From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pa0-x244.google.com (mail-pa0-x244.google.com [IPv6:2607:f8b0:400e:c03::244]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 3s72qX4r1lzDqS5 for ; Mon, 8 Aug 2016 13:25:44 +1000 (AEST) Received: by mail-pa0-x244.google.com with SMTP id ez1so23153821pab.3 for ; Sun, 07 Aug 2016 20:25:43 -0700 (PDT) Date: Mon, 8 Aug 2016 13:25:32 +1000 From: Nicholas Piggin To: Sam Ravnborg Cc: linux-kbuild@vger.kernel.org, linux-arch@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, Stephen Rothwell , Arnd Bergmann , Nicolas Pitre , Segher Boessenkool , Alan Modra Subject: Re: [PATCH 1/5] kbuild: allow architectures to use thin archives instead of ld -r Message-ID: <20160808132532.3ce8c0b6@roar.ozlabs.ibm.com> In-Reply-To: <20160806201045.GA25821@ravnborg.org> References: <1470399123-8455-1-git-send-email-npiggin@gmail.com> <1470399123-8455-2-git-send-email-npiggin@gmail.com> <20160806201045.GA25821@ravnborg.org> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , 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. Thanks, Nick