From mboxrd@z Thu Jan 1 00:00:00 1970 From: Nicholas Piggin Subject: Re: [RFC][PATCH 0/5] kbuild changes, thin archives, --gc-sections Date: Fri, 5 Aug 2016 23:32:52 +1000 Message-ID: <20160805233252.50cb8cce@roar.ozlabs.ibm.com> References: <1470399123-8455-1-git-send-email-npiggin@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1470399123-8455-1-git-send-email-npiggin@gmail.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: linuxppc-dev-bounces+glppe-linuxppc-embedded-2=m.gmane.org@lists.ozlabs.org Sender: "Linuxppc-dev" To: linux-kbuild@vger.kernel.org Cc: linux-arch@vger.kernel.org, Stephen Rothwell , Arnd Bergmann , Nicolas Pitre , Alan Modra , linuxppc-dev@lists.ozlabs.org List-Id: linux-arch.vger.kernel.org On Fri, 5 Aug 2016 22:11:58 +1000 Nicholas Piggin wrote: > Hello, > > I have 3 different things in this patchset. All arch specific, but all > involve kbuild changes, so I'd like to discuss them with kbuild > maintainers. The goal has been to improve long standing linking > difficulties with the powerpc kernel. Here's a 30 second hack of an x86 patch. It seems to build and boot defconfig in a really quick kvm test. For x86-64 machine building x86 target, defconfig, make -j8 vmlinux time: orig thinarc thinarc+dce real 4m58.865s 4m59.747s 5m20.028s user 15m14.428s 15m13.868s 15m17.012s sys 0m57.296s 0m55.904s 0m58.416s build output directory size: orig thinarc thinarc+dce 317M 257M 285M vmlinux size: text data bss dec filename 10192338 4360136 1105920 15658394 vmlinux 10186739 4356040 1105920 15648699 vmlinux.thinarc 9580486 3759880 1011712 14352078 vmlinux.thinarc+dce Thanks, Nick diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 0a7b885..845069e 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -51,6 +51,8 @@ config X86 select ARCH_WANT_IPC_PARSE_VERSION if X86_32 select ARCH_WANT_OPTIONAL_GPIOLIB select BUILDTIME_EXTABLE_SORT + select THIN_ARCHIVES + select LINKER_DCE select CLKEVT_I8253 select CLKSRC_I8253 if X86_32 select CLOCKSOURCE_VALIDATE_LAST_CYCLE diff --git a/arch/x86/kernel/vmlinux.lds.S b/arch/x86/kernel/vmlinux.lds.S index 9297a00..7395dd8 100644 --- a/arch/x86/kernel/vmlinux.lds.S +++ b/arch/x86/kernel/vmlinux.lds.S @@ -92,7 +92,7 @@ SECTIONS .text : AT(ADDR(.text) - LOAD_OFFSET) { _text = .; /* bootstrapping code */ - HEAD_TEXT + KEEP(HEAD_TEXT) . = ALIGN(8); _stext = .; TEXT_TEXT @@ -321,7 +321,7 @@ SECTIONS .bss : AT(ADDR(.bss) - LOAD_OFFSET) { __bss_start = .; *(.bss..page_aligned) - *(.bss) + *(.bss .bss.*) . = ALIGN(PAGE_SIZE); __bss_stop = .; } From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pa0-f68.google.com ([209.85.220.68]:33353 "EHLO mail-pa0-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753746AbcHENsZ (ORCPT ); Fri, 5 Aug 2016 09:48:25 -0400 Date: Fri, 5 Aug 2016 23:32:52 +1000 From: Nicholas Piggin Subject: Re: [RFC][PATCH 0/5] kbuild changes, thin archives, --gc-sections Message-ID: <20160805233252.50cb8cce@roar.ozlabs.ibm.com> In-Reply-To: <1470399123-8455-1-git-send-email-npiggin@gmail.com> References: <1470399123-8455-1-git-send-email-npiggin@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-arch-owner@vger.kernel.org List-ID: To: linux-kbuild@vger.kernel.org Cc: linux-arch@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, Stephen Rothwell , Arnd Bergmann , Nicolas Pitre , Segher Boessenkool , Alan Modra Message-ID: <20160805133252.yFSFtRf6c3J0MV0p5hNXobr7pjTfcvw6IUDLA_cIfko@z> On Fri, 5 Aug 2016 22:11:58 +1000 Nicholas Piggin wrote: > Hello, > > I have 3 different things in this patchset. All arch specific, but all > involve kbuild changes, so I'd like to discuss them with kbuild > maintainers. The goal has been to improve long standing linking > difficulties with the powerpc kernel. Here's a 30 second hack of an x86 patch. It seems to build and boot defconfig in a really quick kvm test. For x86-64 machine building x86 target, defconfig, make -j8 vmlinux time: orig thinarc thinarc+dce real 4m58.865s 4m59.747s 5m20.028s user 15m14.428s 15m13.868s 15m17.012s sys 0m57.296s 0m55.904s 0m58.416s build output directory size: orig thinarc thinarc+dce 317M 257M 285M vmlinux size: text data bss dec filename 10192338 4360136 1105920 15658394 vmlinux 10186739 4356040 1105920 15648699 vmlinux.thinarc 9580486 3759880 1011712 14352078 vmlinux.thinarc+dce Thanks, Nick diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 0a7b885..845069e 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -51,6 +51,8 @@ config X86 select ARCH_WANT_IPC_PARSE_VERSION if X86_32 select ARCH_WANT_OPTIONAL_GPIOLIB select BUILDTIME_EXTABLE_SORT + select THIN_ARCHIVES + select LINKER_DCE select CLKEVT_I8253 select CLKSRC_I8253 if X86_32 select CLOCKSOURCE_VALIDATE_LAST_CYCLE diff --git a/arch/x86/kernel/vmlinux.lds.S b/arch/x86/kernel/vmlinux.lds.S index 9297a00..7395dd8 100644 --- a/arch/x86/kernel/vmlinux.lds.S +++ b/arch/x86/kernel/vmlinux.lds.S @@ -92,7 +92,7 @@ SECTIONS .text : AT(ADDR(.text) - LOAD_OFFSET) { _text = .; /* bootstrapping code */ - HEAD_TEXT + KEEP(HEAD_TEXT) . = ALIGN(8); _stext = .; TEXT_TEXT @@ -321,7 +321,7 @@ SECTIONS .bss : AT(ADDR(.bss) - LOAD_OFFSET) { __bss_start = .; *(.bss..page_aligned) - *(.bss) + *(.bss .bss.*) . = ALIGN(PAGE_SIZE); __bss_stop = .; }