From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga11.intel.com (mga11.intel.com [192.55.52.93]) by dpdk.org (Postfix) with ESMTP id 25242594D for ; Wed, 23 Jul 2014 23:42:28 +0200 (CEST) Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by fmsmga102.fm.intel.com with ESMTP; 23 Jul 2014 14:43:51 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.01,720,1400050800"; d="scan'208";a="566259010" Received: from irsmsx103.ger.corp.intel.com ([163.33.3.157]) by fmsmga001.fm.intel.com with ESMTP; 23 Jul 2014 14:43:50 -0700 Received: from irsmsx110.ger.corp.intel.com (163.33.3.25) by IRSMSX103.ger.corp.intel.com (163.33.3.157) with Microsoft SMTP Server (TLS) id 14.3.123.3; Wed, 23 Jul 2014 22:43:49 +0100 Received: from irsmsx105.ger.corp.intel.com ([169.254.7.76]) by IRSMSX110.ger.corp.intel.com ([163.33.3.25]) with mapi id 14.03.0123.003; Wed, 23 Jul 2014 22:43:49 +0100 From: "Kavanagh, Mark B" To: Antti Kantee , "dev@dpdk.org" Thread-Topic: [dpdk-dev] Performance - linking against DPDK shared vs static libraries Thread-Index: Ac+mjVcpsN1nIv2YR/u0C0/y6Ulg5v///VMA//+bJLA= Date: Wed, 23 Jul 2014 21:43:49 +0000 Message-ID: References: <53CFE4C6.7080506@fixup.fi> In-Reply-To: <53CFE4C6.7080506@fixup.fi> Accept-Language: en-IE, en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [163.33.239.181] Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Subject: Re: [dpdk-dev] Performance - linking against DPDK shared vs static libraries 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: Wed, 23 Jul 2014 21:42:29 -0000 -----Original Message----- From: Antti Kantee [mailto:pooka@fixup.fi] = Sent: Wednesday, July 23, 2014 5:37 PM To: Kavanagh, Mark B; dev@dpdk.org Subject: Re: [dpdk-dev] Performance - linking against DPDK shared vs static= libraries On 23/07/14 15:58, Kavanagh, Mark B wrote: >> Hi, >> >> I build a switching application, which links against DPDK shared librari= es; when I run the application, I see throughput of X. I then build the ap= plication again, except this time I link against DPDK shared libraries, hav= ing modified the application's build parameters appropriately. In this cas= e, I see a performance drop of around .04%, which given the high throughput= of the application is significant. >> >> Is such performance degradation to be expected when using DPDK shared li= braries, and if not, are there any best-known methods for preventing perfor= mance degradation, assuming that I may be constrained to using shared libra= ries going forward? >Do you mean .04% or 4%? I would be more inclined to believe the latter. = >Shared libraries are inherently slower due to indirection from PIC, and be= ing required to use them seems like a silly constraint in the context of hi= gh-performance computing. > - antti It's actually the former, and I agree with your assertion regarding the con= straint! = I take it from your response then that the performance drop when using shar= ed libraries is expected behavior? -------------------------------------------------------------- Intel Shannon Limited Registered in Ireland Registered Office: Collinstown Industrial Park, Leixlip, County Kildare Registered Number: 308263 Business address: Dromore House, East Park, Shannon, Co. Clare This e-mail and any attachments may contain confidential material for the s= ole use of the intended recipient(s). Any review or distribution by others = is strictly prohibited. If you are not the intended recipient, please conta= ct the sender and delete all copies.