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

[Christian Ehrhardt <christian.ehrhardt@canonical.com>]

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.


>


-- 
Christian Ehrhardt
Senior Staff Engineer, Ubuntu Server
Canonical Ltd