From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga03.intel.com (mga03.intel.com [134.134.136.65]) by dpdk.org (Postfix) with ESMTP id 668B11B3C3 for ; Thu, 2 Nov 2017 11:58:44 +0100 (CET) Received: from fmsmga004.fm.intel.com ([10.253.24.48]) by orsmga103.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 02 Nov 2017 03:58:43 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.44,333,1505804400"; d="scan'208";a="331025282" Received: from fmsmsx104.amr.corp.intel.com ([10.18.124.202]) by fmsmga004.fm.intel.com with ESMTP; 02 Nov 2017 03:58:42 -0700 Received: from fmsmsx155.amr.corp.intel.com (10.18.116.71) by fmsmsx104.amr.corp.intel.com (10.18.124.202) with Microsoft SMTP Server (TLS) id 14.3.319.2; Thu, 2 Nov 2017 03:58:42 -0700 Received: from shsmsx152.ccr.corp.intel.com (10.239.6.52) by FMSMSX155.amr.corp.intel.com (10.18.116.71) with Microsoft SMTP Server (TLS) id 14.3.319.2; Thu, 2 Nov 2017 03:58:42 -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, 2 Nov 2017 18:58:40 +0800 From: "Li, Xiaoyun" To: Thomas Monjalon , "Wang, Zhihong" CC: "dev@dpdk.org" , "Richardson, Bruce" , "Ananyev, Konstantin" , "Lu, Wenzhuo" , "Zhang, Helin" , "ophirmu@mellanox.com" Thread-Topic: [dpdk-dev] [PATCH v8 1/3] eal/x86: run-time dispatch over memcpy Thread-Index: AQHTRAIprgY4BVeLI0+Q0HvX97iHcaLoDmwAgADN1xCAAE2qAIABU4GQ///D5QCAAJH3wP//iH4AgACJLtD//35agAABBKoAADE0GyABBw7bEP//iSeAgAZg+ICABmM1gIAABiIA//95EnA= Date: Thu, 2 Nov 2017 10:58:39 +0000 Message-ID: References: <1507206794-79941-1-git-send-email-xiaoyun.li@intel.com> <6811801.9Gdy4CqsrT@xps> <8F6C2BD409508844A0EFC19955BE0941513593EB@SHSMSX103.ccr.corp.intel.com> <2027509.fDzOy6Rher@xps> In-Reply-To: <2027509.fDzOy6Rher@xps> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: dlp-product: dlpe-windows dlp-version: 11.0.0.116 dlp-reaction: no-action x-ctpclassification: CTP_IC x-titus-metadata-40: eyJDYXRlZ29yeUxhYmVscyI6IiIsIk1ldGFkYXRhIjp7Im5zIjoiaHR0cDpcL1wvd3d3LnRpdHVzLmNvbVwvbnNcL0ludGVsMyIsImlkIjoiNTliMGI4MDUtMjI3MS00MWIzLTgyNzItYzc5YjZjNjE3MDJlIiwicHJvcHMiOlt7Im4iOiJDVFBDbGFzc2lmaWNhdGlvbiIsInZhbHMiOlt7InZhbHVlIjoiQ1RQX0lDIn1dfV19LCJTdWJqZWN0TGFiZWxzIjpbXSwiVE1DVmVyc2lvbiI6IjE2LjUuOS4zIiwiVHJ1c3RlZExhYmVsSGFzaCI6ImR0OFZONzJcL1VuZTZxOHl2ekpYOU02UlBiV3VhYmhUM2g2ZUtlNDB5S3BzPSJ9 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 List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 02 Nov 2017 10:58:45 -0000 > -----Original Message----- > From: Thomas Monjalon [mailto:thomas@monjalon.net] > Sent: Thursday, November 2, 2017 18:45 > To: Wang, Zhihong ; Li, Xiaoyun > > Cc: dev@dpdk.org; Richardson, Bruce ; > Ananyev, Konstantin ; Lu, Wenzhuo > ; Zhang, Helin ; > ophirmu@mellanox.com > Subject: Re: [dpdk-dev] [PATCH v8 1/3] eal/x86: run-time dispatch over > memcpy >=20 > 02/11/2017 11:22, Wang, Zhihong: > > > I don't know what is creating this drop exactly. > > > When doing different tests on different environments, we do not see > > > this drop. > > > If nobody else can see such issue, I guess we can ignore it. > > > > Hi Thomas, Xiaoyun, > > > > With this patch (commit 84cc318424d49372dd2a5fbf3cf84426bf95acce) I > > see more than 20% performance drop in vhost loopback test with testpmd > > macswap for 256 bytes packets, which means it impacts actual > > vSwitching performance. > > > > Suggest we fix it or revert it for this release. >=20 > I think we need more numbers to take a decision. > What is the benefit of this patch? In which use-cases? The benefit is that if compile it on a lower platform (such as only suppor= ts SSE), when it run on higher platforms (such as AVX2 or AVX512). It would still ca= n get ISA benefit (AVX2). User case seems to be that some customers want it in cloud environment and = don't want to compile on all platforms. > What are the drawbacks? In which use-cases? The drawback is perf drop. So far, see lot of drop in mellanox case and vho= st case. Should I send the revert patch or you revert it directly? >=20 > Please, it is a call to test performance with and without this patch in m= ore > environments (CPU, packet size, applications).