From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from dpdk.org (dpdk.org [92.243.14.124]) by inbox.dpdk.org (Postfix) with ESMTP id 463E9A318B for ; Fri, 18 Oct 2019 10:28:09 +0200 (CEST) Received: from [92.243.14.124] (localhost [127.0.0.1]) by dpdk.org (Postfix) with ESMTP id 04E0F1C11E; Fri, 18 Oct 2019 10:28:09 +0200 (CEST) Received: from mga03.intel.com (mga03.intel.com [134.134.136.65]) by dpdk.org (Postfix) with ESMTP id 745881C11D for ; Fri, 18 Oct 2019 10:28:06 +0200 (CEST) X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga007.jf.intel.com ([10.7.209.58]) by orsmga103.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 18 Oct 2019 01:28:05 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.67,311,1566889200"; d="scan'208";a="186760742" Received: from fmsmsx105.amr.corp.intel.com ([10.18.124.203]) by orsmga007.jf.intel.com with ESMTP; 18 Oct 2019 01:28:05 -0700 Received: from fmsmsx157.amr.corp.intel.com (10.18.116.73) by FMSMSX105.amr.corp.intel.com (10.18.124.203) with Microsoft SMTP Server (TLS) id 14.3.439.0; Fri, 18 Oct 2019 01:28:05 -0700 Received: from shsmsx153.ccr.corp.intel.com (10.239.6.53) by FMSMSX157.amr.corp.intel.com (10.18.116.73) with Microsoft SMTP Server (TLS) id 14.3.439.0; Fri, 18 Oct 2019 01:28:04 -0700 Received: from shsmsx102.ccr.corp.intel.com ([169.254.2.176]) by SHSMSX153.ccr.corp.intel.com ([10.239.6.53]) with mapi id 14.03.0439.000; Fri, 18 Oct 2019 16:28:02 +0800 From: "Wang, Haiyue" To: Olivier Matz CC: "dev@dpdk.org" , Andrew Rybchenko , "Richardson, Bruce" , Jerin Jacob Kollanukkaran , "Wiles, Keith" , "Ananyev, Konstantin" , =?iso-8859-1?Q?Morten_Br=F8rup?= , Stephen Hemminger , Thomas Monjalon Thread-Topic: [PATCH v2] mbuf: support dynamic fields and flags Thread-Index: AQHVhPkmy3Bf3WM2d0mLozWwBzvtDqdfncww///kgACAAI1y0A== Date: Fri, 18 Oct 2019 08:28:02 +0000 Message-ID: References: <20190710092907.5565-1-olivier.matz@6wind.com> <20191017144219.32708-1-olivier.matz@6wind.com> <20191018075350.bxrcsxhsgu2uaph7@platinum> In-Reply-To: <20191018075350.bxrcsxhsgu2uaph7@platinum> Accept-Language: zh-CN, en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-titus-metadata-40: eyJDYXRlZ29yeUxhYmVscyI6IiIsIk1ldGFkYXRhIjp7Im5zIjoiaHR0cDpcL1wvd3d3LnRpdHVzLmNvbVwvbnNcL0ludGVsMyIsImlkIjoiOWMzOTljODgtNzE2NS00ZWRhLTkyNjctYjg3MzlmYmRkYjU1IiwicHJvcHMiOlt7Im4iOiJDVFBDbGFzc2lmaWNhdGlvbiIsInZhbHMiOlt7InZhbHVlIjoiQ1RQX05UIn1dfV19LCJTdWJqZWN0TGFiZWxzIjpbXSwiVE1DVmVyc2lvbiI6IjE3LjEwLjE4MDQuNDkiLCJUcnVzdGVkTGFiZWxIYXNoIjoiUWhWS0lDa1Fnb1A4NXRXVFF5UjBERU51SWVBYWh2QTlOa0xla013cmEwMjI3K2VcL0hYUCszMkd0UHJmMkh3WTYifQ== x-ctpclassification: CTP_NT dlp-product: dlpe-windows dlp-version: 11.2.0.6 dlp-reaction: no-action x-originating-ip: [10.239.127.40] Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Subject: Re: [dpdk-dev] [PATCH v2] mbuf: support dynamic fields and flags X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Sender: "dev" Hi Olivier, > -----Original Message----- > From: Olivier Matz [mailto:olivier.matz@6wind.com] > Sent: Friday, October 18, 2019 15:54 > To: Wang, Haiyue > Cc: dev@dpdk.org; Andrew Rybchenko ; Richardso= n, Bruce > ; Jerin Jacob Kollanukkaran ; Wiles, Keith > ; Ananyev, Konstantin ; Morten Br=F8rup > ; Stephen Hemminger ; Thomas Monjalon > > Subject: Re: [PATCH v2] mbuf: support dynamic fields and flags >=20 > Hi Haiyue, >=20 > On Fri, Oct 18, 2019 at 02:47:50AM +0000, Wang, Haiyue wrote: > > Hi Olivier > > > > > -----Original Message----- > > > From: Olivier Matz [mailto:olivier.matz@6wind.com] > > > Sent: Thursday, October 17, 2019 22:42 > > > To: dev@dpdk.org > > > Cc: Andrew Rybchenko ; Richardson, Bruce <= bruce.richardson@intel.com>; > Wang, > > > Haiyue ; Jerin Jacob Kollanukkaran ; Wiles, Keith > > > ; Ananyev, Konstantin ; Morten Br=F8rup > > > ; Stephen Hemminger ; Thomas Monjalon > > > > > > Subject: [PATCH v2] mbuf: support dynamic fields and flags > > > > > > Many features require to store data inside the mbuf. As the room in m= buf > > > structure is limited, it is not possible to have a field for each > > > feature. Also, changing fields in the mbuf structure can break the AP= I > > > or ABI. > > > > > > This commit addresses these issues, by enabling the dynamic registrat= ion > > > of fields or flags: > > > > > > - a dynamic field is a named area in the rte_mbuf structure, with a > > > given size (>=3D 1 byte) and alignment constraint. > > > - a dynamic flag is a named bit in the rte_mbuf structure. > > > > > > The typical use case is a PMD that registers space for an offload > > > feature, when the application requests to enable this feature. As > > > the space in mbuf is limited, the space should only be reserved if it > > > is going to be used (i.e when the application explicitly asks for it)= . > > > > > > The registration can be done at any moment, but it is not possible > > > to unregister fields or flags for now. > > > > > > Signed-off-by: Olivier Matz > > > Acked-by: Thomas Monjalon > > > --- > > > > > > v2 > > > > > > * Rebase on top of master: solve conflict with Stephen's patchset > > > (packet copy) > > > * Add new apis to register a dynamic field/flag at a specific place > > > * Add a dump function (sugg by David) > > > * Enhance field registration function to select the best offset, keep= ing > > > large aligned zones as much as possible (sugg by Konstantin) > > > * Use a size_t and unsigned int instead of int when relevant > > > (sugg by Konstantin) > > > * Use "uint64_t dynfield1[2]" in mbuf instead of 2 uint64_t fields > > > (sugg by Konstantin) > > > * Remove unused argument in private function (sugg by Konstantin) > > > * Fix and simplify locking (sugg by Konstantin) > > > * Fix minor typo > > > > > > rfc -> v1 > > > > > > * Rebase on top of master > > > * Change registration API to use a structure instead of > > > variables, getting rid of #defines (Stephen's comment) > > > * Update flag registration to use a similar API as fields. > > > * Change max name length from 32 to 64 (sugg. by Thomas) > > > * Enhance API documentation (Haiyue's and Andrew's comments) > > > * Add a debug log at registration > > > * Add some words in release note > > > * Did some performance tests (sugg. by Andrew): > > > On my platform, reading a dynamic field takes ~3 cycles more > > > than a static field, and ~2 cycles more for writing. > > > > > > app/test/test_mbuf.c | 145 ++++++- > > > doc/guides/rel_notes/release_19_11.rst | 7 + > > > lib/librte_mbuf/Makefile | 2 + > > > lib/librte_mbuf/meson.build | 6 +- > > > lib/librte_mbuf/rte_mbuf.h | 23 +- > > > lib/librte_mbuf/rte_mbuf_dyn.c | 548 +++++++++++++++++++++++= ++ > > > lib/librte_mbuf/rte_mbuf_dyn.h | 226 ++++++++++ > > > lib/librte_mbuf/rte_mbuf_version.map | 7 + > > > 8 files changed, 959 insertions(+), 5 deletions(-) > > > create mode 100644 lib/librte_mbuf/rte_mbuf_dyn.c > > > create mode 100644 lib/librte_mbuf/rte_mbuf_dyn.h > > > > > > diff --git a/app/test/test_mbuf.c b/app/test/test_mbuf.c > > > index b9c2b2500..01cafad59 100644 > > > --- a/app/test/test_mbuf.c > > > +++ b/app/test/test_mbuf.c > > > @@ -28,6 +28,7 @@ > > > #include > > > > [snip] > > > > > +/** > > > + * Helper macro to access to a dynamic field. > > > + */ > > > +#define RTE_MBUF_DYNFIELD(m, offset, type) ((type)((uintptr_t)(m) + = (offset))) > > > + > > > > The suggested macro is missed ? ;-) > > /** > > * Helper macro to access to a dynamic flag. > > */ > > #define RTE_MBUF_DYNFLAG(offset) (1ULL << (offset)) >=20 > Yes, sorry. >=20 > Thinking a bit more about it, I wonder if the macros below aren't > more consistent with the dynamic field (because they take the mbuf > as parameter)? >=20 > #define RTE_MBUF_SET_DYNFLAG(m, bitnum, val) ... > #define RTE_MBUF_GET_DYNFLAG(m, bitnum) ... >=20 > They could even be static inline functions. >=20 > On the other hand, these helpers would be generic to ol_flags, not only > for dynamic flags. Today, we use (1ULL << bit) for ol_flags, which makes > me wonder... is the macro really needed after all? :) >=20 I used as this: 1). in PMD: mb->ol_flags |=3D RTE_MBUF_DYNFLAG(ol_offset);=20 2). In testpmd if (mb->ol_flags & RTE_MBUF_DYNFLAG(ol_offset)) ... The above two macros look better in real use. > > BTW, should we have a place to put the registered dynamic fields and fl= ags > > names together (a name overview -- detail Link to --> PMD's help page) = ? >=20 > The centralized place will be in rte_mbuf_dyn.h for fields/flags that can > are shared between several dpdk areas. Some libraries/pmd could have priv= ate > dynamic fields/flags. In any case, I think the same namespace than functi= ons > should be used. Probably something like this: > - "rte_mbuf_dynfield_" in mbuf lib > - "rte__dynfield_" in other libs > - "rte_net__dynfield_" in pmds > - "" in apps >=20 > > Since rte_mbuf_dynfield:name & rte_mbuf_dynflag:name work as a API styl= e, > > users can check how many 'names' registered, developers can check wheth= er > > the names they want to use are registered or not ? They don't need to h= ave > > to check the rte_errno ... Just a suggestion for user experience. >=20 > I did not get you point. Does my response above answers to your question? >=20 Yes, the name conversation you mentioned above is a good practice, then no = doc needed any more, thanks! > Regards, > Olivier