From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from dispatch1-us1.ppe-hosted.com (dispatch1-us1.ppe-hosted.com [67.231.154.164]) by dpdk.org (Postfix) with ESMTP id 5FFB91B926 for ; Fri, 11 Jan 2019 09:14:33 +0100 (CET) X-Virus-Scanned: Proofpoint Essentials engine Received: from webmail.solarflare.com (uk.solarflare.com [193.34.186.16]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-SHA384 (256/256 bits)) (No client certificate requested) by mx1-us3.ppe-hosted.com (Proofpoint Essentials ESMTP Server) with ESMTPS id 3B891980053; Fri, 11 Jan 2019 08:14:32 +0000 (UTC) Received: from [192.168.38.17] (91.220.146.112) by ukex01.SolarFlarecom.com (10.17.10.4) with Microsoft SMTP Server (TLS) id 15.0.1395.4; Fri, 11 Jan 2019 08:14:26 +0000 To: Yongseok Koh , , CC: , , References: <20190109085426.39965-1-yskoh@mellanox.com> <20190110183528.42503-1-yskoh@mellanox.com> From: Andrew Rybchenko Message-ID: <2934bc73-98e6-643a-0d61-cf7804e1535d@solarflare.com> Date: Fri, 11 Jan 2019 11:14:22 +0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.4.0 MIME-Version: 1.0 In-Reply-To: <20190110183528.42503-1-yskoh@mellanox.com> Content-Language: en-GB X-Originating-IP: [91.220.146.112] X-ClientProxiedBy: ocex03.SolarFlarecom.com (10.20.40.36) To ukex01.SolarFlarecom.com (10.17.10.4) X-TM-AS-Product-Ver: SMEX-12.5.0.1300-8.5.1010-24352.003 X-TM-AS-Result: No-14.266400-8.000000-10 X-TMASE-MatchedRID: 1GZI+iG+MtcOwH4pD14DsPHkpkyUphL9wx0jRRxcQfPmqBvJCEL6SgbO +kJftKhv2ODcUJmtdLGPhJhduqjE+uJVpHg0EXcOQ1OcCEvT+bebKpAlY2y6SVpbYq2f4jz+uHQ 5SWRKq/0Gt3hKlmvr3+454baurhScHVQV8h+E2Y4Cg1rav4R3DQeCHewokHM/FLXUWU5hGiFL2e 9EnNTTt3DnVnhp5tVEDohKTerxeO025XOhnouJ5SI9MxSOQ6CSXgqwd9ijktCjC1E/zCEIrwrxO vLvFPZPEeHflL4ZdKr9Vaa04yzrEbCq5jSQSB1nnTqdU4w65WkcDDLReGt4PfmUDxpFogQXo8WM kQWv6iUD0yuKrQIMCAGLeSok4rrZiYZyrULQL1ZsZUSYh+N/e+Gm0FoZM1lYyUR1um52tXxGWWv J17kDsxJYx2AXZqu9RLYybUA9kKDGWDv9cSIrn2EwBPvldXnJT7UFHUGxFVhjyGPRZz8teg== X-TM-AS-User-Approved-Sender: Yes X-TM-AS-User-Blocked-Sender: No X-TMASE-Result: 10--14.266400-8.000000 X-TMASE-Version: SMEX-12.5.0.1300-8.5.1010-24352.003 X-MDID: 1547194473-5tYupuHyeAt7 Content-Type: text/plain; charset="utf-8"; format=flowed Content-Transfer-Encoding: 7bit X-Content-Filtered-By: Mailman/MimeDel 2.1.15 Subject: Re: [dpdk-dev] [PATCH v3 1/2] mbuf: add function returning default buffer address 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: , X-List-Received-Date: Fri, 11 Jan 2019 08:14:33 -0000 On 1/10/19 9:35 PM, Yongseok Koh wrote: > This patch introduces two new functions - rte_mbuf_buf_addr() and > rte_mbuf_data_addr_default(). > > rte_mbuf_buf_addr() reutrns the default buffer address of given mbuf which > comes after mbuf structure and private data. > > rte_mbuf_data_addr_default() returns the default address of mbuf data > taking the headroom into account. > > Signed-off-by: Yongseok Koh > --- > > v3: > * rename functions > > v2: > * initial implementation > > lib/librte_mbuf/rte_mbuf.h | 43 ++++++++++++++++++++++++++++++++++++++++--- > 1 file changed, 40 insertions(+), 3 deletions(-) > > diff --git a/lib/librte_mbuf/rte_mbuf.h b/lib/librte_mbuf/rte_mbuf.h > index bc562dc8a9..486566fc28 100644 > --- a/lib/librte_mbuf/rte_mbuf.h > +++ b/lib/librte_mbuf/rte_mbuf.h > @@ -788,8 +788,47 @@ rte_mbuf_from_indirect(struct rte_mbuf *mi) > } > > /** > + * Return the default buffer address of the mbuf. > + * > + * @param mb > + * The pointer to the mbuf. > + * @param mp > + * The pointer to the mempool of the mbuf. > + * @return > + * The pointer of the mbuf buffer. > + */ > +static inline char * __rte_experimental > +rte_mbuf_buf_addr(struct rte_mbuf *mb, struct rte_mempool *mp) struct rte_mbuf has pool member. So, I don't understand why mp argument is required. I guess there is a reason, but it should be explained in comments. I see motivation in rte_mbuf_to_baddr() description, but rte_mbuf_buf_add() does not explain it. Also right now the function name looks like simple get accessor for buf_addr and I'd expect to seem one line implementation may be with extra debug checks: return mb->buf_addr. May be rte_mbuf_direct_buf_addr() ? If so, similar below rte_mbuf_direct_data_addr_default(). > +{ > + char *buffer_addr; > + > + buffer_addr = (char *)mb + sizeof(*mb) + rte_pktmbuf_priv_size(mp); > + return buffer_addr; > +} > + > + > +/** > + * Return the default address of the beginning of the mbuf data. > + * > + * @param mb > + * The pointer to the mbuf. > + * @return > + * The pointer of the beginning of the mbuf data. > + */ > +static inline char * __rte_experimental > +rte_mbuf_data_addr_default(struct rte_mbuf *mb) > +{ > + return rte_mbuf_buf_addr(mb, mb->pool) + RTE_PKTMBUF_HEADROOM; > +} > + > +/** > * Return the buffer address embedded in the given mbuf. > * > + * Note that accessing mempool pointer of a mbuf is expensive because the > + * pointer is stored in the 2nd cache line of mbuf. If mempool is known, it > + * is better not to reference the mempool pointer in mbuf but calling > + * rte_mbuf_buf_addr() would be more efficient. > + * > * @param md > * The pointer to the mbuf. > * @return > @@ -798,9 +837,7 @@ rte_mbuf_from_indirect(struct rte_mbuf *mi) > static inline char * > rte_mbuf_to_baddr(struct rte_mbuf *md) > { > - char *buffer_addr; > - buffer_addr = (char *)md + sizeof(*md) + rte_pktmbuf_priv_size(md->pool); > - return buffer_addr; > + return rte_mbuf_buf_addr(md, md->pool); > } > > /**