From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: <konstantin.ananyev@intel.com> Received: from mga02.intel.com (mga02.intel.com [134.134.136.20]) by dpdk.org (Postfix) with ESMTP id 172473237 for <dev@dpdk.org>; Wed, 8 Apr 2015 15:45:05 +0200 (CEST) Received: from fmsmga002.fm.intel.com ([10.253.24.26]) by orsmga101.jf.intel.com with ESMTP; 08 Apr 2015 06:45:04 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.11,544,1422950400"; d="scan'208";a="705478660" Received: from irsmsx101.ger.corp.intel.com ([163.33.3.153]) by fmsmga002.fm.intel.com with ESMTP; 08 Apr 2015 06:45:03 -0700 Received: from irsmsx105.ger.corp.intel.com ([169.254.7.2]) by IRSMSX101.ger.corp.intel.com ([169.254.1.136]) with mapi id 14.03.0224.002; Wed, 8 Apr 2015 14:45:02 +0100 From: "Ananyev, Konstantin" <konstantin.ananyev@intel.com> To: Olivier MATZ <olivier.matz@6wind.com>, "dev@dpdk.org" <dev@dpdk.org> Thread-Topic: [PATCH v3 1/5] mbuf: fix clone support when application uses private mbuf data Thread-Index: AQHQa+gyjaiCAXJ/uUmIkTCvT5y80Z058RBAgAaNe4CAAQPAcIAAKOKAgAAVpxCAARfGAIAAUocQ Date: Wed, 8 Apr 2015 13:45:02 +0000 Message-ID: <2601191342CEEE43887BDE71AB97725821414805@irsmsx105.ger.corp.intel.com> References: <1427385595-15011-1-git-send-email-olivier.matz@6wind.com> <1427829784-12323-1-git-send-email-zer0@droids-corp.org> <1427829784-12323-2-git-send-email-zer0@droids-corp.org> <2601191342CEEE43887BDE71AB97725821413A2D@irsmsx105.ger.corp.intel.com> <5522FF6B.1030503@6wind.com> <2601191342CEEE43887BDE71AB97725821414310@irsmsx105.ger.corp.intel.com> <5523FB9B.2060508@6wind.com> <2601191342CEEE43887BDE71AB9772582141451F@irsmsx105.ger.corp.intel.com> <5524F876.8090900@6wind.com> In-Reply-To: <5524F876.8090900@6wind.com> Accept-Language: en-IE, en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [163.33.239.181] Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Subject: Re: [dpdk-dev] [PATCH v3 1/5] mbuf: fix clone support when application uses private mbuf data X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: patches and discussions about DPDK <dev.dpdk.org> List-Unsubscribe: <http://dpdk.org/ml/options/dev>, <mailto:dev-request@dpdk.org?subject=unsubscribe> List-Archive: <http://dpdk.org/ml/archives/dev/> List-Post: <mailto:dev@dpdk.org> List-Help: <mailto:dev-request@dpdk.org?subject=help> List-Subscribe: <http://dpdk.org/ml/listinfo/dev>, <mailto:dev-request@dpdk.org?subject=subscribe> X-List-Received-Date: Wed, 08 Apr 2015 13:45:06 -0000 Hi Olivier, > -----Original Message----- > From: Olivier MATZ [mailto:olivier.matz@6wind.com] > Sent: Wednesday, April 08, 2015 10:44 AM > To: Ananyev, Konstantin; dev@dpdk.org > Cc: zoltan.kiss@linaro.org; Richardson, Bruce > Subject: Re: [PATCH v3 1/5] mbuf: fix clone support when application uses= private mbuf data >=20 > Hi Konstantin, >=20 > On 04/07/2015 07:17 PM, Ananyev, Konstantin wrote: > >> Just to be sure we're on the same line: > >> > >> - before the patch series > >> > >> - private area was working before that patch series if clones were= not > >> used. To use a private are, the user had to provide another > >> function derived from pktmbuf_init() to change m->buf_addr and > >> m->buf_len. > >> - using both private area + clones was broken > >> > >> - after the patch series > >> > >> - private area is working with or without clone. But yo use it, > >> the user still has to provide another function to change > >> m->buf_addr, m->buf_len *and m->priv_size*. > >> > >> The series just fixes the fact that "clones + priv" was not working. > >> It does not address the problem that providing a new pktmbuf_init() > >> function is required to use privata area. To fix this, I think it > >> could require a API evolution that should be part of another series. > > > > I don't think we need new pktmbuf_init(). > > We just need to update it, so both pktmbuf_init() and detach() setup > > buf_addr, buf_len (and priv_size) to exactly the same values. > > If they don't do that, it means that you can't use attach/detach with > > mempools created with pktmbuf_init() any more. > > > > BTW, another thing that I just realised: > > examples/ipv4_multicast and examples/ip_fragmentation/ - > > both create a pool of mbufs with elem_size < 2K and don't populate memp= ool's private area - > > so mbp_priv->mbuf_data_room_size =3D=3D 0, for them. > > > > So that code in detach(): > > > > + mbp_priv =3D rte_mempool_get_priv(mp); > > + m->priv_size =3D mp->elt_size - RTE_PKTMBUF_HEADROOM - > > + mbp_priv->mbuf_data_room_size - > > + sizeof(struct rte_mbuf); > > > > > > Would break both these samples. > > I suppose we need to handle situation when mp->elt_size < RTE_PKTMBUF_H= EADROOM + sizeof(struct rte_mbuf), > > (and probably also when mbuf_data_room_size =3D=3D 0) correctly. >=20 > Indeed. I think a mbuf pool (even with buf_len =3D=3D 0 like in > ip_fragmentation example) should have a pool with a private area and > should call rte_pktmbuf_pool_init() to populate it. So > rte_pktmbuf_pool_init() has to be fixed first to use elt_size > and support the buf_len < RTE_PKTMBUF_HEADROOM, then we can > update frag/multicast examples. >=20 > Unfortunately, we don't know the size of the mbuf private area > in rte_pktmbuf_pool_init() if the opaque arg (data_room_size) > is 0, which is the default. I think it should be replaced by a structure > containing data_room_size and mbuf_priv_size, but it would break > applications that are setting data_room_size. Yes, same thoughts here. > I don't see any good > solution to do that while keeping a backward compatibility for > rte_pktmbuf_pool_init(), but as the current API is not ideal, > I think it's worth changing it and add something in the release > note. If no one else has a better alternative than that, then I suppose it is goo= d enough.=20 >=20 > We may also want to introduce a new helper as discussed previously: >=20 > struct rte_mempool * > rte_pktmbuf_pool_create(const char *name, unsigned n, unsigned elt_size, > unsigned cache_size, size_t mbuf_priv_size, > rte_mempool_obj_ctor_t *obj_init, void *obj_init_arg, > int socket_id, unsigned flags) >=20 > Any comment? Looks good to me. Should we also introduce rte_pktmbuf_pool_xmem_create()?=20 Konstantin >=20 >=20 > > > > Konstantin