[v1] doc: update atomic operation deprecation
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Commit Message
Update the incorrect description about atomic operations
with provided wrappers in deprecation doc[1].
[1]https://mails.dpdk.org/archives/dev/2021-July/213333.html
Fixes: 7518c5c4ae6a ("doc: announce adoption of C11 atomic operations semantics")
Cc: stable@dpdk.org
Signed-off-by: Joyce Kong <joyce.kong@arm.com>
Reviewed-by: Ruifeng Wang <ruifeng.wang@arm.com>
---
doc/guides/rel_notes/deprecation.rst | 16 ++++++++--------
1 file changed, 8 insertions(+), 8 deletions(-)
Comments
<snip>
>
> Update the incorrect description about atomic operations with provided
> wrappers in deprecation doc[1].
>
> [1]https://mails.dpdk.org/archives/dev/2021-July/213333.html
>
> Fixes: 7518c5c4ae6a ("doc: announce adoption of C11 atomic operations
> semantics")
> Cc: stable@dpdk.org
>
> Signed-off-by: Joyce Kong <joyce.kong@arm.com>
> Reviewed-by: Ruifeng Wang <ruifeng.wang@arm.com>
> ---
> doc/guides/rel_notes/deprecation.rst | 16 ++++++++--------
> 1 file changed, 8 insertions(+), 8 deletions(-)
>
> diff --git a/doc/guides/rel_notes/deprecation.rst
> b/doc/guides/rel_notes/deprecation.rst
> index 9584d6bfd7..4142315842 100644
> --- a/doc/guides/rel_notes/deprecation.rst
> +++ b/doc/guides/rel_notes/deprecation.rst
> @@ -19,16 +19,16 @@ Deprecation Notices
>
> * 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. This change will not introduce any
> - performance degradation.
> + in DPDK. DPDK has adopted atomic operations semantics. GCC atomic
> + built-ins must be used for patches that need to be merged in 20.08
> + onwards. This change will not introduce any performance degradation.
Since there have been objections to the language used to refer to GCC C11 atomic built-ins, may be we add a reference to the GCC pages?
DPDK has adopted the atomic operations from https://gcc.gnu.org/onlinedocs/gcc/_005f_005fatomic-Builtins.html. These operations must be used for patches that need to be merged in 20.08 onwards. This change will not introduce any performance degradation.
>
> * 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. This change will not introduce any performance degradation.
> + use cases do not require full barriers. To support such use cases,
> + DPDK has adopted atomic barrier semantics. GCC atomic built-ins and a
> + new wrapper ``rte_atomic_thread_fence`` instead of
> + ``__atomic_thread_fence`` must be used for patches that need to be
> + merged in 20.08 onwards. This change will not introduce any performance
> degradation.
Same here.
To support such use cases, DPDK has adopted atomic operations from https://gcc.gnu.org/onlinedocs/gcc/_005f_005fatomic-Builtins.html. A new wrapper ``rte_atomic_thread_fence`` instead of ``__atomic_thread_fence`` must be used for patches that need to be merged in 20.08 onwards. This change will not introduce any performance degradation.
>
> * lib: will fix extending some enum/define breaking the ABI. There are
> multiple
> samples in DPDK that enum/define terminated with a ``.*MAX.*`` value
> which is
> --
> 2.17.1
@@ -19,16 +19,16 @@ Deprecation Notices
* 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. This change will not introduce any
- performance degradation.
+ in DPDK. DPDK has adopted atomic operations semantics. GCC atomic built-ins
+ must be used for patches that need to be merged in 20.08 onwards. This change
+ will not introduce any performance degradation.
* 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. This change will not introduce any performance degradation.
+ use cases do not require full barriers. To support such use cases, DPDK has
+ adopted atomic barrier semantics. GCC atomic built-ins and a new wrapper
+ ``rte_atomic_thread_fence`` instead of ``__atomic_thread_fence`` must be
+ used for patches that need to be merged in 20.08 onwards. This change will
+ not introduce any performance degradation.
* lib: will fix extending some enum/define breaking the ABI. There are multiple
samples in DPDK that enum/define terminated with a ``.*MAX.*`` value which is