From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx0b-000f0801.pphosted.com (mx0b-000f0801.pphosted.com [67.231.152.113]) by dpdk.org (Postfix) with ESMTP id F3FD82A9 for ; Fri, 13 Dec 2013 00:06:46 +0100 (CET) Received: from pps.filterd (m0000700 [127.0.0.1]) by mx0b-000f0801.pphosted.com (8.14.5/8.14.5) with SMTP id rBCMlfB2016410; Thu, 12 Dec 2013 15:07:51 -0800 Received: from hq1wp-exchub01.corp.brocade.com ([144.49.131.13]) by mx0b-000f0801.pphosted.com with ESMTP id 1gpwn39btq-1 (version=TLSv1/SSLv3 cipher=AES128-SHA bits=128 verify=NOT); Thu, 12 Dec 2013 15:07:51 -0800 Received: from HQ1WP-EXHUB01.corp.brocade.com (10.70.36.14) by HQ1WP-EXCHUB01.corp.brocade.com (10.70.36.99) with Microsoft SMTP Server (TLS) id 14.3.123.3; Thu, 12 Dec 2013 15:07:50 -0800 Received: from HQ1-EXCH02.corp.brocade.com ([fe80::c92a:772e:befa:c34c]) by HQ1WP-EXHUB01.corp.brocade.com ([::1]) with mapi; Thu, 12 Dec 2013 15:07:40 -0800 From: Pashupati Kumar To: Jose Gavine Cueto , "dev@dpdk.org" Date: Thu, 12 Dec 2013 15:07:39 -0800 Thread-Topic: [dpdk-dev] kni vs. pmd Thread-Index: Ac71/cij6wpSe02iQnG83zQcHYvCrgBjyjRg Message-ID: <6895EAE0CA8DEE40B92D7CA88BB521F332BA573240@HQ1-EXCH02.corp.brocade.com> References: In-Reply-To: Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: acceptlanguage: en-US Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:5.11.87, 1.0.14, 0.0.0000 definitions=2013-12-12_05:2013-12-12,2013-12-12,1970-01-01 signatures=0 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 spamscore=0 suspectscore=0 phishscore=0 adultscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=7.0.1-1305240000 definitions=main-1312120134 Subject: Re: [dpdk-dev] kni vs. pmd 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, 12 Dec 2013 23:06:47 -0000 > -----Original Message----- > From: dev [mailto:dev-bounces@dpdk.org] On Behalf Of Jose Gavine Cueto > Sent: Tuesday, December 10, 2013 3:16 PM > To: dev@dpdk.org > Subject: Re: [dpdk-dev] kni vs. pmd >=20 > Additional question: >=20 > Apart from the possible fact that kni performs zero-copy in the driver la= yer, > does this also apply on the sockets layer, or does the sockets operations= (+ > sys calls) are not avoided ? This is assuming that the application uses = regular > sockets to read/write to knis. If you are going to use KNI, there is a copy involved from iovec to RTE mbu= f memory ( assuming you are going to use Ring library for communication bet= ween DPDK application and KNI). I look at KNI as more for control path oper= ation and PMDs for data path.=20 >=20 > Cheers, > Pepe >=20 >=20 > On Wed, Dec 11, 2013 at 7:12 AM, Jose Gavine Cueto > wrote: >=20 > > Hi, > > > > Correct me if I'm wrong, but in a high-level perspective I see that > > kni is providing an option for applications to use their regular interf= aces > (e.g. > > sockets) and abstracts the usage of pmds. > > > > If this is somehow correct, are there any differences with regard to > > performance benefits that can be brought between directly using pmd > > apis and kni ? > > > > I see that kni is easier to use, however at first (no code inspection) > > look, it interfaces with the kernel which might have introduced some > > overhead. > > > > Cheers, > > Pepe > > > > > > -- > > To stop learning is like to stop loving. > > >=20 >=20 >=20 > -- > To stop learning is like to stop loving. Thanks Pash