From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga01.intel.com (mga01.intel.com [192.55.52.88]) by dpdk.org (Postfix) with ESMTP id ABB1F58D9 for ; Tue, 15 Jul 2014 17:40:41 +0200 (CEST) Received: from fmsmga002.fm.intel.com ([10.253.24.26]) by fmsmga101.fm.intel.com with ESMTP; 15 Jul 2014 08:40:58 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.01,666,1400050800"; d="scan'208";a="570157648" Received: from fmsmsx108.amr.corp.intel.com ([10.19.9.228]) by fmsmga002.fm.intel.com with ESMTP; 15 Jul 2014 08:40:58 -0700 Received: from fmsmsx114.amr.corp.intel.com (10.18.116.8) by FMSMSX108.amr.corp.intel.com (10.19.9.228) with Microsoft SMTP Server (TLS) id 14.3.123.3; Tue, 15 Jul 2014 08:40:58 -0700 Received: from shsmsx152.ccr.corp.intel.com (10.239.6.52) by FMSMSX114.amr.corp.intel.com (10.18.116.8) with Microsoft SMTP Server (TLS) id 14.3.123.3; Tue, 15 Jul 2014 08:40:58 -0700 Received: from shsmsx103.ccr.corp.intel.com ([169.254.4.26]) by SHSMSX152.ccr.corp.intel.com ([169.254.6.36]) with mapi id 14.03.0123.003; Tue, 15 Jul 2014 23:40:56 +0800 From: "Zhou, Danny" To: "John W. Linville" , Neil Horman Thread-Topic: [dpdk-dev] [PATCH v2] librte_pmd_packet: add PMD for AF_PACKET-based virtual devices Thread-Index: AQHPn5Gwvcd4A0wcTkeObxakesCY6JugPv4wgABJUgCAABzngIAAoGOA Date: Tue, 15 Jul 2014 15:40:56 +0000 Message-ID: References: <1405024369-30058-1-git-send-email-linville@tuxdriver.com> <1405362290-6753-1-git-send-email-linville@tuxdriver.com> <20140715121743.GA14273@localhost.localdomain> <20140715140111.GA26012@tuxdriver.com> In-Reply-To: <20140715140111.GA26012@tuxdriver.com> Accept-Language: zh-CN, 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 v2] librte_pmd_packet: add PMD for AF_PACKET-based virtual devices 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: Tue, 15 Jul 2014 15:40:42 -0000 > -----Original Message----- > From: John W. Linville [mailto:linville@tuxdriver.com] > Sent: Tuesday, July 15, 2014 10:01 PM > To: Neil Horman > Cc: Zhou, Danny; dev@dpdk.org > Subject: Re: [dpdk-dev] [PATCH v2] librte_pmd_packet: add PMD for > AF_PACKET-based virtual devices >=20 > On Tue, Jul 15, 2014 at 08:17:44AM -0400, Neil Horman wrote: > > On Tue, Jul 15, 2014 at 12:15:49AM +0000, Zhou, Danny wrote: > > > According to my performance measurement results for 64B small > > > packet, 1 queue perf. is better than 16 queues (1.35M pps vs. 0.93M > > > pps) which make sense to me as for 16 queues case more CPU cycles > > > (16 queues' 87% vs. 1 queue' 80%) in kernel land needed for > > > NAPI-enabled ixgbe driver to switch between polling and interrupt > > > modes in order to service per-queue rx interrupts, so more context > > > switch overhead involved. Also, since the > > > eth_packet_rx/eth_packet_tx routines involves in two memory copies > > > between DPDK mbuf and pbuf for each packet, it can hardly achieve > > > high performance unless packet are directly DMA to mbuf which needs i= xgbe > driver to support. > > > > I thought 16 queues would be spread out between as many cpus as you > > had though, obviating the need for context switches, no? >=20 > I think Danny is testing the single CPU case. Having more queues than CP= Us > probably does not provide any benefit. >=20 > It would be cool to hack the DPDK memory management to work directly out = of the > mmap'ed AF_PACKET buffers. But at this point I don't have enough knowled= ge of > DPDK internals to know if that is at all reasonable... >=20 > John >=20 > P.S. Danny, have you run any performance tests on the PCAP driver? No, I do not have PCAP driver performance results in hand. But I remember i= t is less than 1M pps for 64B. >=20 > -- > John W. Linville Someday the world will need a hero, and you > linville@tuxdriver.com might be all we have. Be ready.