Re: [PATCH v3 2/5] mbuf: add second dynamic field member for VA only build

[Thomas Monjalon <thomas@monjalon.net>]

28/09/2022 14:52, Olivier Matz:
> On Wed, Sep 28, 2022 at 09:24:51AM +0200, Thomas Monjalon wrote:
> > 21/09/2022 15:56, Shijith Thotton:
> > > mbuf physical address field is not used in builds which only uses VA. It
> > > is used to expand the dynamic field area.
> > > 
> > > Signed-off-by: Shijith Thotton <sthotton@marvell.com>
> > 
> > We cannot condition the use of the dynamic field.
> > I think it is enough justification to reject this patch.
> 
> I don't think it is an issue.
> 
> > And about adding a compilation option for IOVA in the first patch of this series,
> > I think it is not the direction the majority wants DPDK to go.
> > We tend to avoid compilation options.
> 
> In general, I agree that we don't want to have many custom compile-time options,
> especially if they impact ABI. It has several issues that have already been
> widely discussed.
> 
> However, in this specific case, we can suppose that removing buf_iova is a
> long-term goal (in years). Having this compile-time option is a way to test this
> approach, and progressively prepare the drivers to support it. Then, in few
> years (if we are still convinced), we may announce an abi breakage and switch to
> this new mode by default.

You convinced me.