Re: [19.11][20.11][21.11] ppc64 fixes backport

[Thomas Monjalon <thomas@monjalon.net>]

07/07/2022 09:44, Christian Ehrhardt:
> On Thu, Jul 7, 2022 at 8:51 AM Thomas Monjalon <thomas@monjalon.net> wrote:
> >
> > 06/07/2022 20:53, Luca Boccassi:
> > > On Wed, 29 Jun 2022 at 14:40, Xueming(Steven) Li <xuemingl@nvidia.com> wrote:
> > > >
> > > > Hi LTS maintainers,
> > > >
> > > > Confirmed with Thomas, mlx5 PMD needs the following patches to compile with the upstream rdma-core lib.
> > > >
> > > > 2022-05-25 2022-06-01 b251bb7630  eal/ppc: undefine AltiVec keyword vector      @Thomas Monjalon
> > > > 2022-05-03 2022-05-25 64fcadeac0  avoid AltiVec keyword vector  @Thomas Monjalon
> > > >
> > > > I tried to backport to 20.11.6 LTS, cherry-pick works without conflicts.
> > > >
> > > > Best Regards,
> > > > Xueming Li
> > >
> > > Hi,
> > >
> > > This patch:
> > >
> > > 2022-05-25 2022-06-01 b251bb7630  eal/ppc: undefine AltiVec keyword
> > > vector      @Thomas Monjalon
> > >
> > > Looks like an incompatible change? Commit message says so too:
> > >
> > > "This is a compatibility breakage for applications which were using
> > > the keyword "vector" for its AltiVec meaning."
> > >
> > > The first one looks like but I don't think we should pick up the
> > > second one for the LTS branches?
> >
> > Yes if we undefine "vector", we break applications using this syntax.
> > That's a required change for recent rdma-core which uses the name "vector"
> > for another purpose.
> > I don't know what is best/worst.
> 
> It is ok for new DPDK releases to add this, but not for LTS backports.
> 
> In general LTS releases are usually updated and rebuild against their
> own older environment.
> So if "new rdma-core" is a problem it only is a  problem for "new DPDK".
> 
> IMHO LTS versions of DPDK should not take such a change.

OK