From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga02.intel.com (mga02.intel.com [134.134.136.20]) by dpdk.org (Postfix) with ESMTP id 6A5B27DF4 for ; Thu, 4 Dec 2014 03:08:49 +0100 (CET) Received: from orsmga001.jf.intel.com ([10.7.209.18]) by orsmga101.jf.intel.com with ESMTP; 03 Dec 2014 18:08:18 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.07,511,1413270000"; d="scan'208";a="618303950" Received: from pgsmsx103.gar.corp.intel.com ([10.221.44.82]) by orsmga001.jf.intel.com with ESMTP; 03 Dec 2014 18:08:16 -0800 Received: from shsmsx104.ccr.corp.intel.com (10.239.110.15) by PGSMSX103.gar.corp.intel.com (10.221.44.82) with Microsoft SMTP Server (TLS) id 14.3.195.1; Thu, 4 Dec 2014 10:08:15 +0800 Received: from shsmsx101.ccr.corp.intel.com ([169.254.1.110]) by SHSMSX104.ccr.corp.intel.com ([169.254.5.182]) with mapi id 14.03.0195.001; Thu, 4 Dec 2014 10:08:14 +0800 From: "Liu, Jijiang" To: Olivier MATZ Thread-Topic: [dpdk-dev] [PATCH v5 2/3] mbuf:add three TX ol_flags and repalce PKT_TX_VXLAN_CKSUM Thread-Index: AQHQDkIzZMvV7Xzwn0SVLY5kK7hoh5x9OYaAgAAV4YCAABxsgIABPOtw Date: Thu, 4 Dec 2014 02:08:13 +0000 Message-ID: <1ED644BD7E0A5F4091CF203DAFB8E4CC01D9FF2B@SHSMSX101.ccr.corp.intel.com> References: <1417532767-1309-1-git-send-email-jijiang.liu@intel.com> <1417532767-1309-3-git-send-email-jijiang.liu@intel.com> <547EF6E9.5040000@6wind.com> <2601191342CEEE43887BDE71AB977258213BC46D@IRSMSX105.ger.corp.intel.com> <547F211B.3040905@6wind.com> In-Reply-To: <547F211B.3040905@6wind.com> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [10.239.127.40] Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Cc: "dev@dpdk.org" Subject: Re: [dpdk-dev] [PATCH v5 2/3] mbuf:add three TX ol_flags and repalce PKT_TX_VXLAN_CKSUM X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: patches and discussions about DPDK List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 04 Dec 2014 02:08:50 -0000 Hi Olivier, > -----Original Message----- > From: Olivier MATZ [mailto:olivier.matz@6wind.com] > Sent: Wednesday, December 3, 2014 10:42 PM > To: Ananyev, Konstantin; Liu, Jijiang; dev@dpdk.org > Subject: Re: [dpdk-dev] [PATCH v5 2/3] mbuf:add three TX ol_flags and rep= alce > PKT_TX_VXLAN_CKSUM >=20 > Hi Konstantin, >=20 > On 12/03/2014 01:59 PM, Ananyev, Konstantin wrote: > >> I still think having a flag IPV4 + another flag IP_CHECKSUM is not > >> appropriate. > > > > Sorry, didn't get you here. > > Are you talking about our discussion should PKT_TX_IP_CKSUM and > PKT_TX_IPV4 be mutually exclusive or not? >=20 > Yes >=20 > >> I though Konstantin agreed on other flags, but I may have > >> misunderstood: > >> > >> http://dpdk.org/ml/archives/dev/2014-November/009070.html > > > > In that mail, I was talking about my suggestion to make PKT_TX_IP_CKSU= M, > PKT_TX_IPV4 and PKT_TX_IPV6 to occupy 2 bits. > > Something like: > > #define PKT_TX_IP_CKSUM (1 << X) > > #define PKT_TX_IPV6 (2 << X) > > #define PKT_TX_IPV4 (3 << X) > > > > "Even better, if we can squeeze these 3 flags into 2 bits. > > Would save us 2 bits, plus might be handy, as in the PMD you can do: > > > > switch (ol_flags & TX_L3_MASK) { > > case TX_IPV4: > > ... > > break; > > case TX_IPV6: > > ... > > break; > > case TX_IP_CKSUM: > > ... > > break; > > }" > > > > As you pointed out, it will break backward compatibility. > > I agreed with that and self-NACKed it. >=20 > ok, so we are back between: >=20 > 1/ (Jijiang's patch) > PKT_TX_IP_CKSUM /* packet is IPv4, and we want hw cksum */ > PKT_TX_IPV6 /* packet is IPv6 */ > PKT_TX_IPV4 /* packet is IPv4, and we don't want hw cksum */ >=20 > with PKT_TX_IP_CKSUM and PKT_TX_IPV4 exclusive >=20 > and >=20 > 2/ > PKT_TX_IP_CKSUM /* we want hw IP cksum */ > PKT_TX_IPV6 /* packet is IPv6 */ > PKT_TX_IPV4 /* packet is IPv4 */ >=20 > with PKT_TX_IP_CKSUM implies PKT_TX_IPV4 >=20 >=20 > Solution 2/ looks better from a user point of view. Anyone else has an op= inion? Let's think about these IPv4/6 flags in terms of checksum and IP version/ty= pe, =20 1. For IPv6=20 IP checksum is meaningful only for IPv4, so we define 'PKT_TX_IPV6 /*= packet is IPv6 */' to tell driver/HW that this is IPV6 packet, here we don= 't talk about the checksum for IPv6 as it is meaningless. Right? PKT_TX_IPV6 /* packet is IPv6 */ ------ IP type: v6; HW check= sum: meaningless 2. For IPv4, My patch: PKT_TX_IP_CKSUM /* packet is IPv4, and we want hw cksum */----------------= ----------IP type: v4; HW checksum: Yes PKT_TX_IPV4 /* packet is IPv4, and we don't want hw cksum */ ---------= -------------- IP type: v4; HW checksum: No You want: PKT_TX_IP_CKSUM /* we want hw IP cksum */-------------------------- IP typ= e: v4; HW checksum: Yes PKT_TX_IPV4 /* packet is IPv4*/ ------------------------ IP type: v4;= HW checksum: yes or no? = driver/HW don't know, just know this is packet = with IPv4 header.=20 = HW checksum: meaningless?? > Regards, > Olivier