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    x86: make arch/x86/kernel/acpi/wakeup_32.S use a separate · 4c491562
    Eric Dumazet 提交于
    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: NEric Dumazet <dada1@cosmosbay.com>
    Signed-off-by: NIngo Molnar <mingo@elte.hu>
    Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
    4c491562
vmlinux_32.lds.S 5.1 KB