Re: [PATCH v6 1/2] mbuf: support attaching external buffer to mbuf

[Thomas Monjalon <thomas@monjalon.net>]

26/04/2018 22:07, Olivier Matz:
> On Thu, Apr 26, 2018 at 09:58:00PM +0200, Thomas Monjalon wrote:
> > 26/04/2018 21:42, Olivier Matz:
> > > On Thu, Apr 26, 2018 at 06:10:36PM +0200, Thomas Monjalon wrote:
> > > > 26/04/2018 18:05, Andrew Rybchenko:
> > > > > On 04/26/2018 04:10 AM, Yongseok Koh wrote:
> > > > > > -#define RTE_MBUF_INDIRECT(mb)   ((mb)->ol_flags & IND_ATTACHED_MBUF)
> > > > > > +#define RTE_MBUF_INDIRECT(mb)   RTE_MBUF_CLONED(mb)
> > > > > 
> > > > > We have discussed that it would be good to deprecate RTE_MBUF_INDIRECT()
> > > > > since it is not !RTE_MBUF_DIREC(). Is it lost here or intentional (may 
> > > > > be I've lost
> > > > > in the thread)?
> > > > 
> > > > I think it should be a separate deprecation notice.
> > > 
> > > Agree with Andrew that RTE_MBUF_INDIRECT should be deprecated
> > > to avoid confusion with !DIRECT.
> > 
> > What do you mean?
> > We should add a comment? Or poisoining the macro? Or something else?
> > Should it be removed? In which release?
> 
> Sorry if I was not clear.
> 
> Not necessarly remove the macro for this release. But I think we
> should announce it and remove it, following the process.
> 
> I suggest:
> - for 18.05: send the deprecation notice + add a comment in the .h
>   saying that the macro will be deprecated in 18.08 (or 18.11, there
>   is no hurry if there is the comment)
> - for 18.08 (or 18.11): remove the macro (I don't think poisoining
>   is useful in this case).

OK it works for me.
I think we can wait 18.11 for a complete removal, except if the mbuf API
is broken in 18.08 and not 18.11. But we probably need to do a soft 18.08
release without any breakage at all.

So, Yongseok, please prepare a patch including a deprecation notice
with a fuzzy removal deadline, and a doxygen comment.
As it requires a special process (3 acks, etc), it is better to have it
as a separate patch.

Thanks