From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: <cunming.liang@intel.com> Received: from mga09.intel.com (mga09.intel.com [134.134.136.24]) by dpdk.org (Postfix) with ESMTP id 8F7AC960E for <dev@dpdk.org>; Tue, 23 Dec 2014 10:52:05 +0100 (CET) Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by orsmga102.jf.intel.com with ESMTP; 23 Dec 2014 01:50:10 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.07,630,1413270000"; d="scan'208";a="641845129" Received: from pgsmsx104.gar.corp.intel.com ([10.221.44.91]) by fmsmga001.fm.intel.com with ESMTP; 23 Dec 2014 01:52:01 -0800 Received: from kmsmsx154.gar.corp.intel.com (172.21.73.14) by PGSMSX104.gar.corp.intel.com (10.221.44.91) with Microsoft SMTP Server (TLS) id 14.3.195.1; Tue, 23 Dec 2014 17:52:00 +0800 Received: from shsmsx151.ccr.corp.intel.com (10.239.6.50) by KMSMSX154.gar.corp.intel.com (172.21.73.14) with Microsoft SMTP Server (TLS) id 14.3.195.1; Tue, 23 Dec 2014 17:51:59 +0800 Received: from shsmsx102.ccr.corp.intel.com ([169.254.2.216]) by SHSMSX151.ccr.corp.intel.com ([169.254.3.67]) with mapi id 14.03.0195.001; Tue, 23 Dec 2014 17:51:59 +0800 From: "Liang, Cunming" <cunming.liang@intel.com> To: Stephen Hemminger <stephen@networkplumber.org>, "Richardson, Bruce" <bruce.richardson@intel.com> Thread-Topic: [dpdk-dev] [RFC PATCH 0/7] support multi-phtread per lcore Thread-Index: AQHQFObgfmq64AgbV0e+OTw3KgLpHZyJoZWAgAGfW9CABL60AIAAkFJwgAQ6C4CAAV5A0IAADfiAgASiO/CAAA/UgIAAkhMAgAGGYrA= Date: Tue, 23 Dec 2014 09:51:58 +0000 Message-ID: <D0158A423229094DA7ABF71CF2FA0DA31188F9AD@shsmsx102.ccr.corp.intel.com> References: <1418263490-21088-1-git-send-email-cunming.liang@intel.com> <7C4248CAE043B144B1CD242D275626532FE15298@IRSMSX104.ger.corp.intel.com> <D0158A423229094DA7ABF71CF2FA0DA31188B881@shsmsx102.ccr.corp.intel.com> <7C4248CAE043B144B1CD242D275626532FE232BA@IRSMSX104.ger.corp.intel.com> <D0158A423229094DA7ABF71CF2FA0DA31188C928@shsmsx102.ccr.corp.intel.com> <7C4248CAE043B144B1CD242D275626532FE27C3B@IRSMSX104.ger.corp.intel.com> <D0158A423229094DA7ABF71CF2FA0DA31188E454@shsmsx102.ccr.corp.intel.com> <20141219100342.GA3848@bricha3-MOBL3> <D0158A423229094DA7ABF71CF2FA0DA31188EF9F@shsmsx102.ccr.corp.intel.com> <20141222094603.GA1768@bricha3-MOBL3> <20141222102852.7e6d5e81@urahara> In-Reply-To: <20141222102852.7e6d5e81@urahara> Accept-Language: zh-CN, 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 Cc: "dev@dpdk.org" <dev@dpdk.org> Subject: Re: [dpdk-dev] [RFC PATCH 0/7] support multi-phtread per lcore X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: patches and discussions about DPDK <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: Tue, 23 Dec 2014 09:52:06 -0000 > -----Original Message----- > From: Stephen Hemminger [mailto:stephen@networkplumber.org] > Sent: Tuesday, December 23, 2014 2:29 AM > To: Richardson, Bruce > Cc: Liang, Cunming; dev@dpdk.org > Subject: Re: [dpdk-dev] [RFC PATCH 0/7] support multi-phtread per lcore >=20 > On Mon, 22 Dec 2014 09:46:03 +0000 > Bruce Richardson <bruce.richardson@intel.com> wrote: >=20 > > On Mon, Dec 22, 2014 at 01:51:27AM +0000, Liang, Cunming wrote: > > > ... > > > > I'm conflicted on this one. However, I think far more applications = would be > > > > broken > > > > to start having to use thread_id in place of an lcore_id than would= be > broken > > > > by having the lcore_id no longer actually correspond to a core. > > > > I'm actually struggling to come up with a large number of scenarios= where > it's > > > > important to an app to determine the cpu it's running on, compared = to the > large > > > > number of cases where you need to have a data-structure per thread.= In > DPDK > > > > libs > > > > alone, you see this assumption that lcore_id =3D=3D thread_id a lar= ge number > of > > > > times. > > > > > > > > Despite the slight logical inconsistency, I think it's better to av= oid > introducing > > > > a thread-id and continue having lcore_id representing a unique thre= ad. > > > > > > > > /Bruce > > > > > > Ok, I understand it. > > > I list the implicit meaning if using lcore_id representing the unique= thread. > > > 1). When lcore_id less than RTE_MAX_LCORE, it still represents the lo= gical > core id. > > > 2). When lcore_id large equal than RTE_MAX_LCORE, it represents an un= ique > id for thread. > > > 3). Most of APIs(except rte_lcore_id()) in rte_lcore.h suggest to be = used only > in CASE 1) > > > 4). rte_lcore_id() can be used in CASE 2), but the return value no ma= tter > represent a logical core id. > > > > > > If most of us feel it's acceptable, I'll prepare for the RFC v2 base = on this > conclusion. > > > > > > /Cunming > > > > Sorry, I don't like that suggestion either, as having lcore_id values g= reater > > than RTE_MAX_LCORE is terrible, as how will people know how to dimensio= n > arrays > > to be indexes by lcore id? Given the choice, if we are not going to jus= t use > > lcore_id as a generic thread id, which is always between 0 and > RTE_MAX_LCORE > > we can look to define a new thread_id variable to hold that. However, i= t should > > have a bounded range. > > From an ease-of-porting perspective, I still think that the simplest op= tion is to > > use the existing lcore_id and accept the fact that it's now a thread id= rather > > than an actual physical lcore. Question is, is would that cause us lots= of issues > > in the future? > > > > /Bruce >=20 > The current rte_lcore_id() has different meaning the thread. Your proposa= l will > break code that uses lcore_id to do per-cpu statistics and the lcore_conf= ig > code in the samples. > q [Liang, Cunming] +1.=20