Re: [dpdk-dev] [PATCH] doc: announce adoption of C11 atomic operations semantics

[Jerin Jacob <jerinjacobk@gmail.com>]

On Thu, May 7, 2020 at 12:38 PM Phil Yang <phil.yang@arm.com> wrote:
>
> From: Honnappa Nagarahalli <honnappa.nagarahalli@arm.com>
>
> As agreed in the DPDK tech board [1], after 20.05 release, patches must
> use C11 atomic operations semantics with the help of wrappers.
>
> [1] http://mails.dpdk.org/archives/dev/2020-April/165143.html
>
> Signed-off-by: Honnappa Nagarahalli <honnappa.nagarahalli@arm.com>
> Reviewed-by: Phil Yang <phil.yang@arm.com>
> Reviewed-by: Ruifeng Wang <ruifeng.wang@arm.com>


Acked-by: Jerin Jacob <jerinj@marvell.com>



> ---
>  doc/guides/rel_notes/deprecation.rst | 12 ++++++++++++
>  1 file changed, 12 insertions(+)
>
> diff --git a/doc/guides/rel_notes/deprecation.rst b/doc/guides/rel_notes/deprecation.rst
> index 20aa745..208708d 100644
> --- a/doc/guides/rel_notes/deprecation.rst
> +++ b/doc/guides/rel_notes/deprecation.rst
> @@ -113,3 +113,15 @@ Deprecation Notices
>    Python 2 support will be completely removed in 20.11.
>    In 20.08, explicit deprecation warnings will be displayed when running
>    scripts with Python 2.
> +
> +* rte_atomicNN_xxx: These APIs do not take memory order parameter. This does
> +  not allow for writing optimized code for all the CPU architectures supported
> +  in DPDK. DPDK will adopt C11 atomic operations semantics and provide wrappers
> +  using C11 atomic built-ins. These wrappers must be used for patches that
> +  need to be merged in 20.08 onwards.
> +
> +* rte_smp_*mb: These APIs provide full barrier functionality. However, many
> +  use cases do not require full barriers. To support such use cases, DPDK will
> +  adopt C11 barrier semantics and provide wrappers using C11 atomic built-ins.
> +  These wrappers must be used for patches that need to be merged in 20.08
> +  onwards.
> --
> 2.7.4
>