From mboxrd@z Thu Jan 1 00:00:00 1970 From: ludo@gnu.org (Ludovic =?utf-8?Q?Court=C3=A8s?=) Subject: Re: Pre-built binaries vs. performance Date: Thu, 01 Feb 2018 18:48:38 +0100 Message-ID: <87zi4slhxl.fsf@gnu.org> References: <87y3ketaf6.fsf@gnu.org> <87inbgmz0y.fsf@inria.fr> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Return-path: Received: from eggs.gnu.org ([2001:4830:134:3::10]:45317) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ehIyb-0008Oo-9E for guix-devel@gnu.org; Thu, 01 Feb 2018 12:48:46 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ehIyX-0002vq-CW for guix-devel@gnu.org; Thu, 01 Feb 2018 12:48:45 -0500 Received: from hera.aquilenet.fr ([185.233.100.1]:57268) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1ehIyX-0002tL-4w for guix-devel@gnu.org; Thu, 01 Feb 2018 12:48:41 -0500 In-Reply-To: (Fis Trivial's message of "Thu, 1 Feb 2018 17:10:14 +0000") List-Id: "Development of GNU Guix and the GNU System distribution." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: guix-devel-bounces+gcggd-guix-devel=m.gmane.org@gnu.org Sender: "Guix-devel" To: Fis Trivial Cc: guix-devel Fis Trivial skribis: > So, we can build packages in a generic way, and then provide optional > dependencies. > In this case, we treat SSE as default dependency and AVX2 as an optional > dependency, let users specify whether they want it or not. > AVX2 need not to be actual packages, it's just an abstraction. > > It's just a thought that we can abstract architecture as part of the > dependency graph. We do that in the form of the =E2=80=9Csystem type=E2=80=9D=E2=80=94=E2=80= =9Cx86_64-linux=E2=80=9D, etc. That captures what=E2=80=99s otherwise not captured in the graph: the architectu= re and the kernel. Someone proposed having, say, =E2=80=9Cx86_64avx2-linux=E2=80=9D, which is = similar in spirit to what you=E2=80=99re proposing, I think. However that=E2=80=99d be inconvenient because every single package in the graph would have to be rebuilt compared to =E2=80=9Cx86_64-linux=E2=80=9D. Also, I don=E2=80=99t see how to make that an _optional_ dependency. Thanks, Ludo=E2=80=99.