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x86: make arch/x86/kernel/acpi/wakeup_32.S use a separate

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While examining vmlinux namelist on i386 (nm -v vmlinux) I noticed :

c01021d0 t es7000_rename_gsi
c010221a T es7000_start_cpu
<Big Hole>
c0103000 T thread_saved_pc

and

c0113218 T acpi_restore_state_mem
c0113219 T acpi_save_state_mem
<Big Hole>
c0114000 t wakeup_code

This is because arch/x86/kernel/acpi/wakeup_32.S forces a .text alignment
of 4096 bytes. (I have no idea if it is really needed, since
arch/x86/kernel/acpi/wakeup_64.S uses a 16 bytes alignment *only*)

So arch/x86/kernel/built-in.o also has this alignment

arch/x86/kernel/built-in.o:     file format elf32-i386

Sections:
Idx Name          Size      VMA       LMA       File off  Algn
  0 .text         00018c94  00000000  00000000  00001000  2**12
                  CONTENTS, ALLOC, LOAD, RELOC, READONLY, CODE

But as arch/x86/kernel/acpi/wakeup_32.o is not the first object linked
into arch/x86/kernel/built-in.o, linker had to build several holes to meet
alignement requirements, because of .o nestings in the kbuild process.

This can be solved by using a special section, .text.page_aligned, so that
no holes are needed.

# size vmlinux.before vmlinux.after
   text    data     bss     dec     hex filename
4619942  422838  458752 5501532  53f25c vmlinux.before
4610534  422838  458752 5492124  53cd9c vmlinux.after

This saves 9408 bytes

Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This commit is contained in:
Eric Dumazet 2008-01-30 13:32:50 +01:00 committed by Ingo Molnar
parent 0c2bd5a5e3
commit 4c4915627f
2 changed files with 3 additions and 1 deletions
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2
arch/x86/kernel/acpi/wakeup_32.S
View File

@ -1,4 +1,4 @@
.text
.section .text.page_aligned
#include <linux/linkage.h>
#include <asm/segment.h>
#include <asm/page.h>

2
arch/x86/kernel/vmlinux_32.lds.S
View File

@ -38,6 +38,8 @@ SECTIONS
/* read-only */
.text : AT(ADDR(.text) - LOAD_OFFSET) {
. = ALIGN(4096); /* not really needed, already page aligned */
*(.text.page_aligned)
TEXT_TEXT
SCHED_TEXT
LOCK_TEXT