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=-0.7 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no 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 4F20BC32771 for ; Mon, 27 Jan 2020 07:26:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 264EF20702 for ; Mon, 27 Jan 2020 07:26:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725985AbgA0H0W (ORCPT ); Mon, 27 Jan 2020 02:26:22 -0500 Received: from mout.kundenserver.de ([212.227.126.131]:37505 "EHLO mout.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725765AbgA0H0V (ORCPT ); Mon, 27 Jan 2020 02:26:21 -0500 Received: from mail-qk1-f178.google.com ([209.85.222.178]) by mrelayeu.kundenserver.de (mreue009 [212.227.15.129]) with ESMTPSA (Nemesis) id 1MQeIA-1jGO0w1Lni-00NkXH; Mon, 27 Jan 2020 08:26:20 +0100 Received: by mail-qk1-f178.google.com with SMTP id q15so8681606qke.9; Sun, 26 Jan 2020 23:26:20 -0800 (PST) X-Gm-Message-State: APjAAAXo6yGNTX4WiZmZRQfrosrPSVm7SjLJUIwyt/DfqlYhuyX5Yi2a rLBGazeqeZTAdef0YYieKRLfngPgXv4iPkT1fsU= X-Google-Smtp-Source: APXvYqxlylkK1tDp0siCP+ozzjLtsjUJ1/pYYXDqAsuxoykoyBiDLDdftjf04CgOzZk2GHrZ8hTORthbFnaJFMo2yc0= X-Received: by 2002:a05:620a:12e1:: with SMTP id f1mr14839537qkl.394.1580109979147; Sun, 26 Jan 2020 23:26:19 -0800 (PST) MIME-Version: 1.0 References: <20200123153341.19947-1-will@kernel.org> <26ad7a8a975c4e06b44a3184d7c86e5f@AcuMS.aculab.com> <20200123171641.GC20126@willie-the-truck> <2bfe2be6da484f15b0d229dd02d16ae6@AcuMS.aculab.com> <20200123190125.GA2683468@rani.riverdale.lan> <20200126010959.vhq7mg4esoq5w26j@e107158-lin.cambridge.arm.com> In-Reply-To: <20200126010959.vhq7mg4esoq5w26j@e107158-lin.cambridge.arm.com> From: Arnd Bergmann Date: Mon, 27 Jan 2020 08:26:03 +0100 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH v2 00/10] Rework READ_ONCE() to improve codegen To: Qais Yousef Cc: Arvind Sankar , Nick Desaulniers , David Laight , Will Deacon , "linux-kernel@vger.kernel.org" , "linux-arch@vger.kernel.org" , "kernel-team@android.com" , Michael Ellerman , Peter Zijlstra , Linus Torvalds , Segher Boessenkool , Christian Borntraeger , Luc Van Oostenryck , Peter Oberparleiter , Masahiro Yamada Content-Type: text/plain; charset="UTF-8" X-Provags-ID: V03:K1:ahfyygVcR59V0LNaGPKYoyNS1BjUiiy8xN3GSibjLksSJclAyZJ LMCHKHudTnjEKO8AmJ3yN3xpfFPamCml9t1e7fwZJXlDSXck4+bPhE4pxH7FE4ls88jd2bk IvfxfNYmjsaIJQVWMIi3bMrcvG/jx0JBQo3CacojQZM8qlCWOQb8gyzZ5K7/NtKJSMppByY vVmEzb6cShDXHeYj87CiA== X-UI-Out-Filterresults: notjunk:1;V03:K0:SckyZFLtMSg=:lyWcXYdhWBXEXYN4cGLYiF lYa2Ta3dgLaUcB2FcogMXdDX5dyefS5hU0nvIpTMIcSzS2LxhEe39zYnv1m/n/LKg1oxoAcPw TmjBXKge/hHBi9uW3B9qmcTx/LNXM8vnKjEtbkgnF9uVj8eNJzc20Rx9RlXUUBuEOHNfCvgiX g9h/aC+4i+Vm4XikHqiX1e5mur8AiQrUtSD7e/A71+PduXc4WYsE+rruYjq7vsqcXUy9dRovv 9TeWGbMKaQ6vQ/X2qRD37qoCtcoFLagLjLhGY2JPOgX9bC56G8ZjC8boJuR5AU620OeLyiRga yOmzyCsli3G7AVQ2mEDzYSoGPxtiREXpH/OksQVkA6lq+Q4dk8uvAeXLU2gW/tE1te6kaURBL MJtmJkJtPbw50Ga9ykrjldj7iQF3LkYF63fAQZYlTkzbAxuB9Kzn7xhyGSvSCGeT5v/N6mpET OD8fja5slfffpcwoO5O6FIt1purlDTKbzpzBnSGzVDtr92huRiEf+sSuT2ekcE85VL2uNfpvh b88SCFTDJRjhb8VS0+IfxOYjSg227GRoo97VJtPk0M3gshSf+onSv0imMvmMNVDPzFj5BymUD fuApRs53wgGuRd0QZKOj3d9O309V8huI8OMOn/qV4u5ONZQW5ty543uv/Cpxig9ch6Mhxv9Uj jJfw/pClXRXPNrYNaSSymqEk+E6dDEfBofD5G0hyViLY9zuDqQSyR6QOreIgwlu8c6yYGAxu0 +uT0GVJ7Gwl/xDMUNXRm0P82fsYSQg3Il6Tu0hFGVzGzO1c0k6cTwMEyUPnlIy9QZKiEXxka7 lLtD1mj4rB+z99Q00KUbAuO+9jFzNyWon4HkpD9ggCnfH8QUpE= Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sun, Jan 26, 2020 at 2:10 AM Qais Yousef wrote: > On 01/23/20 14:01, Arvind Sankar wrote: > > On Thu, Jan 23, 2020 at 10:45:08AM -0800, Nick Desaulniers wrote: > > > On Thu, Jan 23, 2020 at 9:32 AM David Laight wrote: > > > > Reposting Arnd's link > > https://www.spinics.net/lists/linux-kbuild/msg23648.html > > This list seems to be x86 centric? I remember when the switch to GCC 4.6 > happened a couple or more archs had to be dropped because they lacked a newer > compiler. There are two architectures that already had problems last time: - unicore32 never had any compiler that shipped with sources, only an ancient set of gcc binaries that already had problems building the kernel during the move to gcc-4.6. The maintainer said he'd work on providing support for modern gcc or clang, but I don't think anything came out of that. - hexagon had an unmaintained gcc-4.5 port, but internally Qualcomm were already using clang to build their kernels, which should now work with the upstream version. I don't think there are any plans to have a more modern gcc. Everything else works with mainline gcc now, openrisc and csky were the last to get added in gcc-9. Some of the older sub-targets (armv3, s390-g6, powerpcspe) are removed in gcc-9, but these have a few more years before we need to worry about them. Arnd