From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from dpdk.org (dpdk.org [92.243.14.124]) by inbox.dpdk.org (Postfix) with ESMTP id BDCC2A04DB; Tue, 17 Nov 2020 10:15:34 +0100 (CET) Received: from [92.243.14.124] (localhost [127.0.0.1]) by dpdk.org (Postfix) with ESMTP id 0E97C58C4; Tue, 17 Nov 2020 10:15:32 +0100 (CET) Received: from mga03.intel.com (mga03.intel.com [134.134.136.65]) by dpdk.org (Postfix) with ESMTP id 773044C90 for ; Tue, 17 Nov 2020 10:15:30 +0100 (CET) IronPort-SDR: D/0wal/M+GKDDZdWemYdIktLq/x/P1D3qoK2JxAOQih2L472O8ZFbwdM8KKP64lxS5cMfEL4E1 yxvisLCHMw6A== X-IronPort-AV: E=McAfee;i="6000,8403,9807"; a="170991549" X-IronPort-AV: E=Sophos;i="5.77,485,1596524400"; d="scan'208";a="170991549" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga005.jf.intel.com ([10.7.209.41]) by orsmga103.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 17 Nov 2020 01:15:28 -0800 IronPort-SDR: zv1Bjm9A+ZtUj7HDzJyIOpcDOo/X/MlIkNHma3vBY1lpHTpzFh7Ly3H5+GeBagEzhq1y5ekKsG ryo/+4ju05QQ== X-IronPort-AV: E=Sophos;i="5.77,485,1596524400"; d="scan'208";a="543964210" Received: from rkeeling-mobl2.ger.corp.intel.com (HELO bricha3-MOBL.ger.corp.intel.com) ([10.251.83.1]) by orsmga005-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-SHA; 17 Nov 2020 01:15:22 -0800 Date: Tue, 17 Nov 2020 09:15:18 +0000 From: Bruce Richardson To: Thomas Monjalon Cc: Juraj =?utf-8?Q?Linke=C5=A1?= , Honnappa Nagarahalli , Ruifeng Wang , Phil Yang , "vcchunga@amazon.com" , Dharmik Thakkar , "jerinjacobk@gmail.com" , "hemant.agrawal@nxp.com" , "Ajit Khaparde (ajit.khaparde@broadcom.com)" , "ferruh.yigit@intel.com" , "dev@dpdk.org" , "david.marchand@redhat.com" , nd Message-ID: <20201117091518.GA1522@bricha3-MOBL.ger.corp.intel.com> References: <1605267483-13167-1-git-send-email-juraj.linkes@pantheon.tech> <4553269.LkjHWWX2LK@thomas> <2366611.vJsMBebm0t@thomas> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <2366611.vJsMBebm0t@thomas> Subject: Re: [dpdk-dev] [PATCH v12 01/14] build: alias default build as generic 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: , Errors-To: dev-bounces@dpdk.org Sender: "dev" On Tue, Nov 17, 2020 at 08:49:45AM +0100, Thomas Monjalon wrote: > 17/11/2020 03:46, Honnappa Nagarahalli: > > > > > > > > > > 16/11/2020 17:16, Bruce Richardson: > > > > On Mon, Nov 16, 2020 at 03:50:31PM +0000, Juraj Linkeš wrote: > > > > > From: Thomas Monjalon > > > > > > 13/11/2020 15:31, Juraj Linkeš: > > > > > > > The current machine='default' build name is not descriptive. The > > > > > > > actual default build is machine='native'. Add an alternative > > > > > > > string which does the same build and better describes what we're > > > building: > > > > > > > machine='generic'. Leave machine='default' for backwards > > > compatibility. > > > > > > > > > > > > What? > > > > > > > > > > > > "generic" means... nothing. > > > > > > > > > > > > > > > > An absence of anything means nothing. Generic means "characteristic of > > > or relating to a class or group of things; not specific", which is pretty much > > > what we're looking for. > > > > > > > > > > > "default" should be the most common set of options to make a build > > > > > > work everywhere. > > > > > > > > > > What we want is a value of machine that would "be the most common > > > set of options to make a build work everywhere" and using the above > > > definition of generic, it fits very well. > > > > > The reason I said the actual default build is machine='native' is because > > > that's how the machine option is defined in meson_options.txt. It follows > > > from what default actually means - "a preselected option adopted by a > > > computer program or other mechanism when no alternative is specified by > > > the user or programmer". Default then means no user input, which means > > > machine='native', which means the default build is the default build. > > > > > > > > > > What ""default" should mean" looks like an attempt at redefining what > > > the word actually means and leads to confusion, in my experience. Hence an > > > attempt to remove the potential ambiguity. > > > > > > > > > > > > > I would tend to agree that "generic" is probably a better term than > > > > "default" for what we use it for here in the config. > > > > > > In the past, we had a different definition with make config. > > > I am just trying to be consistent. > > > Even with meson, default means "minimal CPU instructions". > > > > > > Example in devtools/test-meson-builds.sh: > > > "test compilation with minimal x86 instruction set" > > > is called build-x86-default. > > > > > > In config/meson.build: > > > " > > > machine type 'default' is special, it defaults to the per arch agreed common > > > minimal baseline needed for DPDK. > > > That might not be the most optimized, but the most portable version while > > > still being able to support the CPU features required for DPDK. > > > This can be bumped up by the DPDK project, but it can never be an invariant > > > like 'native' > > > " > > > > > > So, why this definition is called "generic" in meson Arm config? > > The explanation above is for a build type 'default'. Whereas meson by default builds for build type 'native'. Also when you look at the config/arm/meson.build the word 'default' was used where it was not related to the build type default. It created lot of confusion. > > > > From the dictionary 'default' - "a preselected option adopted by a computer program or other mechanism when no alternative is specified by the user or programmer." But, if one had to do build of type default, they have to mention -Dmachine=default. If nothing is mentioned, it is a build type 'native', which does not go along with the definition of 'default'. > > > > But for 'generic' - "characteristic of or relating to a class or group of things; not specific". IMO, it better suits the explanation you have provided above. So, separating this machine type to 'generic' to cover the same definition makes more sense. > > > > However, 'default' is still supported for backward compatibility. > > So? Are you going to change the DPDK definitions we had for years? > I think we should, or at least support "generic" alongside it. Using the term "default" for something that is not the default is confusing. It's also not a good description of what the result is, since it's a generic binary for the architecture, rather than a "default" one for the architecture. /Bruce