From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from Chamillionaire.breakpoint.cc ([146.0.238.67]:57760 "EHLO Chamillionaire.breakpoint.cc" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753525AbcLQL36 (ORCPT ); Sat, 17 Dec 2016 06:29:58 -0500 Date: Sat, 17 Dec 2016 12:29:50 +0100 From: Sebastian Andrzej Siewior Subject: Re: [RFC] minimum gcc version for kernel: raise to gcc-4.3 or 4.6? Message-ID: <20161217112949.pghxlhdlxjzdumuo@mikejones.breakpoint.cc> References: <20161216105634.235457-1-arnd@arndb.de> <20161216170043.taaanbg5objnxjlh@breakpoint.cc> <2778134.jZdhGefl4B@wuerfel> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <2778134.jZdhGefl4B@wuerfel> Sender: linux-arch-owner@vger.kernel.org List-ID: To: Arnd Bergmann Cc: linux-arch@vger.kernel.org, linux-kbuild@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@vger.kernel.org, Russell King , Andrew Morton , kernel-build-reports@lists.linaro.org, kvmarm@lists.cs.columbia.edu, Geert Uytterhoeven Message-ID: <20161217112950.EsGfEd7s_pl8SdNRC7iY13uJKWqdpHKh1G6M0YmuVGY@z> On 2016-12-16 23:00:27 [+0100], Arnd Bergmann wrote: > On Friday, December 16, 2016 6:00:43 PM CET Sebastian Andrzej Siewior wrote: > > On 2016-12-16 11:56:21 [+0100], Arnd Bergmann wrote: > > > The original gcc-4.3 release was in early 2008. If we decide to still > > > support that, we probably want the first 10 quirks in this series, > > > while gcc-4.6 (released in 2011) requires none of them. > > > > It this min gcc thingy ARM only? > > This is part of the question that I'm trying to figure out myself. > > Clearly having the same minimum version across all architectures simplifies > things a lot, because many of the bugs in old versions are architecture > independent. agreed. > Then again, some architectures implicitly require a new version > because an old one never existed (e.g. arm64 or risc-v), while some other > architectures may require an old version. A new version is understandable. But why is an old version required? One thing is an enterprise distro that is "current" or "supported" and still stuck with gcc 4.1 because that is the version they decided to include in their release. This is sad. But you might want to ask yourself why you want the latest kernel but an old gcc / binutils. If you have an architecture that compiles with gcc v4.1 and not with gcc latest stable / trunk then it is a sign that this port is not supported properly / not heatly. One thing is something like avr32 which is not part of upstream gcc due to some legal reason (that was my understanding a few years ago). It might get to a problem for them once large parts of userland switch to a later C++ standard which is gcc-5+. > Arnd Sebastian