From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: <dev-bounces@dpdk.org> Received: from dpdk.org (dpdk.org [92.243.14.124]) by inbox.dpdk.org (Postfix) with ESMTP id 82D4CA0093; Fri, 22 May 2020 06:30:24 +0200 (CEST) Received: from [92.243.14.124] (localhost [127.0.0.1]) by dpdk.org (Postfix) with ESMTP id E87491D8D8; Fri, 22 May 2020 06:30:23 +0200 (CEST) Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by dpdk.org (Postfix) with ESMTP id BF6941D73C for <dev@dpdk.org>; Fri, 22 May 2020 06:30:21 +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 0633231B; Thu, 21 May 2020 21:30:21 -0700 (PDT) Received: from qc2400f-1.austin.arm.com (qc2400f-1.austin.arm.com [10.118.14.48]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id E4DC33F305; Thu, 21 May 2020 21:30:20 -0700 (PDT) From: Honnappa Nagarahalli <honnappa.nagarahalli@arm.com> To: dev@dpdk.org, konstantin.ananyev@intel.com, stephen@networkplumber.org, jerinj@marvell.com, hemant.agrawal@nxp.com Cc: ruifeng.wang@arm.com, phil.yang@arm.com, honnappa.nagarahalli@arm.com, nd@arm.com Date: Thu, 21 May 2020 23:30:13 -0500 Message-Id: <20200522043013.12535-1-honnappa.nagarahalli@arm.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <1588835193-27550-1-git-send-email-phil.yang@arm.com> References: <1588835193-27550-1-git-send-email-phil.yang@arm.com> Subject: [dpdk-dev] [PATCH v2] doc: announce adoption of C11 atomic operations semantics X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 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> 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: Hemant Agrawal <hemant.agrawal@nxp.com> Acked-by: Jerin Jacob <jerinj@marvell.com> --- doc/guides/rel_notes/deprecation.rst | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/doc/guides/rel_notes/deprecation.rst b/doc/guides/rel_notes/deprecation.rst index 20aa745b7..01f99a0d6 100644 --- a/doc/guides/rel_notes/deprecation.rst +++ b/doc/guides/rel_notes/deprecation.rst @@ -113,3 +113,16 @@ 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. 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. -- 2.17.1