From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from szxga01-in.huawei.com (szxga01-in.huawei.com [45.249.212.187]) by dpdk.org (Postfix) with ESMTP id 9DA797CB3 for ; Mon, 10 Jul 2017 08:49:53 +0200 (CEST) Received: from 172.30.72.54 (EHLO NKGEML413-HUB.china.huawei.com) ([172.30.72.54]) by dggrg01-dlp.huawei.com (MOS 4.4.6-GA FastPath queued) with ESMTP id ARU35649; Mon, 10 Jul 2017 14:49:50 +0800 (CST) Received: from FRAEML702-CAH.china.huawei.com (10.206.14.33) by NKGEML413-HUB.china.huawei.com (10.98.56.74) with Microsoft SMTP Server (TLS) id 14.3.235.1; Mon, 10 Jul 2017 14:49:05 +0800 Received: from FRAEML521-MBX.china.huawei.com ([169.254.1.122]) by fraeml702-cah.china.huawei.com ([10.206.14.33]) with mapi id 14.03.0301.000; Mon, 10 Jul 2017 08:49:00 +0200 From: "Avi Cohen (A)" To: "Tan, Jianfeng" , "dpdk-ovs@lists.01.org" , "users@dpdk.org" Thread-Topic: VIRTIO for containers Thread-Index: AQHS71DYC699Y73ftUG6MPPfZcA7c6I503QggAfGd4CAChbRIIAAqC8AgABYSpA= Date: Mon, 10 Jul 2017 06:49:00 +0000 Message-ID: References: In-Reply-To: Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [10.200.202.183] Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 X-CFilter-Loop: Reflected X-Mirapoint-Virus-RAPID-Raw: score=unknown(0), refid=str=0001.0A020205.59632390.000F, ss=1, re=0.000, recu=0.000, reip=0.000, cl=1, cld=1, fgs=0, ip=169.254.1.122, so=2014-11-16 11:51:01, dmn=2013-03-21 17:37:32 X-Mirapoint-Loop-Id: 93d260bafaaa425b015814967d13f80b Subject: Re: [dpdk-users] VIRTIO for containers X-BeenThere: users@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: DPDK usage discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 10 Jul 2017 06:49:56 -0000 > -----Original Message----- > From: Tan, Jianfeng [mailto:jianfeng.tan@intel.com] > Sent: Monday, 10 July, 2017 6:28 AM > To: Avi Cohen (A); dpdk-ovs@lists.01.org; users@dpdk.org > Subject: RE: VIRTIO for containers > > [Avi Cohen (A)] > > Thanks you Jianfeng > > I've tested it and the performance looks very good compared to native o= vs. > > I have 1 more question: > > You wrote " there's a vhost kthread to push the data out to user space > > " - Is that mean a copy from userspace to kernel (and viceversa) or > > there is a zero-copy mmap like in AF_PACKET which handles TX/RX rings = in > userspace ? > > Best Regards > > avi >=20 > So far it needs data copy at least from kernel to user path; there's an > experimental feature, named experimental_zcopytx, to avoid data copy, but > not very useful due to the implementation limitation. [Avi Cohen (A)]=20 Thanks Jianfeng The penalty here that this vhost-kthread consumes very much CPU on a high = throughput scenario - more than 80% CPU on ~ 10Gbps throughput And this is in addition to the 100% CPU of the PMD threads Also when PMD threads can be shared between multiple containers - the vhost= -kthread is per container. Best Regards avi >=20 > Packet mmap (similar to AF_PACKET) is exactly the direction we were > discussing for the further optimization. Plus, an optimized vhost thread > model (current thread model is: one thread for one rx-tx queue pair) is a= lso > considered. >=20 > Thanks, > Jianfeng >=20