Minutes of Technical Board Meeting 2023-06-14

Minutes of Technical Board Meeting 2023-06-14

[Richardson, Bruce]

Attendees
----------
* Aaron
* Bruce
* Hemant
* Honnappa
* Jerin
* Kevin
* Maxime
* Thomas
* Morten
* Tyler
* Nathan
* Akhil
* David M.
* Dave Y.

NOTES:
* Next meeting on 2023-06-28 will be chaired by Hemant


General Updates
================

Documentation Rework
~~~~~~~~~~~~~~~~~~~~~

* Dave Young has started on DPDK project as technical writer
* Bruce and Nathan are currently acting as main points of contact but many
  queries are being handled via the DPDK #doc-rework slack channel
* There is an open invitation to all who wish to help out with
  documentation rework to join this channel - it's not just for TB members

Reviewers for DPDK Summit
~~~~~~~~~~~~~~~~~~~~~~~~~

* The call for papers for the DPDK summit has gone out.
* It is planned to review submissions at the start of July.
* Review panel to be made of tech-board members and others heavily involved
  in the project and regular techboard meeting attendees.

Agenda Discussion
=================

Managing Planned ABI changes
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

* Reviewed previous discussion on how to manage code changes which break
  ABI ahead of the next ABI-change release
* Decision to generally allow use of NEXT_ABI macro to include changes
  earlier while keeping stability when NEXT_ABI is off (the default)
* Each ABI change needs individual discussion before merging with NEXT_ABI
  to ensure easier or better solutions are not missed.

DPDK API Stability
~~~~~~~~~~~~~~~~~~

Issue raised that, while DPDK has an ABI stability policy, it does not have
an *API* stability policy.

It was suggested we introduce such a stability policy to match that of ABI
one, leading to much discussion.

* A number of people on the call reported feedback from users of the
  difficulty of moving DPDK releases because of API changes i.e. they had
  to change their own code, not just recompile.
* Presenters at previous DPDK conferences reported issues with e.g.
  open-source apps, trying to support multiple releases of DPDK underneath.
  The support requires much use of DPDK version-related ifdefs.
  This contrasts with other projects like VPP or OVS which only support a
  single DPDK release at a time, for the same reason.
* On the other hand, concern was expressed at how the imposition of API
  stability might impact feature delivery. We don't want new features held
  up for long periods.
* It was pointed out that much of our recent API change issues stem from
  cleanup of published macros/enums that don't have proper "RTE" prefixes.
  The hope is that the API will naturally be more stable now that this work
  is nearing completion.
* Beyond API changes specifically, concern was expressed with our current
  releases about:

  - changes of behaviour within functions without an API change, or ABI
    versioning to catch this
  - changes to behaviour or API not being properly documented in release
    notes
  - lack of rigour in our doxygen function documentation, e.g. lack of
    clarity on edge-case behaviour, and specifics of what error codes are
    returned.
  - use of error numbers as return codes, vs use of -1 & errno global, for
    flagging error. [Latter leads to more resiliency, especially when it
    comes to using switch statements for handing the documented error
    values, and a new error return code is added]

* Proposal was made to look at having 1 year API stability policy to match
  that of ABI policy.
* At end of discussion quorum was no longer present and no vote was taken
  on the issue at this point. It will be discussed further at later
  meetings.

---

All other agenda items postponed to a future meeting.