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 0C531B37C for ; Thu, 28 Aug 2014 11:18:22 +0200 (CEST) Received: from orsmga001.jf.intel.com ([10.7.209.18]) by orsmga102.jf.intel.com with ESMTP; 28 Aug 2014 02:16:30 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.04,417,1406617200"; d="scan'208";a="564656190" Received: from irsmsx101.ger.corp.intel.com ([163.33.3.153]) by orsmga001.jf.intel.com with ESMTP; 28 Aug 2014 02:22:28 -0700 Received: from irsmsx155.ger.corp.intel.com (163.33.192.3) by IRSMSX101.ger.corp.intel.com (163.33.3.153) with Microsoft SMTP Server (TLS) id 14.3.195.1; Thu, 28 Aug 2014 10:22:28 +0100 Received: from irsmsx103.ger.corp.intel.com ([169.254.3.112]) by IRSMSX155.ger.corp.intel.com ([169.254.14.85]) with mapi id 14.03.0195.001; Thu, 28 Aug 2014 10:22:27 +0100 From: "Richardson, Bruce" To: Thomas Monjalon Thread-Topic: [dpdk-dev] next releases Thread-Index: AQHPwIhBDWUWJgaSGUiCZC+tdifuR5vkoCKAgAEPAzD///2hgIAAE2iA Date: Thu, 28 Aug 2014 09:22:27 +0000 Message-ID: <59AF69C657FD0841A61C55336867B5B0343ECBD2@IRSMSX103.ger.corp.intel.com> References: <1598074.SMl35i2x6y@xps13> <53FE0FA5.8020900@tilera.com> <59AF69C657FD0841A61C55336867B5B0343ECAF0@IRSMSX103.ger.corp.intel.com> <2353283.PtiVvKdYNr@xps13> In-Reply-To: <2353283.PtiVvKdYNr@xps13> Accept-Language: en-GB, 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" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Cc: "dev@dpdk.org" Subject: Re: [dpdk-dev] next releases 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: Thu, 28 Aug 2014 09:18:23 -0000 > -----Original Message----- > From: Thomas Monjalon [mailto:thomas.monjalon@6wind.com] > Sent: Thursday, August 28, 2014 10:06 AM > To: Richardson, Bruce > Cc: Cyril Chemparathy; dev@dpdk.org > Subject: Re: [dpdk-dev] next releases >=20 > 2014-08-28 08:41, Richardson, Bruce: > > As for rte_rdtsc_precise, I'm not sure about its origins, but I'm > > surprised to see that it does not correspond to the rdtscp instruction. > > Can anyone else comment on this one? I would assume it's designed > > to be used to get more accurate measurements of smaller blocks of > > code that we want to benchmark, since rdtsc works best when timing > > larger blocks (in terms of cycle counts, that is, not source lines :-) = ). >=20 > The good thing with git history (and well written commit logs) is that > we can easily get such answer: > http://dpdk.org/browse/dpdk/commit/?id=3D3314648f83c3dc06d7d9a Indeed! I had mistakenly assumed that the function was older than the dpdk.= org history. My bad on that one, and thanks for the link. :-) >=20 > Bruce, do you know how rdtscp is supported across Intel processors? Sorry, no I don't, and the instruction set manuals only say to check the re= levant cpuid bit to see if it's supported. :-(. If the existing code works = ok, there is probably no compelling reason to look to change it though. >=20 > -- > Thomas