, Thomas Monjalon wrote:
> 25/10/2017 11:50, Richardson, Bruce:
> > 
> > > -----Original Message-----
> > > From: dev [mailto:dev-bounces@dpdk.org] On Behalf Of Thomas Monjalon
> > > Sent: Wednesday, October 25, 2017 10:46 AM
> > > To: santosh <santosh.shukla@caviumnetworks.com>
> > > Cc: dev@dpdk.org; olivier.matz@6wind.com; jerin.jacob@caviumnetworks.com;
> > > hemant.agrawal@nxp.com; Burakov, Anatoly <anatoly.burakov@intel.com>
> > > Subject: Re: [dpdk-dev] [PATCH v3 5/6] doc: remove dpdk iova aware notice
> > > 
> > > Hi Santosh,
> > > 
> > > 24/10/2017 07:06, santosh:
> > > > Hi Thomas,
> > > >
> > > >
> > > > On Tuesday 24 October 2017 01:59 AM, Thomas Monjalon wrote:
> > > > > 20/10/2017 14:31, Santosh Shukla:
> > > > >> Removed dpdk iova aware ABI deprecation notice, and updated ABI
> > > > >> change details in release_17.11.rst.
> > > > >>
> > > > >> Signed-off-by: Santosh Shukla <santosh.shukla@caviumnetworks.com>
> > > > >> Acked-by: John McNamara <john.mcnamara@intel.com>
> > > > >> ---
> > > > >> --- a/doc/guides/rel_notes/deprecation.rst
> > > > >> +++ b/doc/guides/rel_notes/deprecation.rst
> > > > >> -* eal: An ABI change is planned for 17.11 to make DPDK aware of
> > > > >> IOVA address
> > > > >> -  translation scheme.
> > > > >> -  Reference to phys address in EAL data-structure or functions may
> > > > >> change to
> > > > >> -  IOVA address or more appropriate name.
> > > > >> -  The change will be only for the name.
> > > > >> -  Functional aspects of the API or data-structure will remain same.
> > > > > Sorry, this series cannot be applied as is because it is breaking
> > > > > more than EAL API. The API of mbuf and mempool are also changed.
> > > > > We need to choose one of these three options:
> > > > > 	1/ accept to break all API in 17.11
> > > > > 	2/ postpone the whole series to 18.02
> > > >
> > > > Theme of series is to make dpdk iova aware so I would prefer option 1)
> > > or 2).
> > > > However I have no strong opinion on this topic.
> > > > Lets get more opinion from others about option 1/2/3.
> > > >
> > > > > 	3/ rename only EAL API in 17.11 and postpone mbuf/mempool
> > > 
> > > After discussing with Olivier it appeared there is a fourth solution.
> > > We should not break any API (EAL, mbuf, mempool).
> > > 
> > > I would like to merge these changes in RC2, but keeping compatibility with
> > > old names:
> > > - When you rename a function or a type, you can define a macro for the old
> > > name, alias the new name.
> > 
> > Note: using a macro doesn't prevent the ABI being broken if you rename a public function. You'll need to use function versioning too.
> 
> True
> We can use an inline function to avoid ABI breakage.

Nope, inline function won't work either, since that ends up the same as
the macro and compiled into the end app, not the library ABI. You
need a public non-inline wrapper function to keep ABI, or else function
renaming via symbol versioning/mapping.