From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga14.intel.com (mga14.intel.com [192.55.52.115]) by dpdk.org (Postfix) with ESMTP id 336053978 for ; Fri, 4 Nov 2016 13:30:54 +0100 (CET) Received: from fmsmga002.fm.intel.com ([10.253.24.26]) by fmsmga103.fm.intel.com with ESMTP; 04 Nov 2016 05:30:54 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.31,443,1473145200"; d="scan'208";a="1080594964" Received: from fmsmsx106.amr.corp.intel.com ([10.18.124.204]) by fmsmga002.fm.intel.com with ESMTP; 04 Nov 2016 05:30:54 -0700 Received: from fmsmsx119.amr.corp.intel.com (10.18.124.207) by FMSMSX106.amr.corp.intel.com (10.18.124.204) with Microsoft SMTP Server (TLS) id 14.3.248.2; Fri, 4 Nov 2016 05:30:53 -0700 Received: from shsmsx104.ccr.corp.intel.com (10.239.4.70) by FMSMSX119.amr.corp.intel.com (10.18.124.207) with Microsoft SMTP Server (TLS) id 14.3.248.2; Fri, 4 Nov 2016 05:30:53 -0700 Received: from shsmsx103.ccr.corp.intel.com ([169.254.4.139]) by SHSMSX104.ccr.corp.intel.com ([169.254.5.209]) with mapi id 14.03.0248.002; Fri, 4 Nov 2016 20:30:51 +0800 From: "Wang, Zhihong" To: Maxime Coquelin , Yuanhan Liu CC: "stephen@networkplumber.org" , "Pierre Pfister (ppfister)" , "Xie, Huawei" , "dev@dpdk.org" , "vkaplans@redhat.com" , "mst@redhat.com" Thread-Topic: [dpdk-dev] [PATCH v4] vhost: Add indirect descriptors support to the TX path Thread-Index: AQHSJjLIgzIjeGrkS0+qEKh9oEoL36Cr/zyAgAAg9YCAAA7sgIAP4USA//+BDwCAABccgIAAAIiAgAADH4CAAXEIoP//7duAgAVhEfCAAq9+AIABZX6AgAIH/aD//4ajgAAAEyqAABN0pMD//50GgP//aV+A Date: Fri, 4 Nov 2016 12:30:51 +0000 Message-ID: <8F6C2BD409508844A0EFC19955BE09414E7DC66F@SHSMSX103.ccr.corp.intel.com> References: <1474965769-24782-1-git-send-email-maxime.coquelin@redhat.com> <20161017132121.GG16751@yliu-dev.sh.intel.com> <8F6C2BD409508844A0EFC19955BE09414E7D8BDF@SHSMSX103.ccr.corp.intel.com> <20161027103317.GM16751@yliu-dev.sh.intel.com> <0ba8f8c9-2174-b3c1-4f07-f6911bffa6cd@redhat.com> <20161027104621.GN16751@yliu-dev.sh.intel.com> <8F6C2BD409508844A0EFC19955BE09414E7D90C7@SHSMSX103.ccr.corp.intel.com> <88169067-290d-a7bb-ab2c-c9b8ec1b1ded@redhat.com> <8F6C2BD409508844A0EFC19955BE09414E7DA533@SHSMSX103.ccr.corp.intel.com> <8F6C2BD409508844A0EFC19955BE09414E7DC40F@SHSMSX103.ccr.corp.intel.com> <17d285a9-818c-b060-8969-daccb052dc1f@redhat.com> <7e1c8953-db15-f377-cece-85cb7169bb17@redhat.com> <8F6C2BD409508844A0EFC19955BE09414E7DC5B6@SHSMSX103.ccr.corp.intel.com> In-Reply-To: Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-ctpclassification: CTP_IC x-titus-metadata-40: eyJDYXRlZ29yeUxhYmVscyI6IiIsIk1ldGFkYXRhIjp7Im5zIjoiaHR0cDpcL1wvd3d3LnRpdHVzLmNvbVwvbnNcL0ludGVsMyIsImlkIjoiZGZmNzgxYWYtMDg3Yy00YThiLWEzMWMtYzNlOTk3NmJmZTI0IiwicHJvcHMiOlt7Im4iOiJDVFBDbGFzc2lmaWNhdGlvbiIsInZhbHMiOlt7InZhbHVlIjoiQ1RQX0lDIn1dfV19LCJTdWJqZWN0TGFiZWxzIjpbXSwiVE1DVmVyc2lvbiI6IjE1LjkuNi42IiwiVHJ1c3RlZExhYmVsSGFzaCI6IklXOFpZd3pMQkQra1pBOW1qREtpNzdMYzZLMlJkWHA0RkxQQXJkNXk1YjQ9In0= x-originating-ip: [10.239.127.40] Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Subject: Re: [dpdk-dev] [PATCH v4] vhost: Add indirect descriptors support to the TX path 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: Fri, 04 Nov 2016 12:30:55 -0000 > -----Original Message----- > From: Maxime Coquelin [mailto:maxime.coquelin@redhat.com] > Sent: Friday, November 4, 2016 7:23 PM > To: Wang, Zhihong ; Yuanhan Liu > > Cc: stephen@networkplumber.org; Pierre Pfister (ppfister) > ; Xie, Huawei ; dev@dpdk.org; > vkaplans@redhat.com; mst@redhat.com > Subject: Re: [dpdk-dev] [PATCH v4] vhost: Add indirect descriptors suppor= t to the > TX path >=20 >=20 >=20 > >>>> Hi Maxime, > >>>> > >>>> I did a little more macswap test and found out more stuff here: > >>> Thanks for doing more tests. > >>> > >>>> > >>>> 1. I did loopback test on another HSW machine with the same H/W, > >>>> and indirect_desc on and off seems have close perf > >>>> > >>>> 2. So I checked the gcc version: > >>>> > >>>> * Previous: gcc version 6.2.1 20160916 (Fedora 24) > >>>> > >>>> * New: gcc version 5.4.0 20160609 (Ubuntu 16.04.1 LTS) > >>> > >>> On my side, I tested with RHEL7.3: > >>> - gcc (GCC) 4.8.5 20150623 (Red Hat 4.8.5-11) > >>> > >>> It certainly contains some backports from newer GCC versions. > >>> > >>>> > >>>> On previous one indirect_desc has 20% drop > >>>> > >>>> 3. Then I compiled binary on Ubuntu and scp to Fedora, and as > >>>> expected I got the same perf as on Ubuntu, and the perf gap > >>>> disappeared, so gcc is definitely one factor here > >>>> > >>>> 4. Then I use the Ubuntu binary on Fedora for PVP test, then the > >>>> perf gap comes back again and the same with the Fedora binary > >>>> results, indirect_desc causes about 20% drop > >>> > >>> Let me know if I understand correctly: > > > > Yes, and it's hard to breakdown further at this time. > > > > Also we may need to check whether it's caused by certain NIC > > model. Unfortunately I don't have the right setup right now. > > > >>> Loopback test with macswap: > >>> - gcc version 6.2.1 : 20% perf drop > >>> - gcc version 5.4.0 : No drop > >>> > >>> PVP test with macswap: > >>> - gcc version 6.2.1 : 20% perf drop > >>> - gcc version 5.4.0 : 20% perf drop > >> > >> I forgot to ask, did you recompile only host, or both host and guest > >> testmpd's in your test? >=20 > > Both. >=20 > I recompiled testpmd on a Fedora 24 machine using GCC6: > gcc (GCC) 6.1.1 20160621 (Red Hat 6.1.1-3) > Testing loopback with macswap on my Haswell RHEL7.3 machine gives me the > following results: > - indirect on: 7.75Mpps > - indirect off: 7.35Mpps >=20 > Surprisingly, I get better results with indirect on my setup (I > reproduced the tests multiple times). >=20 > Do you have a document explaining the tuning/config you apply to both > the host and the guest (isolation, HT, hugepage size, ...) in your > setup? The setup where it goes wrong: 1. Xeon E5-2699, HT on, turbo off, 1GB hugepage for both host and guest 2. Fortville 40G 3. Fedora 4.7.5-200.fc24.x86_64 4. gcc version 6.2.1 5. 16.11 RC2 for both host and guest 6. PVP, testpmd macswap for both host and guest BTW, I do see indirect_desc gives slightly better performance for loopback in tests on other platforms, but don't know how PVP performs yet. >=20 > Regards, > Maxime