From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga09.intel.com (mga09.intel.com [134.134.136.24]) by dpdk.org (Postfix) with ESMTP id E50BEFFA for ; Thu, 31 Aug 2017 03:24:45 +0200 (CEST) Received: from fmsmga004.fm.intel.com ([10.253.24.48]) by orsmga102.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 30 Aug 2017 18:24:44 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.41,451,1498546800"; d="scan'208";a="306367448" Received: from fmsmsx106.amr.corp.intel.com ([10.18.124.204]) by fmsmga004.fm.intel.com with ESMTP; 30 Aug 2017 18:24:44 -0700 Received: from fmsmsx121.amr.corp.intel.com (10.18.125.36) by FMSMSX106.amr.corp.intel.com (10.18.124.204) with Microsoft SMTP Server (TLS) id 14.3.319.2; Wed, 30 Aug 2017 18:24:44 -0700 Received: from shsmsx151.ccr.corp.intel.com (10.239.6.50) by fmsmsx121.amr.corp.intel.com (10.18.125.36) with Microsoft SMTP Server (TLS) id 14.3.319.2; Wed, 30 Aug 2017 18:24:44 -0700 Received: from shsmsx102.ccr.corp.intel.com ([169.254.2.39]) by SHSMSX151.ccr.corp.intel.com ([169.254.3.98]) with mapi id 14.03.0319.002; Thu, 31 Aug 2017 09:23:52 +0800 From: "Lu, Wenzhuo" To: Stephen Hemminger , "Li, Xiaoyun" CC: "Richardson, Bruce" , "dev@dpdk.org" , "Wang, Zhihong" , "Zhang, Qi Z" Thread-Topic: [dpdk-dev] [PATCH 1/3] eal/x86: run-time dispatch over memcpy Thread-Index: AQHTHUbgSxBQ6olark6qfBV0AOXa7qKcsx0AgAEBP+A= Date: Thu, 31 Aug 2017 01:23:52 +0000 Message-ID: <6A0DE07E22DDAD4C9103DF62FEBC09093B6A2D25@shsmsx102.ccr.corp.intel.com> References: <1503626773-184682-1-git-send-email-xiaoyun.li@intel.com> <1503626773-184682-2-git-send-email-xiaoyun.li@intel.com> <20170830110040.20b037e6@xeon-e3> In-Reply-To: <20170830110040.20b037e6@xeon-e3> 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 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, 31 Aug 2017 01:24:46 -0000 Hi Stephen, > -----Original Message----- > From: Stephen Hemminger [mailto:stephen@networkplumber.org] > Sent: Thursday, August 31, 2017 2:01 AM > To: Li, Xiaoyun > Cc: Richardson, Bruce ; dev@dpdk.org; Lu, > Wenzhuo ; Wang, Zhihong > ; Zhang, Qi Z > Subject: Re: [dpdk-dev] [PATCH 1/3] eal/x86: run-time dispatch over memcp= y >=20 > On Fri, 25 Aug 2017 10:06:11 +0800 > Xiaoyun Li wrote: >=20 > > This patch dynamically selects functions of memcpy at run-time based > > on CPU flags that current machine supports. This patch uses function > > pointers which are bind to the relative functions at constrctor time. > > To make AVX512 instructions pass compilation, enable the switch in > > makefile. > > > > Signed-off-by: Xiaoyun Li >=20 > Recent versions of GCC also have better ways to handle this. I think the assumption of using the instructions is that we believe we can = do better than the compiler. If it turns out not, maybe we need to change t= he instructions back to C. But it's another story.