[dpdk-dev] [PATCH v5 00/41] Pipeline alignment with the P4 language

[David Marchand]

On Wed, Sep 23, 2020 at 8:06 PM Cristian Dumitrescu
<cristian.dumitrescu at intel.com> wrote:
>
> This patch set introduces a new pipeline type that combines the DPDK
> performance with the flexibility of the P4-16 language[1]. The new API
> can be used either by itself to code a complete software switch (SWX)
> or data plane app, or in combination with the open-source P4 compiler
> P4C [2], potentially acting as a P4C back-end, thus allowing the P4
> programs to be translated to the DPDK API and run on multi-core CPUs.
>
> Main new features:
>
> * Nothing is hard-wired, everything is dynamically defined: The packet
>   headers (i.e. protocols), the packet meta-data, the actions, the
>   tables and the pipeline itself are dynamically defined instead of
>   having to be selected from a pre-defined set.
>
> * Instructions: The actions and the life of the packet through the
>   pipeline are defined with instructions that manipulate the pipeline
>   objects mentioned above. The pipeline is the main function of the
>   packet program, with actions as subroutines triggered by the tables.
>
> * Call external plugins: Extern objects and functions can be defined
>   to call functionality that cannot be efficiently implemented with
>   the existing pipeline-oriented instruction set, such as: special
>   error detecting/correcting codes, crypto, meters, stats arrays,
>   heuristics, etc.
>
> * Better control plane interaction: Transaction-oriented table update
>   mechanism that supports multi-table atomic updates. Multiple tables
>   can be updated in a single step with only the before and after table
>   sets visible to the packets. Alignment with P4Runtime [3].
>
> * Performance: Multiple packets are in-flight within the pipeline at
>   any moment. Each packet is owned by a different time-sharing thread
>   in run-to-completion, with the thread pausing before memory access
>   operations such as packet I/O and table lookup to allow the memory
>   prefetch to complete. The instructions are verified and translated
>   at initialization time with no run-time impact. The instructions are
>   also optimized to detect and "fuse" frequently used patterns into
>   vector-like instructions transparently to the user.
>
> API deprecation and maturing roadmap:
> * The existing pipeline stable API (rte_pipeline.h) to be deprecated
>   prior to and removed as part of the DPDK 21.11 LTS release.
> * The new SWX pipeline experimental API (rte_swx_pipeline.h) to mature
>   and become stable as part of the same DPDK 21.11 LTS release.

This is a new feature: we are missing a release note update as part of
the series.


-- 
David Marchand