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* [PATCH] kbuild: switch to thin archives
@ 2017-06-02 12:54 Nicholas Piggin
  2017-06-02 20:57 ` kbuild test robot
                   ` (2 more replies)
  0 siblings, 3 replies; 7+ messages in thread
From: Nicholas Piggin @ 2017-06-02 12:54 UTC (permalink / raw)
  To: linux-kernel; +Cc: Nicholas Piggin

Switch from incremental build to thin archives for packaging built-in.o.
binutils version must be bumped to 2.20. Proposed patch for 4.13.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---

 Documentation/process/changes.rst |  9 ++++-----
 Makefile                          |  3 +++
 arch/Kconfig                      |  6 ------
 arch/powerpc/Kconfig              |  8 --------
 scripts/Makefile.build            | 27 ++++++-------------------
 scripts/link-vmlinux.sh           | 42 +++++++++------------------------------
 6 files changed, 22 insertions(+), 73 deletions(-)

diff --git a/Documentation/process/changes.rst b/Documentation/process/changes.rst
index e25d63f8c0da..56fd0687bd4a 100644
--- a/Documentation/process/changes.rst
+++ b/Documentation/process/changes.rst
@@ -31,7 +31,7 @@ you probably needn't concern yourself with isdn4k-utils.
 ====================== ===============  ========================================
 GNU C                  3.2              gcc --version
 GNU make               3.81             make --version
-binutils               2.12             ld -v
+binutils               2.20             ld -v
 util-linux             2.10o            fdformat --version
 module-init-tools      0.9.10           depmod -V
 e2fsprogs              1.41.4           e2fsck -V
@@ -75,10 +75,9 @@ You will need GNU make 3.81 or later to build the kernel.
 Binutils
 --------
 
-Linux on IA-32 has recently switched from using ``as86`` to using ``gas`` for
-assembling the 16-bit boot code, removing the need for ``as86`` to compile
-your kernel.  This change does, however, mean that you need a recent
-release of binutils.
+The build system has recently switched to using thin archives (`ar T`) rather
+than incremental linking (`ld -r`) for built-in.o intermediate steps. This
+requires binutils 2.20 or newer.
 
 Perl
 ----
diff --git a/Makefile b/Makefile
index 470bd4d9513a..58658d7a04a0 100644
--- a/Makefile
+++ b/Makefile
@@ -818,6 +818,9 @@ KBUILD_CFLAGS   += $(call cc-option,-Werror=designated-init)
 # use the deterministic mode of AR if available
 KBUILD_ARFLAGS := $(call ar-option,D)
 
+# Use thin archives.
+KBUILD_ARFLAGS :=$(KBUILD_ARFLAGS)T
+
 include scripts/Makefile.kasan
 include scripts/Makefile.extrawarn
 include scripts/Makefile.ubsan
diff --git a/arch/Kconfig b/arch/Kconfig
index 6c00e5b00f8b..0a306916968a 100644
--- a/arch/Kconfig
+++ b/arch/Kconfig
@@ -510,12 +510,6 @@ config CC_STACKPROTECTOR_STRONG
 
 endchoice
 
-config THIN_ARCHIVES
-	bool
-	help
-	  Select this if the architecture wants to use thin archives
-	  instead of ld -r to create the built-in.o files.
-
 config LD_DEAD_CODE_DATA_ELIMINATION
 	bool
 	help
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index f7c8f9972f61..80d882a78426 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -472,14 +472,6 @@ config MPROFILE_KERNEL
 	depends on PPC64 && CPU_LITTLE_ENDIAN
 	def_bool !DISABLE_MPROFILE_KERNEL
 
-config USE_THIN_ARCHIVES
-	bool "Build the kernel using thin archives"
-	default n
-	select THIN_ARCHIVES
-	help
-	  Build the kernel using thin archives.
-	  If you're unsure say N.
-
 config IOMMU_HELPER
 	def_bool PPC64
 
diff --git a/scripts/Makefile.build b/scripts/Makefile.build
index 733e044fff8b..6cc07d09fce3 100644
--- a/scripts/Makefile.build
+++ b/scripts/Makefile.build
@@ -436,15 +436,9 @@ $(sort $(subdir-obj-y)): $(subdir-ym) ;
 #
 ifdef builtin-target
 
-ifdef CONFIG_THIN_ARCHIVES
-  cmd_make_builtin = rm -f $@; $(AR) rcST$(KBUILD_ARFLAGS)
-  cmd_make_empty_builtin = rm -f $@; $(AR) rcST$(KBUILD_ARFLAGS)
-  quiet_cmd_link_o_target = AR      $@
-else
-  cmd_make_builtin = $(LD) $(ld_flags) -r -o
-  cmd_make_empty_builtin = rm -f $@; $(AR) rcs$(KBUILD_ARFLAGS)
-  quiet_cmd_link_o_target = LD      $@
-endif
+cmd_make_builtin = rm -f $@; $(AR) rcS$(KBUILD_ARFLAGS)
+cmd_make_empty_builtin = rm -f $@; $(AR) rcS$(KBUILD_ARFLAGS)
+quiet_cmd_link_o_target = AR      $@
 
 # If the list of objects to link is empty, just create an empty built-in.o
 cmd_link_o_target = $(if $(strip $(obj-y)),\
@@ -477,11 +471,7 @@ $(modorder-target): $(subdir-ym) FORCE
 ifdef lib-target
 quiet_cmd_link_l_target = AR      $@
 
-ifdef CONFIG_THIN_ARCHIVES
-  cmd_link_l_target = rm -f $@; $(AR) rcsT$(KBUILD_ARFLAGS) $@ $(lib-y)
-else
-  cmd_link_l_target = rm -f $@; $(AR) rcs$(KBUILD_ARFLAGS) $@ $(lib-y)
-endif
+cmd_link_l_target = rm -f $@; $(AR) rcs$(KBUILD_ARFLAGS) $@ $(lib-y)
 
 $(lib-target): $(lib-y) FORCE
 	$(call if_changed,link_l_target)
@@ -529,13 +519,8 @@ $($(subst $(obj)/,,$(@:.o=-m)))), $^)
 
 cmd_link_multi-link = $(LD) $(ld_flags) -r -o $@ $(link_multi_deps) $(cmd_secanalysis)
 
-ifdef CONFIG_THIN_ARCHIVES
-  quiet_cmd_link_multi-y = AR      $@
-  cmd_link_multi-y = rm -f $@; $(AR) rcST$(KBUILD_ARFLAGS) $@ $(link_multi_deps)
-else
-  quiet_cmd_link_multi-y = LD      $@
-  cmd_link_multi-y = $(cmd_link_multi-link)
-endif
+quiet_cmd_link_multi-y = AR      $@
+cmd_link_multi-y = rm -f $@; $(AR) rcS$(KBUILD_ARFLAGS) $@ $(link_multi_deps)
 
 quiet_cmd_link_multi-m = LD [M]  $@
 cmd_link_multi-m = $(cmd_link_multi-link)
diff --git a/scripts/link-vmlinux.sh b/scripts/link-vmlinux.sh
index c80291319cb2..ac0d3b2faa09 100755
--- a/scripts/link-vmlinux.sh
+++ b/scripts/link-vmlinux.sh
@@ -47,13 +47,11 @@ info()
 #
 archive_builtin()
 {
-	if [ -n "${CONFIG_THIN_ARCHIVES}" ]; then
-		info AR built-in.o
-		rm -f built-in.o;
-		${AR} rcsT${KBUILD_ARFLAGS} built-in.o			\
-					${KBUILD_VMLINUX_INIT}		\
-					${KBUILD_VMLINUX_MAIN}
-	fi
+	info AR built-in.o
+	rm -f built-in.o;
+	${AR} rcs${KBUILD_ARFLAGS} built-in.o			\
+				${KBUILD_VMLINUX_INIT}		\
+				${KBUILD_VMLINUX_MAIN}
 }
 
 # Link of vmlinux.o used for section mismatch analysis
@@ -62,14 +60,8 @@ modpost_link()
 {
 	local objects
 
-	if [ -n "${CONFIG_THIN_ARCHIVES}" ]; then
-		objects="--whole-archive built-in.o"
-	else
-		objects="${KBUILD_VMLINUX_INIT}				\
-			--start-group					\
-			${KBUILD_VMLINUX_MAIN}				\
-			--end-group"
-	fi
+	objects="--whole-archive built-in.o"
+
 	${LD} ${LDFLAGS} -r -o ${1} ${objects}
 }
 
@@ -82,28 +74,12 @@ vmlinux_link()
 	local objects
 
 	if [ "${SRCARCH}" != "um" ]; then
-		if [ -n "${CONFIG_THIN_ARCHIVES}" ]; then
-			objects="--whole-archive built-in.o ${1}"
-		else
-			objects="${KBUILD_VMLINUX_INIT}			\
-				--start-group				\
-				${KBUILD_VMLINUX_MAIN}			\
-				--end-group				\
-				${1}"
-		fi
+		objects="--whole-archive built-in.o ${1}"
 
 		${LD} ${LDFLAGS} ${LDFLAGS_vmlinux} -o ${2}		\
 			-T ${lds} ${objects}
 	else
-		if [ -n "${CONFIG_THIN_ARCHIVES}" ]; then
-			objects="-Wl,--whole-archive built-in.o ${1}"
-		else
-			objects="${KBUILD_VMLINUX_INIT}			\
-				-Wl,--start-group			\
-				${KBUILD_VMLINUX_MAIN}			\
-				-Wl,--end-group				\
-				${1}"
-		fi
+		objects="-Wl,--whole-archive built-in.o ${1}"
 
 		${CC} ${CFLAGS_vmlinux} -o ${2}				\
 			-Wl,-T,${lds}					\
-- 
2.11.0

^ permalink raw reply related	[flat|nested] 7+ messages in thread
* Re: [PATCH] kbuild: switch to thin archives
  2017-06-02 12:54 [PATCH] kbuild: switch to thin archives Nicholas Piggin
@ 2017-06-02 20:57 ` kbuild test robot
  2017-06-02 20:57 ` kbuild test robot
  2017-06-18 10:04 ` Pavel Machek
  2 siblings, 0 replies; 7+ messages in thread
From: kbuild test robot @ 2017-06-02 20:57 UTC (permalink / raw)
  To: Nicholas Piggin; +Cc: kbuild-all, linux-kernel, Nicholas Piggin

[-- Attachment #1: Type: text/plain, Size: 2805 bytes --]

Hi Nicholas,

[auto build test ERROR on linus/master]
[also build test ERROR on v4.12-rc3 next-20170602]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]

url:    https://github.com/0day-ci/linux/commits/Nicholas-Piggin/kbuild-switch-to-thin-archives/20170603-025436
config: ia64-allnoconfig (attached as .config)
compiler: ia64-linux-gcc (GCC) 6.2.0
reproduce:
        wget https://raw.githubusercontent.com/01org/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # save the attached .config to linux build tree
        make.cross ARCH=ia64 

All errors (new ones prefixed by >>):

   arch/ia64/kernel/entry.o: In function `ia64_work_processed_syscall':
>> (.text+0xa61): undefined reference to `__kernel_syscall_via_epc'
   arch/ia64/kernel/fsys.o: In function `fsys_bubble_down':
>> (.text+0x551): undefined reference to `__kernel_syscall_via_break'
   arch/ia64/kernel/patch.o: In function `ia64_patch_gate':
>> patch.c:(.init.text+0x3d1): undefined reference to `__start_gate_fsyscall_patchlist'
>> patch.c:(.init.text+0x3e0): undefined reference to `__end_gate_fsyscall_patchlist'
   patch.c:(.init.text+0x3f1): undefined reference to `__start_gate_fsyscall_patchlist'
   patch.c:(.init.text+0x400): undefined reference to `__end_gate_fsyscall_patchlist'
>> patch.c:(.init.text+0x4a0): undefined reference to `__start_gate_brl_fsys_bubble_down_patchlist'
>> patch.c:(.init.text+0x4a1): undefined reference to `__end_gate_brl_fsys_bubble_down_patchlist'
   patch.c:(.init.text+0x4b1): undefined reference to `__start_gate_brl_fsys_bubble_down_patchlist'
   patch.c:(.init.text+0x4c0): undefined reference to `__end_gate_brl_fsys_bubble_down_patchlist'
>> patch.c:(.init.text+0x560): undefined reference to `__end_gate_vtop_patchlist'
>> patch.c:(.init.text+0x561): undefined reference to `__start_gate_vtop_patchlist'
   patch.c:(.init.text+0x570): undefined reference to `__end_gate_vtop_patchlist'
   patch.c:(.init.text+0x571): undefined reference to `__start_gate_vtop_patchlist'
>> patch.c:(.init.text+0x580): undefined reference to `__end_gate_mckinley_e9_patchlist'
>> patch.c:(.init.text+0x581): undefined reference to `__start_gate_mckinley_e9_patchlist'
   patch.c:(.init.text+0x590): undefined reference to `__end_gate_mckinley_e9_patchlist'
   patch.c:(.init.text+0x591): undefined reference to `__start_gate_mckinley_e9_patchlist'
   arch/ia64/kernel/signal.o: In function `ia64_do_signal':
>> signal.c:(.text+0xf11): undefined reference to `__kernel_sigtramp'
   signal.c:(.text+0xf40): undefined reference to `__kernel_sigtramp'

---
0-DAY kernel test infrastructure                Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all                   Intel Corporation

[-- Attachment #2: .config.gz --]
[-- Type: application/gzip, Size: 5989 bytes --]

^ permalink raw reply	[flat|nested] 7+ messages in thread
* Re: [PATCH] kbuild: switch to thin archives
  2017-06-02 12:54 [PATCH] kbuild: switch to thin archives Nicholas Piggin
  2017-06-02 20:57 ` kbuild test robot
@ 2017-06-02 20:57 ` kbuild test robot
  2017-06-03  6:51   ` Nicholas Piggin
  2017-06-18 10:04 ` Pavel Machek
  2 siblings, 1 reply; 7+ messages in thread
From: kbuild test robot @ 2017-06-02 20:57 UTC (permalink / raw)
  To: Nicholas Piggin; +Cc: kbuild-all, linux-kernel, Nicholas Piggin

[-- Attachment #1: Type: text/plain, Size: 1386 bytes --]

Hi Nicholas,

[auto build test ERROR on linus/master]
[also build test ERROR on v4.12-rc3 next-20170602]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]

url:    https://github.com/0day-ci/linux/commits/Nicholas-Piggin/kbuild-switch-to-thin-archives/20170603-025436
config: parisc-c3000_defconfig (attached as .config)
compiler: hppa-linux-gnu-gcc (Debian 6.1.1-9) 6.1.1 20160705
reproduce:
        wget https://raw.githubusercontent.com/01org/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # save the attached .config to linux build tree
        make.cross ARCH=parisc 

All errors (new ones prefixed by >>):

   /usr/lib/gcc-cross/hppa-linux-gnu/6/libgcc.a(_ucmpdi2.o): In function `__ucmpdi2':
>> (.text+0x0): multiple definition of `__ucmpdi2'
   arch/parisc/lib/ucmpdi2.o:(.text.__ucmpdi2+0x0): first defined here
   /usr/lib/gcc-cross/hppa-linux-gnu/6/libgcc.a(fptr.o): In function `__canonicalize_funcptr_for_compare':
>> (.text+0x0): multiple definition of `__canonicalize_funcptr_for_compare'
   arch/parisc/kernel/real2.o:(.text+0x278): first defined here
   hppa-linux-gnu-ld: internal error ../../ld/ldlang.c 6366

---
0-DAY kernel test infrastructure                Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all                   Intel Corporation

[-- Attachment #2: .config.gz --]
[-- Type: application/gzip, Size: 14700 bytes --]

^ permalink raw reply	[flat|nested] 7+ messages in thread
* Re: [PATCH] kbuild: switch to thin archives
  2017-06-02 20:57 ` kbuild test robot
@ 2017-06-03  6:51   ` Nicholas Piggin
  0 siblings, 0 replies; 7+ messages in thread
From: Nicholas Piggin @ 2017-06-03  6:51 UTC (permalink / raw)
  To: kbuild test robot; +Cc: kbuild-all, linux-kernel

On Sat, 3 Jun 2017 04:57:21 +0800
kbuild test robot <lkp@intel.com> wrote:

> Hi Nicholas,
> 
> [auto build test ERROR on linus/master]
> [also build test ERROR on v4.12-rc3 next-20170602]
> [if your patch is applied to the wrong git tree, please drop us a note to help improve the system]

Thank you robot, can we try this one?

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 Documentation/process/changes.rst |  9 ++++-----
 Makefile                          |  3 +++
 arch/Kconfig                      |  6 ------
 arch/powerpc/Kconfig              |  8 --------
 arch/x86/um/vdso/Makefile         |  2 +-
 scripts/Makefile.build            | 27 ++++++-------------------
 scripts/link-vmlinux.sh           | 42 +++++++++------------------------------
 7 files changed, 23 insertions(+), 74 deletions(-)

diff --git a/Documentation/process/changes.rst b/Documentation/process/changes.rst
index e25d63f8c0da..56fd0687bd4a 100644
--- a/Documentation/process/changes.rst
+++ b/Documentation/process/changes.rst
@@ -31,7 +31,7 @@ you probably needn't concern yourself with isdn4k-utils.
 ====================== ===============  ========================================
 GNU C                  3.2              gcc --version
 GNU make               3.81             make --version
-binutils               2.12             ld -v
+binutils               2.20             ld -v
 util-linux             2.10o            fdformat --version
 module-init-tools      0.9.10           depmod -V
 e2fsprogs              1.41.4           e2fsck -V
@@ -75,10 +75,9 @@ You will need GNU make 3.81 or later to build the kernel.
 Binutils
 --------
 
-Linux on IA-32 has recently switched from using ``as86`` to using ``gas`` for
-assembling the 16-bit boot code, removing the need for ``as86`` to compile
-your kernel.  This change does, however, mean that you need a recent
-release of binutils.
+The build system has recently switched to using thin archives (`ar T`) rather
+than incremental linking (`ld -r`) for built-in.o intermediate steps. This
+requires binutils 2.20 or newer.
 
 Perl
 ----
diff --git a/Makefile b/Makefile
index 470bd4d9513a..58658d7a04a0 100644
--- a/Makefile
+++ b/Makefile
@@ -818,6 +818,9 @@ KBUILD_CFLAGS   += $(call cc-option,-Werror=designated-init)
 # use the deterministic mode of AR if available
 KBUILD_ARFLAGS := $(call ar-option,D)
 
+# must use thin archives.
+KBUILD_ARFLAGS :=$(KBUILD_ARFLAGS)T
+
 include scripts/Makefile.kasan
 include scripts/Makefile.extrawarn
 include scripts/Makefile.ubsan
diff --git a/arch/Kconfig b/arch/Kconfig
index 6c00e5b00f8b..0a306916968a 100644
--- a/arch/Kconfig
+++ b/arch/Kconfig
@@ -510,12 +510,6 @@ config CC_STACKPROTECTOR_STRONG
 
 endchoice
 
-config THIN_ARCHIVES
-	bool
-	help
-	  Select this if the architecture wants to use thin archives
-	  instead of ld -r to create the built-in.o files.
-
 config LD_DEAD_CODE_DATA_ELIMINATION
 	bool
 	help
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index f7c8f9972f61..80d882a78426 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -472,14 +472,6 @@ config MPROFILE_KERNEL
 	depends on PPC64 && CPU_LITTLE_ENDIAN
 	def_bool !DISABLE_MPROFILE_KERNEL
 
-config USE_THIN_ARCHIVES
-	bool "Build the kernel using thin archives"
-	default n
-	select THIN_ARCHIVES
-	help
-	  Build the kernel using thin archives.
-	  If you're unsure say N.
-
 config IOMMU_HELPER
 	def_bool PPC64
 
diff --git a/arch/x86/um/vdso/Makefile b/arch/x86/um/vdso/Makefile
index d72dec406ccb..329406224330 100644
--- a/arch/x86/um/vdso/Makefile
+++ b/arch/x86/um/vdso/Makefile
@@ -53,7 +53,7 @@ CFLAGS_REMOVE_vdso-note.o = -pg -fprofile-arcs -ftest-coverage
 CFLAGS_REMOVE_um_vdso.o = -pg -fprofile-arcs -ftest-coverage
 
 targets += vdso-syms.lds
-obj-$(VDSO64-y)			+= vdso-syms.lds
+extra-$(VDSO64-y)			+= vdso-syms.lds
 
 #
 # Match symbols in the DSO that look like VDSO*; produce a file of constants.
diff --git a/scripts/Makefile.build b/scripts/Makefile.build
index 733e044fff8b..6cc07d09fce3 100644
--- a/scripts/Makefile.build
+++ b/scripts/Makefile.build
@@ -436,15 +436,9 @@ $(sort $(subdir-obj-y)): $(subdir-ym) ;
 #
 ifdef builtin-target
 
-ifdef CONFIG_THIN_ARCHIVES
-  cmd_make_builtin = rm -f $@; $(AR) rcST$(KBUILD_ARFLAGS)
-  cmd_make_empty_builtin = rm -f $@; $(AR) rcST$(KBUILD_ARFLAGS)
-  quiet_cmd_link_o_target = AR      $@
-else
-  cmd_make_builtin = $(LD) $(ld_flags) -r -o
-  cmd_make_empty_builtin = rm -f $@; $(AR) rcs$(KBUILD_ARFLAGS)
-  quiet_cmd_link_o_target = LD      $@
-endif
+cmd_make_builtin = rm -f $@; $(AR) rcS$(KBUILD_ARFLAGS)
+cmd_make_empty_builtin = rm -f $@; $(AR) rcS$(KBUILD_ARFLAGS)
+quiet_cmd_link_o_target = AR      $@
 
 # If the list of objects to link is empty, just create an empty built-in.o
 cmd_link_o_target = $(if $(strip $(obj-y)),\
@@ -477,11 +471,7 @@ $(modorder-target): $(subdir-ym) FORCE
 ifdef lib-target
 quiet_cmd_link_l_target = AR      $@
 
-ifdef CONFIG_THIN_ARCHIVES
-  cmd_link_l_target = rm -f $@; $(AR) rcsT$(KBUILD_ARFLAGS) $@ $(lib-y)
-else
-  cmd_link_l_target = rm -f $@; $(AR) rcs$(KBUILD_ARFLAGS) $@ $(lib-y)
-endif
+cmd_link_l_target = rm -f $@; $(AR) rcs$(KBUILD_ARFLAGS) $@ $(lib-y)
 
 $(lib-target): $(lib-y) FORCE
 	$(call if_changed,link_l_target)
@@ -529,13 +519,8 @@ $($(subst $(obj)/,,$(@:.o=-m)))), $^)
 
 cmd_link_multi-link = $(LD) $(ld_flags) -r -o $@ $(link_multi_deps) $(cmd_secanalysis)
 
-ifdef CONFIG_THIN_ARCHIVES
-  quiet_cmd_link_multi-y = AR      $@
-  cmd_link_multi-y = rm -f $@; $(AR) rcST$(KBUILD_ARFLAGS) $@ $(link_multi_deps)
-else
-  quiet_cmd_link_multi-y = LD      $@
-  cmd_link_multi-y = $(cmd_link_multi-link)
-endif
+quiet_cmd_link_multi-y = AR      $@
+cmd_link_multi-y = rm -f $@; $(AR) rcS$(KBUILD_ARFLAGS) $@ $(link_multi_deps)
 
 quiet_cmd_link_multi-m = LD [M]  $@
 cmd_link_multi-m = $(cmd_link_multi-link)
diff --git a/scripts/link-vmlinux.sh b/scripts/link-vmlinux.sh
index c80291319cb2..a7d319db58f6 100755
--- a/scripts/link-vmlinux.sh
+++ b/scripts/link-vmlinux.sh
@@ -47,13 +47,11 @@ info()
 #
 archive_builtin()
 {
-	if [ -n "${CONFIG_THIN_ARCHIVES}" ]; then
-		info AR built-in.o
-		rm -f built-in.o;
-		${AR} rcsT${KBUILD_ARFLAGS} built-in.o			\
-					${KBUILD_VMLINUX_INIT}		\
-					${KBUILD_VMLINUX_MAIN}
-	fi
+	info AR built-in.o
+	rm -f built-in.o;
+	${AR} rcs${KBUILD_ARFLAGS} built-in.o			\
+				${KBUILD_VMLINUX_INIT}		\
+				${KBUILD_VMLINUX_MAIN}
 }
 
 # Link of vmlinux.o used for section mismatch analysis
@@ -62,14 +60,8 @@ modpost_link()
 {
 	local objects
 
-	if [ -n "${CONFIG_THIN_ARCHIVES}" ]; then
-		objects="--whole-archive built-in.o"
-	else
-		objects="${KBUILD_VMLINUX_INIT}				\
-			--start-group					\
-			${KBUILD_VMLINUX_MAIN}				\
-			--end-group"
-	fi
+	objects="--whole-archive built-in.o --no-whole-archive"
+
 	${LD} ${LDFLAGS} -r -o ${1} ${objects}
 }
 
@@ -82,28 +74,12 @@ vmlinux_link()
 	local objects
 
 	if [ "${SRCARCH}" != "um" ]; then
-		if [ -n "${CONFIG_THIN_ARCHIVES}" ]; then
-			objects="--whole-archive built-in.o ${1}"
-		else
-			objects="${KBUILD_VMLINUX_INIT}			\
-				--start-group				\
-				${KBUILD_VMLINUX_MAIN}			\
-				--end-group				\
-				${1}"
-		fi
+		objects="--whole-archive built-in.o ${1} --no-whole-archive"
 
 		${LD} ${LDFLAGS} ${LDFLAGS_vmlinux} -o ${2}		\
 			-T ${lds} ${objects}
 	else
-		if [ -n "${CONFIG_THIN_ARCHIVES}" ]; then
-			objects="-Wl,--whole-archive built-in.o ${1}"
-		else
-			objects="${KBUILD_VMLINUX_INIT}			\
-				-Wl,--start-group			\
-				${KBUILD_VMLINUX_MAIN}			\
-				-Wl,--end-group				\
-				${1}"
-		fi
+		objects="-Wl,--whole-archive built-in.o ${1} -Wl,--no-whole-archive"
 
 		${CC} ${CFLAGS_vmlinux} -o ${2}				\
 			-Wl,-T,${lds}					\
-- 
2.11.0

^ permalink raw reply related	[flat|nested] 7+ messages in thread
* Re: [PATCH] kbuild: switch to thin archives
  2017-06-02 12:54 [PATCH] kbuild: switch to thin archives Nicholas Piggin
  2017-06-02 20:57 ` kbuild test robot
  2017-06-02 20:57 ` kbuild test robot
@ 2017-06-18 10:04 ` Pavel Machek
  2017-06-19  7:45   ` Nicholas Piggin
  2 siblings, 1 reply; 7+ messages in thread
From: Pavel Machek @ 2017-06-18 10:04 UTC (permalink / raw)
  To: Nicholas Piggin; +Cc: linux-kernel

[-- Attachment #1: Type: text/plain, Size: 476 bytes --]

On Fri 2017-06-02 22:54:54, Nicholas Piggin wrote:
> Switch from incremental build to thin archives for packaging built-in.o.
> binutils version must be bumped to 2.20. Proposed patch for 4.13.
> 
> Signed-off-by: Nicholas Piggin <npiggin@gmail.com>

You should explain any advantage this is supposed to have.

									Pavel

-- 
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html

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^ permalink raw reply	[flat|nested] 7+ messages in thread
* Re: [PATCH] kbuild: switch to thin archives
  2017-06-18 10:04 ` Pavel Machek
@ 2017-06-19  7:45   ` Nicholas Piggin
  2017-06-19  9:15     ` Pavel Machek
  0 siblings, 1 reply; 7+ messages in thread
From: Nicholas Piggin @ 2017-06-19  7:45 UTC (permalink / raw)
  To: Pavel Machek; +Cc: linux-kernel

On Sun, 18 Jun 2017 12:04:26 +0200
Pavel Machek <pavel@ucw.cz> wrote:

> On Fri 2017-06-02 22:54:54, Nicholas Piggin wrote:
> > Switch from incremental build to thin archives for packaging built-in.o.
> > binutils version must be bumped to 2.20. Proposed patch for 4.13.
> > 
> > Signed-off-by: Nicholas Piggin <npiggin@gmail.com>  
> 
> You should explain any advantage this is supposed to have.

Hi Pavel,

You're right, sorry for this, I was spamming the list with a quick
hack to try to get 0day to pick up the patch.

Most of the discussion has been going on in other patch series (check
linux-kbuild).

There are 3 main categories of advantages.

First is reduced size of intermediate artifacts in the build output
tree.

Second is that incremental linking constrains the linker because it
has to assemble each section in the output as a sequence of those
section from the inputs. So the more incremental linking, the more
you constrain the linker, and this can end up resulting in link fail
with large kernels on some architectures.

Third is that some link-time optimizations are not compatible or
not very optimal with incremental linking, whereas thin archives
is much more amenable to such things.

Thanks,
Nick

^ permalink raw reply	[flat|nested] 7+ messages in thread
* Re: [PATCH] kbuild: switch to thin archives
  2017-06-19  7:45   ` Nicholas Piggin
@ 2017-06-19  9:15     ` Pavel Machek
  0 siblings, 0 replies; 7+ messages in thread
From: Pavel Machek @ 2017-06-19  9:15 UTC (permalink / raw)
  To: Nicholas Piggin; +Cc: linux-kernel

[-- Attachment #1: Type: text/plain, Size: 1609 bytes --]

On Mon 2017-06-19 17:45:21, Nicholas Piggin wrote:
> On Sun, 18 Jun 2017 12:04:26 +0200
> Pavel Machek <pavel@ucw.cz> wrote:
> 
> > On Fri 2017-06-02 22:54:54, Nicholas Piggin wrote:
> > > Switch from incremental build to thin archives for packaging built-in.o.
> > > binutils version must be bumped to 2.20. Proposed patch for 4.13.
> > > 
> > > Signed-off-by: Nicholas Piggin <npiggin@gmail.com>  
> > 
> > You should explain any advantage this is supposed to have.
> 
> Hi Pavel,
> 
> You're right, sorry for this, I was spamming the list with a quick
> hack to try to get 0day to pick up the patch.
> 
> Most of the discussion has been going on in other patch series (check
> linux-kbuild).
> 
> There are 3 main categories of advantages.
> 
> First is reduced size of intermediate artifacts in the build output
> tree.
> 
> Second is that incremental linking constrains the linker because it
> has to assemble each section in the output as a sequence of those
> section from the inputs. So the more incremental linking, the more
> you constrain the linker, and this can end up resulting in link fail
> with large kernels on some architectures.
> 
> Third is that some link-time optimizations are not compatible or
> not very optimal with incremental linking, whereas thin archives
> is much more amenable to such things.

Thanks for explanation. I checked, and binutils version bumb will not
affect me, but...
									Pavel

-- 
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html

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^ permalink raw reply	[flat|nested] 7+ messages in thread
end of thread, other threads:[~2017-06-19  9:15 UTC | newest]

Thread overview: 7+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2017-06-02 12:54 [PATCH] kbuild: switch to thin archives Nicholas Piggin
2017-06-02 20:57 ` kbuild test robot
2017-06-02 20:57 ` kbuild test robot
2017-06-03  6:51   ` Nicholas Piggin
2017-06-18 10:04 ` Pavel Machek
2017-06-19  7:45   ` Nicholas Piggin
2017-06-19  9:15     ` Pavel Machek

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