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=-0.9 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS 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 77686C07E85 for ; Tue, 11 Dec 2018 10:38:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4948B2082F for ; Tue, 11 Dec 2018 10:38:07 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 4948B2082F Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com 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 S1726401AbeLKKiG (ORCPT ); Tue, 11 Dec 2018 05:38:06 -0500 Received: from mx1.redhat.com ([209.132.183.28]:60842 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726114AbeLKKiF (ORCPT ); Tue, 11 Dec 2018 05:38:05 -0500 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 01C3F308427E; Tue, 11 Dec 2018 10:38:05 +0000 (UTC) Received: from oldenburg2.str.redhat.com (ovpn-116-82.ams2.redhat.com [10.36.116.82]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 0BDEF5D73F; Tue, 11 Dec 2018 10:37:59 +0000 (UTC) From: Florian Weimer To: John Paul Adrian Glaubitz Cc: Andy Lutomirski , X86 ML , LKML , Linux API , "H. Peter Anvin" , Peter Zijlstra , Borislav Petkov , Mike Frysinger , "H. J. Lu" , Rich Felker , x32@buildd.debian.org, Arnd Bergmann , Will Deacon , Catalin Marinas , Linus Torvalds Subject: Re: Can we drop upstream Linux x32 support? References: <70bb54b2-8ed3-b5ee-c02d-6ef66c4f27eb@physik.fu-berlin.de> Date: Tue, 11 Dec 2018 11:37:58 +0100 In-Reply-To: <70bb54b2-8ed3-b5ee-c02d-6ef66c4f27eb@physik.fu-berlin.de> (John Paul Adrian Glaubitz's message of "Tue, 11 Dec 2018 11:29:14 +0100") Message-ID: <87in00z6ux.fsf@oldenburg2.str.redhat.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/26.1 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.40]); Tue, 11 Dec 2018 10:38:05 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * John Paul Adrian Glaubitz: > As for the enterprise support, this seems to be correct. I don't know > of any enterprise distribution with x32 support either. Me neither. I would expect a pure userspace port, with limitations in what ioctls you can use, and perhaps support from GCC to share more APIs with the kernel. (I do not know of any plans to work on this.) > I'm not terribly opposed to this change. I'm usually for keeping support > for things that people are using, but the maintenance is a huge burden > to upstream projects, I'm fine with letting it go. Thank you for sharing your perspective. > If x32 is eventually to be removed, we should also take care of removing > x32 support from userland code. From the top of my head, this would at least > concern: > > * OpenJDK Note that OpenJDK (well, Hotspot) has its own 32-bit pointer support for the Java heap (compressed oops), so only the native code parts (and JNI) benefit from x32 anyway. Thanks, Florian