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=-5.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 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 7BA3DC43460 for ; Tue, 4 May 2021 12:17:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4DA9E600D4 for ; Tue, 4 May 2021 12:17:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230306AbhEDMSM (ORCPT ); Tue, 4 May 2021 08:18:12 -0400 Received: from mx2.suse.de ([195.135.220.15]:33668 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230188AbhEDMSL (ORCPT ); Tue, 4 May 2021 08:18:11 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id A0178AE5E; Tue, 4 May 2021 12:17:15 +0000 (UTC) Date: Tue, 4 May 2021 14:17:13 +0200 From: Michal =?iso-8859-1?Q?Such=E1nek?= To: Miguel Ojeda Cc: Ben Dooks , Albert Ou , Arnd Bergmann , Linux Kbuild mailing list , Greg Kroah-Hartman , Masahiro Yamada , Jonathan Corbet , Linux Doc Mailing List , linux-kernel , Miguel Ojeda , Will Deacon , Palmer Dabbelt , Paul Walmsley , Catalin Marinas , Joe Perches , Paul Mackerras , linux-riscv , linuxppc-dev , Linus Torvalds , Linux ARM Subject: Re: [PATCH] Raise the minimum GCC version to 5.2 Message-ID: <20210504121713.GT6564@kitsune.suse.cz> References: <20210501151538.145449-1-masahiroy@kernel.org> <3943bc020f6227c8801907317fc113aa13ad4bad.camel@perches.com> <65cda2bb-1b02-6ebc-0ea2-c48927524aa0@codethink.co.uk> <20210504092225.GS6564@kitsune.suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: User-Agent: Mutt/1.11.3 (2019-02-01) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, May 04, 2021 at 02:09:24PM +0200, Miguel Ojeda wrote: > On Tue, May 4, 2021 at 11:22 AM Michal Suchánek wrote: > > > > Except it makes answering the question "Is this bug we see on this > > ancient system still present in upstream?" needlessly more difficult to > > answer. > > Can you please provide some details? If you are talking about testing > a new kernel image in the ancient system "as-is", why wouldn't you > build it in a newer system? If you are talking about particular > problems about bisecting (kernel, compiler) pairs etc., details would > also be welcome. Yes, bisecting comes to mind. If you need to switch the userspace as well the bisection results are not that solid. You may not be even able to bisect because the workload does not exist on a new system at all. Crafting a minimal test case that can be forward-ported to a new system is not always trivial - if you understood the problem to that extent you might not even need to bisect it in the first place. Thanks Michal