public inbox for linux-kernel@vger.kernel.org
 help / color / mirror / Atom feed
* [PATCH 0/4] Add support for compiling with -ffunction-sections -fdata-sections
@ 2009-03-24  5:28 Tim Abbott
  2009-03-24  5:28 ` [PATCH 1/4] Make section names compatible " Tim Abbott
  2009-03-24  6:07 ` [PATCH 0/4] Add support for compiling " Stephen Rothwell
  0 siblings, 2 replies; 9+ messages in thread
From: Tim Abbott @ 2009-03-24  5:28 UTC (permalink / raw)
  To: Linus Torvalds
  Cc: Linux kernel mailing list, Tim Abbott, Anders Kaseorg,
	Waseem Daher, Denys Vlasenko, Rusty Russell, Andi Kleen,
	H. Peter Anvin

Hi Linus,

I'd like to see this patch series merged for 2.6.30.  It applies on
top of your current master (aka v2.6.29).  Patch 1/4 would benefit
from special treatment during the merge window, since it makes many
small changes in lots of files, and thus is likely to conflict with
other changes; the other patches are fairly small.

The purpose of this patch series is to make it possible to build the
kernel with "gcc -ffunction-sections -fdata-sections".  There are two
major applications for this functionality: decreasing vmlinux image
size with --gc-sections, and Ksplice.

The original motivation for this functionality was to allow using the
linker's unused section garbage collection support (ld --gc-sections)
in order to get a smaller vmlinux image for embedded systems.  People
have been developing patches for supporting building the kernel with
-ffunction-sections -fdata-sections for this purpose for a few years
now (e.g. [1]).  The most recent previous set of patches for
--gc-sections was by Denys Vlasenko, and saved 10% on vmlinux size
with CONFIG_MODULES=n and 1% with CONFIG_MODULES=y [2,3,4].  The
primary source of complexity in the various patch series for doing
section garbage collection has been in the patches adding support for
compiling the kernel with -ffunction-sections -fdata-sections, so
merging this patch series should be a big step towards those
significant savings in kernel image size.

[1] <http://lkml.org/lkml/2006/6/4/169>
[2] <http://lkml.org/lkml/2007/9/5/90>
[3] <http://lkml.org/lkml/2007/9/7/110>
[4] <http://lkml.org/lkml/2008/7/1/499>

Support for building the kernel with -ffunction-sections
-fdata-sections is the only significant prerequisite change currently
required by Ksplice.  Ksplice is a system for updating the Linux
kernel without rebooting [5].

[5] <http://lkml.org/lkml/2009/2/24/362> is the latest version of the
Ksplice patch series

Patches 1/4, 2/4, and 3/4 are independent of each other, but
all three are prerequisites for patch 4/4.

--

Anders Kaseorg (1):
  modpost: Check the section flags, not name, to catch missing
    "ax"/"aw"

Denys Vlasenko (1):
  modpost: support objects with more than 64k sections

Tim Abbott (1):
  Make section names compatible with -ffunction-sections
    -fdata-sections

Waseem Daher (1):
  x86: Add an option to compile with -ffunction-sections
    -fdata-sections

 Documentation/mutex-design.txt              |    4 +-
 Makefile                                    |    4 +
 arch/alpha/kernel/head.S                    |    2 +-
 arch/alpha/kernel/init_task.c               |    2 +-
 arch/alpha/kernel/vmlinux.lds.S             |   14 ++--
 arch/arm/kernel/head-nommu.S                |    2 +-
 arch/arm/kernel/head.S                      |    2 +-
 arch/arm/kernel/init_task.c                 |    2 +-
 arch/arm/kernel/vmlinux.lds.S               |   14 ++--
 arch/arm/mm/proc-v6.S                       |    2 +-
 arch/arm/mm/proc-v7.S                       |    2 +-
 arch/arm/mm/tlb-v6.S                        |    2 +-
 arch/arm/mm/tlb-v7.S                        |    2 +-
 arch/avr32/kernel/init_task.c               |    2 +-
 arch/avr32/kernel/vmlinux.lds.S             |    6 +-
 arch/avr32/mm/init.c                        |    2 +-
 arch/blackfin/kernel/vmlinux.lds.S          |    2 +-
 arch/cris/kernel/process.c                  |    2 +-
 arch/cris/kernel/vmlinux.lds.S              |    2 +-
 arch/frv/kernel/break.S                     |    4 +-
 arch/frv/kernel/entry.S                     |    2 +-
 arch/frv/kernel/head-mmu-fr451.S            |    2 +-
 arch/frv/kernel/head-uc-fr401.S             |    2 +-
 arch/frv/kernel/head-uc-fr451.S             |    2 +-
 arch/frv/kernel/head-uc-fr555.S             |    2 +-
 arch/frv/kernel/head.S                      |    4 +-
 arch/frv/kernel/init_task.c                 |    2 +-
 arch/frv/kernel/vmlinux.lds.S               |   18 ++--
 arch/frv/mm/tlb-miss.S                      |    2 +-
 arch/h8300/boot/compressed/head.S           |    2 +-
 arch/h8300/boot/compressed/vmlinux.lds      |    2 +-
 arch/h8300/kernel/init_task.c               |    2 +-
 arch/h8300/kernel/vmlinux.lds.S             |    2 +-
 arch/ia64/include/asm/asmmacro.h            |   12 +-
 arch/ia64/include/asm/cache.h               |    2 +-
 arch/ia64/include/asm/percpu.h              |    2 +-
 arch/ia64/kernel/Makefile                   |    2 +-
 arch/ia64/kernel/gate-data.S                |    2 +-
 arch/ia64/kernel/gate.S                     |    8 +-
 arch/ia64/kernel/gate.lds.S                 |   10 +-
 arch/ia64/kernel/head.S                     |    2 +-
 arch/ia64/kernel/init_task.c                |    4 +-
 arch/ia64/kernel/ivt.S                      |    2 +-
 arch/ia64/kernel/minstate.h                 |    4 +-
 arch/ia64/kernel/paravirtentry.S            |    2 +-
 arch/ia64/kernel/vmlinux.lds.S              |   48 ++++----
 arch/ia64/kvm/vmm_ivt.S                     |    2 +-
 arch/ia64/xen/xensetup.S                    |    2 +-
 arch/m32r/kernel/head.S                     |    2 +-
 arch/m32r/kernel/init_task.c                |    2 +-
 arch/m32r/kernel/vmlinux.lds.S              |    8 +-
 arch/m68k/kernel/head.S                     |    2 +-
 arch/m68k/kernel/process.c                  |    2 +-
 arch/m68k/kernel/sun3-head.S                |    2 +-
 arch/m68k/kernel/vmlinux-std.lds            |    6 +-
 arch/m68k/kernel/vmlinux-sun3.lds           |    4 +-
 arch/m68knommu/kernel/init_task.c           |    2 +-
 arch/m68knommu/kernel/vmlinux.lds.S         |    6 +-
 arch/m68knommu/platform/68360/head-ram.S    |    2 +-
 arch/m68knommu/platform/68360/head-rom.S    |    2 +-
 arch/mips/kernel/init_task.c                |    2 +-
 arch/mips/kernel/vmlinux.lds.S              |    8 +-
 arch/mips/lasat/image/head.S                |    2 +-
 arch/mips/lasat/image/romscript.normal      |    2 +-
 arch/mn10300/kernel/head.S                  |    2 +-
 arch/mn10300/kernel/init_task.c             |    2 +-
 arch/mn10300/kernel/vmlinux.lds.S           |   16 ++--
 arch/parisc/include/asm/cache.h             |    2 +-
 arch/parisc/include/asm/system.h            |    2 +-
 arch/parisc/kernel/head.S                   |    2 +-
 arch/parisc/kernel/init_task.c              |    8 +-
 arch/parisc/kernel/vmlinux.lds.S            |   26 +++---
 arch/powerpc/include/asm/cache.h            |    2 +-
 arch/powerpc/include/asm/page_64.h          |    2 +-
 arch/powerpc/include/asm/ppc_asm.h          |    4 +-
 arch/powerpc/kernel/head_32.S               |    2 +-
 arch/powerpc/kernel/head_40x.S              |    2 +-
 arch/powerpc/kernel/head_44x.S              |    2 +-
 arch/powerpc/kernel/head_8xx.S              |    2 +-
 arch/powerpc/kernel/head_fsl_booke.S        |    2 +-
 arch/powerpc/kernel/init_task.c             |    2 +-
 arch/powerpc/kernel/machine_kexec_64.c      |    2 +-
 arch/powerpc/kernel/vdso.c                  |    2 +-
 arch/powerpc/kernel/vdso32/vdso32_wrapper.S |    2 +-
 arch/powerpc/kernel/vdso64/vdso64_wrapper.S |    2 +-
 arch/powerpc/kernel/vmlinux.lds.S           |   28 +++---
 arch/s390/include/asm/cache.h               |    2 +-
 arch/s390/kernel/head.S                     |    2 +-
 arch/s390/kernel/init_task.c                |    2 +-
 arch/s390/kernel/vdso.c                     |    2 +-
 arch/s390/kernel/vdso32/vdso32_wrapper.S    |    2 +-
 arch/s390/kernel/vdso64/vdso64_wrapper.S    |    2 +-
 arch/s390/kernel/vmlinux.lds.S              |   20 ++--
 arch/sh/include/asm/cache.h                 |    2 +-
 arch/sh/kernel/cpu/sh5/entry.S              |    4 +-
 arch/sh/kernel/head_32.S                    |    2 +-
 arch/sh/kernel/head_64.S                    |    2 +-
 arch/sh/kernel/init_task.c                  |    2 +-
 arch/sh/kernel/irq.c                        |    4 +-
 arch/sh/kernel/vmlinux_32.lds.S             |   14 ++--
 arch/sh/kernel/vmlinux_64.lds.S             |   14 ++--
 arch/sparc/boot/btfixupprep.c               |    4 +-
 arch/sparc/include/asm/cache.h              |    2 +-
 arch/sparc/kernel/head_32.S                 |    4 +-
 arch/sparc/kernel/head_64.S                 |    2 +-
 arch/sparc/kernel/init_task.c               |    2 +-
 arch/sparc/kernel/vmlinux.lds.S             |   14 ++--
 arch/um/include/asm/common.lds.S            |    4 +-
 arch/um/kernel/dyn.lds.S                    |    4 +-
 arch/um/kernel/init_task.c                  |    4 +-
 arch/um/kernel/uml.lds.S                    |    4 +-
 arch/x86/Kconfig                            |    1 +
 arch/x86/boot/compressed/head_32.S          |    2 +-
 arch/x86/boot/compressed/head_64.S          |    2 +-
 arch/x86/boot/compressed/relocs.c           |    2 +-
 arch/x86/boot/compressed/vmlinux.scr        |    2 +-
 arch/x86/boot/compressed/vmlinux_32.lds     |   14 ++-
 arch/x86/boot/compressed/vmlinux_64.lds     |   10 +-
 arch/x86/include/asm/cache.h                |    4 +-
 arch/x86/kernel/acpi/wakeup_32.S            |    2 +-
 arch/x86/kernel/head_32.S                   |    6 +-
 arch/x86/kernel/head_64.S                   |    4 +-
 arch/x86/kernel/init_task.c                 |    4 +-
 arch/x86/kernel/traps.c                     |    2 +-
 arch/x86/kernel/vmlinux_32.lds.S            |   37 ++++---
 arch/x86/kernel/vmlinux_64.lds.S            |   27 +++---
 arch/xtensa/kernel/head.S                   |    2 +-
 arch/xtensa/kernel/init_task.c              |    2 +-
 arch/xtensa/kernel/vmlinux.lds.S            |    6 +-
 include/asm-frv/init.h                      |    8 +-
 include/asm-generic/vmlinux.lds.h           |   19 ++--
 include/linux/cache.h                       |    2 +-
 include/linux/init.h                        |    8 +-
 include/linux/linkage.h                     |    4 +-
 include/linux/percpu.h                      |   10 +-
 include/linux/spinlock.h                    |    2 +-
 kernel/module.c                             |    2 +-
 lib/Kconfig.debug                           |   18 +++
 scripts/mod/file2alias.c                    |    6 +-
 scripts/mod/modpost.c                       |  155 ++++++++++++++++-----------
 scripts/mod/modpost.h                       |   43 ++++++++
 scripts/recordmcount.pl                     |    6 +-
 142 files changed, 515 insertions(+), 409 deletions(-)


^ permalink raw reply	[flat|nested] 9+ messages in thread

end of thread, other threads:[~2009-03-27  1:44 UTC | newest]

Thread overview: 9+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2009-03-24  5:28 [PATCH 0/4] Add support for compiling with -ffunction-sections -fdata-sections Tim Abbott
2009-03-24  5:28 ` [PATCH 1/4] Make section names compatible " Tim Abbott
2009-03-24  5:28   ` [PATCH 2/4] modpost: Check the section flags, not name, to catch missing "ax"/"aw" Tim Abbott
2009-03-24  5:28     ` [PATCH 3/4] modpost: Support objects with more than 64k sections Tim Abbott
2009-03-24  5:28       ` [PATCH 4/4] x86: Add an option to compile with -ffunction-sections -fdata-sections Tim Abbott
2009-03-24  6:07 ` [PATCH 0/4] Add support for compiling " Stephen Rothwell
2009-03-24  7:23   ` Tim Abbott
2009-03-24 14:46     ` H. Peter Anvin
2009-03-27  1:41       ` Tim Abbott

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox