From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from mails.dpdk.org (mails.dpdk.org [217.70.189.124]) by smtp.lore.kernel.org (Postfix) with ESMTP id A1F99C5475B for ; Sun, 18 Feb 2024 13:07:30 +0000 (UTC) Received: from mails.dpdk.org (localhost [127.0.0.1]) by mails.dpdk.org (Postfix) with ESMTP id DAC234027A; Sun, 18 Feb 2024 14:07:29 +0100 (CET) Received: from dkmailrelay1.smartsharesystems.com (smartserver.smartsharesystems.com [77.243.40.215]) by mails.dpdk.org (Postfix) with ESMTP id DF94F40262 for ; Sun, 18 Feb 2024 14:07:27 +0100 (CET) Received: from smartserver.smartsharesystems.com (smartserver.smartsharesys.local [192.168.4.10]) by dkmailrelay1.smartsharesystems.com (Postfix) with ESMTP id AC22D2011D; Sun, 18 Feb 2024 14:07:27 +0100 (CET) Content-class: urn:content-classes:message MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Subject: RE: [PATCH v4 01/18] mbuf: deprecate GCC marker in rte mbuf struct X-MimeOLE: Produced By Microsoft Exchange V6.5 Date: Sun, 18 Feb 2024 14:07:25 +0100 Message-ID: <98CBD80474FA8B44BF855DF32C47DC35E9F22B@smartserver.smartshare.dk> In-Reply-To: <7561963.alqRGMn8q6@thomas> X-MS-Has-Attach: X-MS-TNEF-Correlator: Thread-Topic: [PATCH v4 01/18] mbuf: deprecate GCC marker in rte mbuf struct Thread-Index: AdpiZ5oldybi6nYqQjiW8mxxkErklwAAkTmw References: <1706657173-26166-1-git-send-email-roretzla@linux.microsoft.com> <1707978080-28859-1-git-send-email-roretzla@linux.microsoft.com> <1707978080-28859-2-git-send-email-roretzla@linux.microsoft.com> <7561963.alqRGMn8q6@thomas> From: =?iso-8859-1?Q?Morten_Br=F8rup?= To: "Thomas Monjalon" , , "Tyler Retzlaff" Cc: "Ajit Khaparde" , "Andrew Boyer" , "Andrew Rybchenko" , "Bruce Richardson" , "Chenbo Xia" , "Chengwen Feng" , "Dariusz Sosnowski" , "David Christensen" , "Hyong Youb Kim" , "Jerin Jacob" , "Jie Hai" , "Jingjing Wu" , "John Daley" , "Kevin Laatz" , "Kiran Kumar K" , "Konstantin Ananyev" , "Maciej Czekaj" , "Matan Azrad" , "Maxime Coquelin" , "Nithin Dabilpuram" , "Ori Kam" , "Ruifeng Wang" , "Satha Rao" , "Somnath Kotur" , "Suanming Mou" , "Sunil Kumar Kori" , "Viacheslav Ovsiienko" , "Yisen Zhuang" , "Yuying Zhang" X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org > From: Thomas Monjalon [mailto:thomas@monjalon.net] > Sent: Sunday, 18 February 2024 13.40 >=20 > 15/02/2024 07:21, Tyler Retzlaff: > > Provide a macro that allows conditional expansion of RTE_MARKER > fields > > to empty to allow rte_mbuf to be used with MSVC. It is proposed that > > we announce the fields to be __rte_deprecated (currently disabled). > > > > Introduce C11 anonymous unions to permit aliasing of well-known > > offsets by name into the rte_mbuf structure by a *new* name and to > > provide padding for cache alignment. > > > > Signed-off-by: Tyler Retzlaff > > --- > > doc/guides/rel_notes/deprecation.rst | 20 ++ > > lib/eal/include/rte_common.h | 6 + > > lib/mbuf/rte_mbuf_core.h | 375 = +++++++++++++++++++------ > ---------- > > 3 files changed, 233 insertions(+), 168 deletions(-) > > > > diff --git a/doc/guides/rel_notes/deprecation.rst > b/doc/guides/rel_notes/deprecation.rst > > index 10630ba..8594255 100644 > > --- a/doc/guides/rel_notes/deprecation.rst > > +++ b/doc/guides/rel_notes/deprecation.rst > > @@ -17,6 +17,26 @@ Other API and ABI deprecation notices are to be > posted below. > > Deprecation Notices > > ------------------- > > > > +* mbuf: Named zero sized fields of type ``RTE_MARKER`` and > ``RTE_MARKER64`` > > + will be removed from ``struct rte_mbuf`` and replaced with new > fields > > + in anonymous unions. > > + > > + The names of the fields impacted are: > > + > > + old name new name > > + > > + ``cacheline0`` ``mbuf_cachelin0`` > > + ``rearm_data`` ``mbuf_rearm_data`` > > + ``rx_descriptor_fields1`` ``mbuf_rx_descriptor_fields1`` > > + ``cacheline1`` ``mbuf_cachelin1`` > > + > > + Contributions to DPDK should immediately start using the new > names, > > + applications should adapt to new names as soon as possible as the > > + old names will be removed in a future DPDK release. > > + > > + Note: types of the new names are not API compatible with the old > and > > + some code conversion is required to maintain correct behavior. > > + > > * build: The ``enable_kmods`` option is deprecated and will be > removed in a future release. > > Setting/clearing the option has no impact on the build. > > Instead, kernel modules will be always built for OS's where out- > of-tree kernel modules > > diff --git a/lib/eal/include/rte_common.h > b/lib/eal/include/rte_common.h > > index d7d6390..af73f67 100644 > > --- a/lib/eal/include/rte_common.h > > +++ b/lib/eal/include/rte_common.h > > @@ -582,6 +582,12 @@ static void > __attribute__((destructor(RTE_PRIO(prio)), used)) func(void) > > /** Marker for 8B alignment in a structure. */ > > __extension__ typedef uint64_t RTE_MARKER64[0]; > > > > +#define __rte_marker(type, name) type name /* __rte_deprecated */ > > + > > +#else > > + > > +#define __rte_marker(type, name) > > + > > #endif > > > > /*********** Macros for calculating min and max **********/ > > diff --git a/lib/mbuf/rte_mbuf_core.h b/lib/mbuf/rte_mbuf_core.h > > index 5688683..9e9590b 100644 > > --- a/lib/mbuf/rte_mbuf_core.h > > +++ b/lib/mbuf/rte_mbuf_core.h > > @@ -16,7 +16,10 @@ > > * New fields and flags should fit in the "dynamic space". > > */ > > > > +#include > > +#include > > #include > > +#include > > > > #include > > #include > > @@ -464,204 +467,240 @@ enum { > > * The generic rte_mbuf, containing a packet mbuf. > > */ > > struct rte_mbuf { > > - RTE_MARKER cacheline0; > > - > > - void *buf_addr; /**< Virtual address of segment buffer. > */ > > + __rte_marker(RTE_MARKER, cacheline0); >=20 > You don't need to keep the first argument. > This would be simpler: > __rte_marker(cacheline0); > You just need to create 2 functions: __rte_marker and __rte_marker64. >=20 > You should replace all occurrences of RTE_MARKER in DPDK in one patch, > and mark RTE_MARKER as deprecated (use #pragma GCC poison) I like this suggestion. However, some applications might use RTE_MARKER in their own structures. Wouldn't it be considered API breakage to mark RTE_MARKER as deprecated? >=20 > > + union { > > + char mbuf_cacheline0[RTE_CACHE_LINE_MIN_SIZE]; > > + __extension__ > > + struct { > > + void *buf_addr; /**< Virtual address of > segment buffer. >=20 > I think it is ugly. >=20 > Changing mbuf API is a serious issue.