Re: [RFC PATCH 00/12] Add config-time dependency tracking

[Bruce Richardson <bruce.richardson@intel.com>]

On Fri, Oct 16, 2026 at 04:51:48PM +0200, David Marchand wrote:
> On Fri, 16 Oct 2026 at 16:44, Bruce Richardson
> <bruce.richardson@intel.com> wrote:
> >
> > On Fri, Oct 16, 2026 at 04:35:51PM +0200, David Marchand wrote:
> > > On Fri, 16 Oct 2026 at 13:00, Bruce Richardson
> > > <bruce.richardson@intel.com> wrote:
> > > >
> > > > Add configuration time dependency tracking for libs and drivers in DPDK,
> > > > so that when a user requests a driver, all dependent drivers also get
> > > > enabled. Similarly with libraries. What is not enabled in this RFC is
> > > > support for enabling libraries based on driver requests, or enabling
> > > > either libs or drivers based on the enable-apps config option. I've
> > > > omitted the former for now, because it would involve moving more logic
> > > > out of the lib/meson.build file and drivers/meson.build files into the
> > > > top-level one, something I'm a little hesitant to do for now. The
> > > > addition of apps only adds value once the cross-type dependency tracking
> > > > is enabled, since no app depends on any others.
> > > >
> > > > The first 5 patches in this series are cleanups and bug fixes. The
> > > > following patches then implement the dependency tracking. While I
> > > > investigated having meson parse each components meson.build file
> > > > initially, without actually building it, this failed to work due to
> > > > logic other than variable assignments in many drivers.
> > > >
> > > > Instead, python scripts are used to manage the dependency list. For
> > > > easier debug, and future introspection this dependency management is
> > > > split between two scripts - the first generates a dependency table file
> > > > which it writes to the build folder, allowing us to analyse this
> > > > post-build if so desired. The second script uses this file to actually
> > > > compute the necessary per-component dependencies.
> > > >
> > > > The final patch of the series is a major reduction in the number of
> > > > required components for doing DPDK builds. We completely remove the list
> > > > of required libraries, and assume that a minimal build should only
> > > > require enough libraries to build EAL. However, EAL does assume that we
> > > > have a few additional buses, for example, EAL args are present for pci
> > > > and vdev. Also, in order for mempools to work, we always need to have
> > > > the default mempool ring driver build. That means that our de-facto
> > > > minimal build target set is the set of components needed to build
> > > > "bus/pci,bus/vdev,mempool/ring" (which would include EAL in the output,
> > > > which is why we can remove any hard-coded library lists)
> > > >
> > > > Bruce Richardson (12):
> > > >   build: fix name of base library object
> > > >   build: fix ignoring requested driver when class is disabled
> > > >   build: prevent overlap of enable and disable lists
> > > >   build: add direct support for optional dependencies
> > > >   net/bond: rename directory for consistency
> > > >   build: add script to generate dependencies list
> > > >   build: use recursive addition for enabled libraries option
> > > >   build: use recursive addition for enabled drivers option
> > > >   build: improve error reporting for unbuildable components
> > > >   build: add EAL common directory to global include list
> > > >   build: make EAL an explicit dependency
> > > >   build: simplify mandatory library lists
> > > >
> > > >  MAINTAINERS                                   |   2 +-
> > > >  app/meson.build                               |  15 +-
> > > >  app/proc-info/meson.build                     |   4 +-
> > > >  app/test-bbdev/meson.build                    |  18 +-
> > > >  app/test-crypto-perf/meson.build              |   4 +-
> > > >  app/test-pmd/meson.build                      |  50 ++---
> > > >  app/test/meson.build                          |   6 -
> > > >  buildtools/get-deps.py                        | 203 ++++++++++++++++++
> > > >  buildtools/meson.build                        |   2 +
> > > >  buildtools/resolve-deps.py                    |  80 +++++++
> > > >  devtools/test-meson-builds.sh                 |   3 +-
> > > >  doc/api/doxy-api.conf.in                      |   2 +-
> > > >  .../link_bonding_poll_mode_drv_lib.rst        |   2 +-
> > > >  doc/guides/testpmd_app_ug/testpmd_funcs.rst   |   2 +-
> > > >  drivers/common/mlx5/linux/meson.build         |   1 -
> > > >  drivers/meson.build                           |  85 ++++++--
> > > >  .../net/{bonding => bond}/bonding_testpmd.c   |   0
> > > >  .../eth_bond_8023ad_private.h                 |   0
> > > >  .../net/{bonding => bond}/eth_bond_private.h  |   0
> > > >  drivers/net/{bonding => bond}/meson.build     |   1 -
> > > >  drivers/net/{bonding => bond}/rte_eth_bond.h  |   0
> > > >  .../{bonding => bond}/rte_eth_bond_8023ad.c   |   0
> > > >  .../{bonding => bond}/rte_eth_bond_8023ad.h   |   0
> > > >  .../net/{bonding => bond}/rte_eth_bond_alb.c  |   0
> > > >  .../net/{bonding => bond}/rte_eth_bond_alb.h  |   0
> > > >  .../net/{bonding => bond}/rte_eth_bond_api.c  |   0
> > > >  .../net/{bonding => bond}/rte_eth_bond_args.c |   0
> > > >  .../net/{bonding => bond}/rte_eth_bond_flow.c |   0
> > > >  .../net/{bonding => bond}/rte_eth_bond_pmd.c  |   0
> > > >  drivers/net/intel/ice/meson.build             |   7 +-
> > > >  drivers/net/meson.build                       |   2 +-
> > > >  lib/acl/meson.build                           |   1 +
> > > >  lib/cfgfile/meson.build                       |   1 +
> > > >  lib/cryptodev/meson.build                     |   2 +-
> > > >  lib/dmadev/meson.build                        |   2 +-
> > > >  lib/eal/meson.build                           |   6 +-
> > > >  lib/ethdev/meson.build                        |   2 +-
> > > >  lib/eventdev/meson.build                      |   1 -
> > > >  lib/ipsec/meson.build                         |   2 +-
> > > >  lib/jobstats/meson.build                      |   1 +
> > > >  lib/log/meson.build                           |   1 -
> > > >  lib/mempool/meson.build                       |   2 +-
> > > >  lib/meson.build                               |  76 +++----
> > > >  lib/meter/meson.build                         |   1 +
> > > >  lib/metrics/meson.build                       |   2 +-
> > > >  lib/pci/meson.build                           |   1 +
> > > >  lib/ptr_compress/meson.build                  |   1 +
> > > >  lib/rawdev/meson.build                        |   2 +-
> > > >  lib/ring/meson.build                          |   2 +-
> > > >  lib/stack/meson.build                         |   1 +
> > > >  lib/timer/meson.build                         |   1 +
> > > >  meson.build                                   |  21 ++
> > > >  52 files changed, 478 insertions(+), 140 deletions(-)
> > > >  create mode 100644 buildtools/get-deps.py
> > > >  create mode 100644 buildtools/resolve-deps.py
> > > >  rename drivers/net/{bonding => bond}/bonding_testpmd.c (100%)
> > > >  rename drivers/net/{bonding => bond}/eth_bond_8023ad_private.h (100%)
> > > >  rename drivers/net/{bonding => bond}/eth_bond_private.h (100%)
> > > >  rename drivers/net/{bonding => bond}/meson.build (95%)
> > > >  rename drivers/net/{bonding => bond}/rte_eth_bond.h (100%)
> > > >  rename drivers/net/{bonding => bond}/rte_eth_bond_8023ad.c (100%)
> > > >  rename drivers/net/{bonding => bond}/rte_eth_bond_8023ad.h (100%)
> > > >  rename drivers/net/{bonding => bond}/rte_eth_bond_alb.c (100%)
> > > >  rename drivers/net/{bonding => bond}/rte_eth_bond_alb.h (100%)
> > > >  rename drivers/net/{bonding => bond}/rte_eth_bond_api.c (100%)
> > > >  rename drivers/net/{bonding => bond}/rte_eth_bond_args.c (100%)
> > > >  rename drivers/net/{bonding => bond}/rte_eth_bond_flow.c (100%)
> > > >  rename drivers/net/{bonding => bond}/rte_eth_bond_pmd.c (100%)
> > >
> > > Interesting series.
> > >
> > > I did not review in depth, but it seems promising.
> > > The first 4 (and maybe the 5th one) patches can go to 26.11 right now.
> > >
> > > I noticed a little formatting issue in patch 9 commitlog.
> > >
> > > One thing bothers me.. but I did not play enough with the options maybe...
> > >
> > > Could we use new build options (request_libs/apps/drivers or better named) ?
> > > This series changes the enable_libs/apps/drivers semantics and will
> > > likely result in confused users.
> > > (and we would need no support for mixing old and new options)
> > >
> > Can you clarify how it changes the semantic from a user viewpoint? Unless
> > I'm missing something, the only change is automatically fixing a broken
> > build for a user who didn't know the dependencies of the driver they want
> > enabled.
> 
> Well, the fact that everything becomes optional is a change in
> behavior, and enable_drivers=net/null not enabling ethdev is a problem
> to me.
> Or I misunderstood the last patch comments.
> 

Ok, I take the point, but that's actually a separate difference from the
majority of the changes. We can actually take the last patch and still keep
ethdev and other libraries as mandatory for compatibility. I just dropped
them since in the past we removed other libs from always_enable without
notice or compat concerns.

/Bruce