DPDK compilers and RHEL 7 support

["Morten Brørup" <mb@smartsharesystems.com>]

+ Red Hat tech board members

> From: Stephen Hemminger [mailto:stephen@networkplumber.org]
> Sent: Wednesday, 26 March 2025 20.21
> 
> On Wed, 26 Mar 2025 19:06:58 +0100
> Morten Brørup <mb@smartsharesystems.com> wrote:
> 
> > > From: Bruce Richardson [mailto:bruce.richardson@intel.com]
> > > Sent: Wednesday, 26 March 2025 17.22
> > >
> > > On Tue, Mar 25, 2025 at 05:22:15PM +0000, Bruce Richardson wrote:
> > > > When doing a build for a target that already has the instruction
> sets
> > > > for AVX2/AVX512 enabled, skip emitting the AVX compiler flags, or
> the
> > > > skylake-avx512 '-march' flags, as they are unnecessary. Instead,
> when
> > > > the default flags produce the desired output, just use them
> > > unmodified.
> > > >
> > > > Depends-on: series-34915 ("remove component-specific logic for
> AVX
> > > builds")
> > > >
> > > > Signed-off-by: Bruce Richardson <bruce.richardson@intel.com>
> > > > ---
> > > >
> > > > This patchset depends on the previous AVX rework. However,
> sending it
> > > > separately as a new RFC because it effectively increases the
> minimum
> > > > compiler versions needed for x86 builds - from GCC 5 to 6, and
> > > > Clang 3.6 to 3.9.
> > > >
> > > > For now, I've just documented that as an additional note in the
> GSG
> > > that
> > > > these versions are recommended, but it would be simpler if we
> could
> > > just
> > > > set them as the required minimum baseline (at least in the docs).
> > > >
> > > > Feedback on these compiler version requirements welcome.
> > > >
> > >
> > > +techboard
> > >
> > > Ping for a little bit of feedback for this. Are we ok to bump the
> > > minimum
> > > compiler versions as described above, or will I continue with the
> > > approach
> > > in this RFC of keeping the minimum and just recommending the higher
> > > versions for x86 platforms?
> > >
> > > For reference GCC 6.1 was released April 2016[1], and, Clang 3.9
> was
> > > released Sept 2016[2]
> > >
> > > /Bruce
> > >
> > > [1] https://gcc.gnu.org/gcc-6/
> > > [2] https://releases.llvm.org/
> >
> > Considering GCC versions shipped with RHEL [3]...
> > We kind of support RHEL 7, but we already require a newer compiler
> (GCC 5) than shipped with RHEL 7 (GCC 4.8).
> > RHEL 8 ships with GCC 8, which was released in May 2018 [4]. Maybe we
> can jump to GCC 8?
> >
> > BTW, we should also apply the same principle I argued [5] should
> apply for upgrading the Kernel requirements: There should be a need for
> specific feature or similar - which there is with your patch - and the
> details should be mentioned in the release notes.
> >
> > [3]: https://access.redhat.com/solutions/19458
> > [4]: https://gcc.gnu.org/gcc-8/
> > [5]:
> https://inbox.dpdk.org/dev/CAMEVEZutf4sJ=EQFONw_bJW0tGTWqTbF_Tk_y38qzBL
> ccco46Q@mail.gmail.com/T/#me7c8f1dbe4331ccf232d43512d6ddb51458c568a
> >
> 
> RHEL 7 reached end of life on June 30, 2024.
> DPDK need no longer support it on future versions.

CentOS 7 reached EOL June 2024, yes.
RHEL 7 reached End of Maintenance June 2024, but RHEL 7 Extended Life Cycle Support is available until June 2028 [6].

Although RHEL 7 not fully EOL, I would consider "End Of Maintenance" sufficiently dead for future DPDK versions not needing to support it.
If you are running a production system on a distro that's on Extended Life Cycle Support, you shouldn't deploy a new DPDK version - and if you do anyway, it's your own problem, not the DPDK community's problem.
@Aaron, @Kevin, @Maxime - speak up if you disagree!


[6]: https://www.redhat.com/en/technologies/linux-platforms/enterprise-linux/rhel-7-end-of-maintenance