From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,UNPARSEABLE_RELAY autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id A2D94C04EB8 for ; Fri, 30 Nov 2018 23:26:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6950720673 for ; Fri, 30 Nov 2018 23:26:12 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 6950720673 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linux-mips.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726562AbeLAKhF (ORCPT ); Sat, 1 Dec 2018 05:37:05 -0500 Received: from eddie.linux-mips.org ([148.251.95.138]:51374 "EHLO cvs.linux-mips.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725790AbeLAKhF (ORCPT ); Sat, 1 Dec 2018 05:37:05 -0500 Received: (from localhost user: 'macro', uid#1010) by eddie.linux-mips.org with ESMTP id S23992919AbeK3XZJgjDI7 (ORCPT ); Sat, 1 Dec 2018 00:25:09 +0100 Date: Fri, 30 Nov 2018 23:25:09 +0000 (GMT) From: "Maciej W. Rozycki" To: Bernd Petrovitsch cc: Ingo Molnar , Andy Lutomirski , X86 ML , LKML , Borislav Petkov , Peter Zijlstra , Tycho Andersen , Daniel Colascione , Florian Weimer , Carlos O'Donell , Rich Felker Subject: Re: Cleaning up numbering for new x86 syscalls? In-Reply-To: <87cbf7b4-9e77-adc1-8e18-14dd206f0b79@petrovitsch.priv.at> Message-ID: References: <20181120073352.GA79825@gmail.com> <87cbf7b4-9e77-adc1-8e18-14dd206f0b79@petrovitsch.priv.at> User-Agent: Alpine 2.21 (LFD 202 2017-01-01) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 21 Nov 2018, Bernd Petrovitsch wrote: > And yes, lots of stuff will not compile out of the box (especially if > one uses a somewhat sane set of gcc options - not only -Wall -Wextra > -Werror) but if one gets software to compile for i386 and x86_64, > getting it to compile for x32 is a Friday afternoon job (more or less). > And yes, there is enough hardware/systems out there that uses 64bit CPUs > (for whatever reason - if only that one can't get a 32bit CPU for that > board) but will never ever need more than 2-3 GB RAM ..... The functionally equivalent 64-bit ILP32 MIPS n32 ABI has been around supported by Linux and the GNU toolchain for some 17 years now and people have been using it, so by now any sane piece of software that does not use handcoded assembly should work out of the box for the x86-64 x32 ABI as well. NB the important advantage of an LP64 ABI over an ILP32 ABI is the ability to mmap(2) files that exceed 4GiB in size (and in reality even smaller ones, as some user VM space is surely needed for other stuff), regardless of how much physical RAM is actually supported or has been installed. And these days even a web browser can easily overrun a 4GiB VM space. :( FWIW, Maciej