From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: <xiaoyun.li@intel.com> Received: from mga05.intel.com (mga05.intel.com [192.55.52.43]) by dpdk.org (Postfix) with ESMTP id 7F57927D for <dev@dpdk.org>; Thu, 19 Oct 2017 04:45:30 +0200 (CEST) Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by fmsmga105.fm.intel.com with ESMTP; 18 Oct 2017 19:45:29 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.43,399,1503385200"; d="scan'208";a="164324917" Received: from fmsmsx105.amr.corp.intel.com ([10.18.124.203]) by fmsmga005.fm.intel.com with ESMTP; 18 Oct 2017 19:45:29 -0700 Received: from fmsmsx115.amr.corp.intel.com (10.18.116.19) by FMSMSX105.amr.corp.intel.com (10.18.124.203) with Microsoft SMTP Server (TLS) id 14.3.319.2; Wed, 18 Oct 2017 19:45:29 -0700 Received: from shsmsx152.ccr.corp.intel.com (10.239.6.52) by fmsmsx115.amr.corp.intel.com (10.18.116.19) with Microsoft SMTP Server (TLS) id 14.3.319.2; Wed, 18 Oct 2017 19:45:28 -0700 Received: from shsmsx101.ccr.corp.intel.com ([169.254.1.159]) by SHSMSX152.ccr.corp.intel.com ([169.254.6.93]) with mapi id 14.03.0319.002; Thu, 19 Oct 2017 10:45:26 +0800 From: "Li, Xiaoyun" <xiaoyun.li@intel.com> To: Thomas Monjalon <thomas@monjalon.net>, "Ananyev, Konstantin" <konstantin.ananyev@intel.com>, "Richardson, Bruce" <bruce.richardson@intel.com> CC: "dev@dpdk.org" <dev@dpdk.org>, "Lu, Wenzhuo" <wenzhuo.lu@intel.com>, "Zhang, Helin" <helin.zhang@intel.com>, "ophirmu@mellanox.com" <ophirmu@mellanox.com> Thread-Topic: [dpdk-dev] [PATCH v8 1/3] eal/x86: run-time dispatch over memcpy Thread-Index: AQHTRAIprgY4BVeLI0+Q0HvX97iHcaLoDmwAgADN1xCAAE2qAIABU4GQ Date: Thu, 19 Oct 2017 02:45:26 +0000 Message-ID: <B9E724F4CB7543449049E7AE7669D82F47FD6D@SHSMSX101.ccr.corp.intel.com> References: <1507206794-79941-1-git-send-email-xiaoyun.li@intel.com> <1507885309-165144-1-git-send-email-xiaoyun.li@intel.com> <1507885309-165144-2-git-send-email-xiaoyun.li@intel.com> <4482530.zMd2RtzCvC@xps> <B9E724F4CB7543449049E7AE7669D82F47F757@SHSMSX101.ccr.corp.intel.com> <B9E724F4CB7543449049E7AE7669D82F47F814@SHSMSX101.ccr.corp.intel.com> In-Reply-To: <B9E724F4CB7543449049E7AE7669D82F47F814@SHSMSX101.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 v8 1/3] eal/x86: run-time dispatch over memcpy X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: DPDK patches and discussions <dev.dpdk.org> List-Unsubscribe: <http://dpdk.org/ml/options/dev>, <mailto:dev-request@dpdk.org?subject=unsubscribe> List-Archive: <http://dpdk.org/ml/archives/dev/> List-Post: <mailto:dev@dpdk.org> List-Help: <mailto:dev-request@dpdk.org?subject=help> List-Subscribe: <http://dpdk.org/ml/listinfo/dev>, <mailto:dev-request@dpdk.org?subject=subscribe> X-List-Received-Date: Thu, 19 Oct 2017 02:45:30 -0000 Hi > > > > > > The significant change of this patch is to call a function pointer > > > for packet size > 128 (RTE_X86_MEMCPY_THRESH). > > The perf drop is due to function call replacing inline. > > > > > Please could you provide some benchmark numbers? > > I ran memcpy_perf_test which would show the time cost of memcpy. I ran > > it on broadwell with sse and avx2. > > But I just draw pictures and looked at the trend not computed the > > exact percentage. Sorry about that. > > The picture shows results of copy size of 2, 4, 6, 8, 9, 12, 16, 32, > > 64, 128, 192, 256, 320, 384, 448, 512, 768, 1024, 1518, 1522, 1536, > > 1600, 2048, 2560, 3072, 3584, 4096, 4608, 5120, 5632, 6144, 6656, 7168, > 7680, 8192. > > In my test, the size grows, the drop degrades. (Using copy time > > indicates the > > perf.) From the trend picture, when the size is smaller than 128 > > bytes, the perf drops a lot, almost 50%. And above 128 bytes, it > > approaches the original dpdk. > > I computed it right now, it shows that when greater than 128 bytes and > > smaller than 1024 bytes, the perf drops about 15%. When above 1024 > > bytes, the perf drops about 4%. > > > > > From a test done at Mellanox, there might be a performance > > > degradation of about 15% in testpmd txonly with AVX2. >=20 I did tests on X710, XXV710, X540 and MT27710 but didn't see performance de= gradation. I used command "./x86_64-native-linuxapp-gcc/app/testpmd -c 0xf -n 4 -- -I"= and set fwd txonly.=20 I tested it on v17.11-rc1, then revert my patch and tested it again. Show port stats all and see the throughput pps. But the results are similar= and no drop. Did I miss something? > Another thing, I will test testpmd txonly with intel nics and mellanox th= ese > days. > And try adjusting the RTE_X86_MEMCPY_THRESH to see if there is any > improvement. >=20 > > > Is there someone else seeing a performance degradation?