From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mout.kundenserver.de ([212.227.17.10]:51999 "EHLO mout.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752005AbcHHJS5 (ORCPT ); Mon, 8 Aug 2016 05:18:57 -0400 From: Arnd Bergmann Subject: Re: [PATCH 1/5] kbuild: allow architectures to use thin archives instead of ld -r Date: Mon, 08 Aug 2016 11:18:44 +0200 Message-ID: <20344093.JroaIWMd3z@wuerfel> In-Reply-To: <20160808132532.3ce8c0b6@roar.ozlabs.ibm.com> References: <1470399123-8455-1-git-send-email-npiggin@gmail.com> <20160806201045.GA25821@ravnborg.org> <20160808132532.3ce8c0b6@roar.ozlabs.ibm.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" Sender: linux-kbuild-owner@vger.kernel.org List-ID: To: Nicholas Piggin Cc: Sam Ravnborg , linux-kbuild@vger.kernel.org, linux-arch@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, Stephen Rothwell , Nicolas Pitre , Segher Boessenkool , Alan Modra On Monday, August 8, 2016 1:25:32 PM CEST Nicholas Piggin wrote: > On Sat, 6 Aug 2016 22:10:45 +0200 > Sam Ravnborg wrote: > > > Hi Nicholas. > > > > On Fri, Aug 05, 2016 at 10:11:59PM +1000, Nicholas Piggin wrote: > > > From: Stephen Rothwell > > > > > > ld -r is an incremental link used to create built-in.o files in build > > > subdirectories. It produces relocatable object files containing all > > > its input files, and these are are then pulled together and relocated > > > in the final link. Aside from the bloat, this constrains the final > > > link relocations, which has bitten large powerpc builds with > > > unresolvable relocations in the final link. > > > > > > Alan Modra has recommended the kernel use thin archives for linking. > > > This is an alternative and means that the linker has more information > > > available to it when it links the kernel. > > > > > > This patch enables a config option architectures can select, > > If we want to do this, then I suggest to make the logic reverse. > > Architectures that for some reasons cannot use this should > > have the possibility to avoid it. But let it be enabled by default. > > I was thinking the build matrix (architectures x build options x toolchains) > is a bit too large to switch it for everybody. I've far from even tested it > for a fraction of powerpc builds. I would prefer arch maintainers to switch > it themselves, but I do hope we can move everybody and just remove the old > method within a few releases. > > But I'm happy to go with whatever arch and kbuild maintainers prefer, so I > appreciate any discussion on it. How about making the option visible for everyone with CONFIG_EXPERT? That way you don't get it by default, but you do get it with randconfig and allmodconfig build testing. Arnd