From mboxrd@z Thu Jan 1 00:00:00 1970
Return-Path: <dev-bounces@dpdk.org>
Received: from mails.dpdk.org (mails.dpdk.org [217.70.189.124])
by inbox.dpdk.org (Postfix) with ESMTP id 2A68FA0C46;
Fri, 23 Jul 2021 11:51:05 +0200 (CEST)
Received: from [217.70.189.124] (localhost [127.0.0.1])
by mails.dpdk.org (Postfix) with ESMTP id 1585E40040;
Fri, 23 Jul 2021 11:51:05 +0200 (CEST)
Received: from foss.arm.com (foss.arm.com [217.140.110.172])
by mails.dpdk.org (Postfix) with ESMTP id 01D204003C;
Fri, 23 Jul 2021 11:51:04 +0200 (CEST)
Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14])
by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 37F4F113E;
Fri, 23 Jul 2021 02:51:03 -0700 (PDT)
Received: from net-arm-n1sdp.shanghai.arm.com (net-arm-n1sdp.shanghai.arm.com
[10.169.208.222])
by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 9A28A3F694;
Fri, 23 Jul 2021 02:51:00 -0700 (PDT)
From: Joyce Kong <joyce.kong@arm.com>
To: thomas@monjalon.net, stephen@networkplumber.org,
honnappa.nagarahalli@arm.com, ruifeng.wang@arm.com, mdr@ashroe.eu
Cc: dev@dpdk.org,
nd@arm.com,
stable@dpdk.org
Date: Fri, 23 Jul 2021 04:49:43 -0500
Message-Id: <20210723094943.7203-1-joyce.kong@arm.com>
X-Mailer: git-send-email 2.17.1
In-Reply-To: <20210712080237.19920-1-joyce.kong@arm.com>
References: <20210712080237.19920-1-joyce.kong@arm.com>
Subject: [dpdk-dev] [PATCH v2] doc: update atomic operation deprecation
X-BeenThere: dev@dpdk.org
X-Mailman-Version: 2.1.29
Precedence: list
List-Id: DPDK patches and discussions <dev.dpdk.org>
List-Unsubscribe: <https://mails.dpdk.org/options/dev>,
<mailto:dev-request@dpdk.org?subject=unsubscribe>
List-Archive: <http://mails.dpdk.org/archives/dev/>
List-Post: <mailto:dev@dpdk.org>
List-Help: <mailto:dev-request@dpdk.org?subject=help>
List-Subscribe: <https://mails.dpdk.org/listinfo/dev>,
<mailto:dev-request@dpdk.org?subject=subscribe>
Errors-To: dev-bounces@dpdk.org
Sender: "dev" <dev-bounces@dpdk.org>
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 | 18 ++++++++++--------
1 file changed, 10 insertions(+), 8 deletions(-)
diff --git a/doc/guides/rel_notes/deprecation.rst b/doc/guides/rel_notes/deprecation.rst
index 9584d6bfd7..a4f350fa09 100644
--- a/doc/guides/rel_notes/deprecation.rst
+++ b/doc/guides/rel_notes/deprecation.rst
@@ -19,16 +19,18 @@ 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 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 operations from
+ https://gcc.gnu.org/onlinedocs/gcc/_005f_005fatomic-Builtins.html. These
+ operations 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
--
2.17.1