From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga04.intel.com (mga04.intel.com [192.55.52.120]) by dpdk.org (Postfix) with ESMTP id ED79FDE0 for ; Tue, 8 Nov 2016 11:51:46 +0100 (CET) Received: from fmsmga002.fm.intel.com ([10.253.24.26]) by fmsmga104.fm.intel.com with ESMTP; 08 Nov 2016 02:51:45 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.31,609,1473145200"; d="scan'208";a="1082201522" Received: from fmsmsx107.amr.corp.intel.com ([10.18.124.205]) by fmsmga002.fm.intel.com with ESMTP; 08 Nov 2016 02:51:45 -0800 Received: from fmsmsx152.amr.corp.intel.com (10.18.125.5) by fmsmsx107.amr.corp.intel.com (10.18.124.205) with Microsoft SMTP Server (TLS) id 14.3.248.2; Tue, 8 Nov 2016 02:51:45 -0800 Received: from shsmsx102.ccr.corp.intel.com (10.239.4.154) by FMSMSX152.amr.corp.intel.com (10.18.125.5) with Microsoft SMTP Server (TLS) id 14.3.248.2; Tue, 8 Nov 2016 02:51:45 -0800 Received: from shsmsx103.ccr.corp.intel.com ([169.254.4.139]) by shsmsx102.ccr.corp.intel.com ([169.254.2.206]) with mapi id 14.03.0248.002; Tue, 8 Nov 2016 18:51:41 +0800 From: "Wang, Zhihong" To: "Wang, Zhihong" , 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+AgACwHQD//3fkAP/40yeA Date: Tue, 8 Nov 2016 10:51:40 +0000 Message-ID: <8F6C2BD409508844A0EFC19955BE09414E7DDD40@SHSMSX103.ccr.corp.intel.com> References: <1474965769-24782-1-git-send-email-maxime.coquelin@redhat.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> <8F6C2BD409508844A0EFC19955BE09414E7DC66F@SHSMSX103.ccr.corp.intel.com> <75d2c094-11e8-99aa-ccb5-60ded04047d7@redhat.com> <8F6C2BD409508844A0EFC19955BE09414E7DC793@SHSMSX103.ccr.corp.intel.com> In-Reply-To: <8F6C2BD409508844A0EFC19955BE09414E7DC793@SHSMSX103.ccr.corp.intel.com> Accept-Language: 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 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: Tue, 08 Nov 2016 10:51:47 -0000 > > > The setup where it goes wrong: > > > 1. Xeon E5-2699, HT on, turbo off, 1GB hugepage for both host and gu= est > > On the Haswell machine (on which I don't have BIOS access), HT is on, > > but I unplug siblings at runtime. > > I also have 1G pages on both sides, and I isolate the cores used by bot= h > > testpmd and vCPUS. > > > > > 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. > > Interesting, other platforms are also Haswell/Broadwell? >=20 > Yes, but with different OS. >=20 > If you don't have the setup I can do more detailed profiling for the > root cause next week, since my platform is the only one right now that > reporting the drop. >=20 >=20 Hi Maxime, I just did some profiling and see much higher L2 miss in vhost dequeue with indirect_desc in my platform, indicates increase of memory access contention. I can keep digging further but might not be able to fix it in time due to limited bandwidth. Hope this helps. Thanks Zhihong =20