From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from szxga03-in.huawei.com (szxga03-in.huawei.com [45.249.212.189]) by dpdk.org (Postfix) with ESMTP id 26F487CCC for ; Wed, 24 May 2017 15:51:53 +0200 (CEST) Received: from 172.30.72.57 (EHLO nkgeml414-hub.china.huawei.com) ([172.30.72.57]) by dggrg03-dlp.huawei.com (MOS 4.4.6-GA FastPath queued) with ESMTP id AOF55482; Wed, 24 May 2017 21:51:43 +0800 (CST) Received: from FRAEML703-CAH.china.huawei.com (10.206.14.34) by nkgeml414-hub.china.huawei.com (10.98.56.75) with Microsoft SMTP Server (TLS) id 14.3.235.1; Wed, 24 May 2017 21:51:41 +0800 Received: from FRAEML521-MBX.china.huawei.com ([169.254.1.104]) by fraeml703-cah.china.huawei.com ([10.206.14.34]) with mapi id 14.03.0301.000; Wed, 24 May 2017 15:51:35 +0200 From: "Avi Cohen (A)" To: "Wiles, Keith" CC: "users@dpdk.org" Thread-Topic: [dpdk-users] OVS vs OVS-DPDK Thread-Index: AdLUZ97jZUqJvxB6SCGIH0ZJhQMn0wAY7dGAAA6IwXA= Date: Wed, 24 May 2017 13:51:36 +0000 Message-ID: References: <365623D9-223D-4A37-ACB7-73599B4E163C@intel.com> In-Reply-To: <365623D9-223D-4A37-ACB7-73599B4E163C@intel.com> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [10.200.202.128] 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=0001.0A020206.59258FEF.00CD, ss=1, re=0.000, recu=0.000, reip=0.000, cl=1, cld=1, fgs=0, ip=169.254.1.104, so=2014-11-16 11:51:01, dmn=2013-03-21 17:37:32 X-Mirapoint-Loop-Id: 54761a354c919399a42fec862659b8d7 Subject: Re: [dpdk-users] OVS vs OVS-DPDK 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: Wed, 24 May 2017 13:51:56 -0000 Thanks Keith for your reply I found out that the bottleneck are the VMs and not the OVS/OVS-DPDK runni= ng in the host. VMs on both setup are unaware to OVS/OVS-DPDK and use their linux IP-stac= k.=20 I found that the performance (e.g. throughput) between VMa - OVS-DPDK - n= etwork - OVS-DPDK - VMb is much better than with standard OVS. I use vhost-user virtio for the OVS-DPDK setup to connect to VM , and vhos= t-net for the standard OVS The reasons for standard OVS poor performance can be for example: 1. number of packet copies in the path NIC - OVS - OS-guest-virtio - Applic= ation on guest 2. interrupt upon receiving a packet 3. # of context-switch / VM-exit etc.. I didn't see any info regarding these potential reasons on the docs. Best Regards avi > -----Original Message----- > From: Wiles, Keith [mailto:keith.wiles@intel.com] > Sent: Wednesday, 24 May, 2017 4:23 PM > To: Avi Cohen (A) > Cc: users@dpdk.org > Subject: Re: [dpdk-users] OVS vs OVS-DPDK >=20 >=20 > > On May 24, 2017, at 3:29 AM, Avi Cohen (A) > wrote: > > > > Hello > > Let me ask it in a different way: > > I want to understand the reasons for the differences in performance be= tween > OVS-DPDK and standard OVS My setup is: ovs/ovs-dpdk is running @ host > communicating with a VM > > > > OVS-DPDK > > 1. packet is received via physical port to the device. > > > > 2.DMA transfer to mempools on huge-pages allocated by dpdk-ovs - in > user-space. > > > > 3. OVS-DPDK copies this packet to the shared-vring of the associated = guest > (shared between ovs-dpdk userspace process and guest) > > > > 4. guest OS copies the packet to userspace application on VM . > > > > Standard OVS > > > > 1. packet is received via physical port to the device. > > > > 2.packet is processed by the OVS and transferred to a virtio device con= nected > to the VM - whar are the additional overhead here ? QEMU processing - > translation , VM exit ?? other ? > > > > 3. guest OS copies the packet to userspace application on VM . > > > > > > Question: what are the additional overhead in the standard OVS that = cause > to poor performance related to the OVS-DPDK setup ? > > I'm not talking about the PMD improvements (OVS-DPDK) running on the > host - but on overhead in the VM context in the standard OVS setup >=20 > The primary reasons are OVS is not using DPDK and OVS is using the Linux > kernel as well :-) >=20 > > > > Best Regards > > avi >=20 > Regards, > Keith