[RFC PATCH v2, part4 00/39] Simplify mem_init() implementations and kill num_physpages

[Jiang Liu <liuj97@gmail.com>]

The original goal of this patchset is to fix the bug reported by
https://bugzilla.kernel.org/show_bug.cgi?id=53501
Now it has also been expanded to reduce common code used by memory
initializion.

This is the last part, previous three patch sets could be accessed at:
http://marc.info/?l=linux-mm&m=136289696323825&w=2
http://marc.info/?l=linux-mm&m=136290291524901&w=2
http://marc.info/?l=linux-mm&m=136345342831592&w=2

This patchset applies to
https://git.kernel.org/pub/scm/linux/kernel/git/mhocko/mm.git since-3.8

Patch 1-7: 
	1) add comments for global variables exported by vmlinux.lds
	2) normalize global variables exported by vmlinux.lds
Patch 8:
	Introduce helper functions mem_init_print_info() and
	get_num_physpages()
Patch 9:
	Avoid using num_physpages at runtime
Patch 10-38:
	1) Simplify mem_init() by using mem_init_print_info()
	2) Prepare fore kill global variable num_physpages
Patch 39:
	Kill global variable num_physpages

With all patches applied, mem_init(), free_initmem(), free_initrd_mem()
could be as simple as below. This patch series has reduced about 1.2K
lines of code in total.

#ifndef CONFIG_DISCONTIGMEM
void __init
mem_init(void)
{
	max_mapnr = max_low_pfn;
	free_all_bootmem();
	high_memory = (void *) __va(max_low_pfn * PAGE_SIZE);

	mem_init_print_info(NULL);
}
#endif /* CONFIG_DISCONTIGMEM */

void
free_initmem(void)
{
	free_initmem_default(-1);
}

#ifdef CONFIG_BLK_DEV_INITRD
void
free_initrd_mem(unsigned long start, unsigned long end)
{
	free_reserved_area(start, end, -1, "initrd");
}
#endif

Due to hardware resource limitations, I have only tested this on x86_64.
And the messages reported are:
Previous log message:
Memory: 7745676k/8910848k available (6934k kernel code, 836024k absent, 329148k reserved, 6343k data, 1012k init)
Current log message:
Memory: 7744624K/8074824K available (6969K kernel code, 1011K data, 2828K rodata, 1016K init, 9640K bss, 330200K reserved)

Any help to review or test these patch series are welcomed!

Jiang Liu (39):
  vmlinux.lds: add comments for global variables and clean up useless
    declarations
  avr32: normalize global variables exported by vmlinux.lds
  c6x: normalize global variables exported by vmlinux.lds
  h8300: normalize global variables exported by vmlinux.lds
  score: normalize global variables exported by vmlinux.lds
  tile: normalize global variables exported by vmlinux.lds
  UML: normalize global variables exported by vmlinux.lds
  mm: introduce helper function mem_init_print_info() to simplify
    mem_init()
  mm: use totalram_pages instead of num_physpages at runtime
  mm/alpha: prepare for removing num_physpages and simplify mem_init()
  mm/ARM: prepare for removing num_physpages and simplify mem_init()
  mm/ARM64: prepare for removing num_physpages and simplify mem_init()
  mm/AVR32: prepare for removing num_physpages and simplify mem_init()
  mm/blackfin: prepare for removing num_physpages and simplify
    mem_init()
  mm/c6x: prepare for removing num_physpages and simplify mem_init()
  mm/cris: prepare for removing num_physpages and simplify mem_init()
  mm/frv: prepare for removing num_physpages and simplify mem_init()
  mm/h8300: prepare for removing num_physpages and simplify mem_init()
  mm/hexagon: prepare for removing num_physpages and simplify
    mem_init()
  mm/IA64: prepare for removing num_physpages and simplify mem_init()
  mm/m32r: prepare for removing num_physpages and simplify mem_init()
  mm/m68k: prepare for removing num_physpages and simplify mem_init()
  mm/microblaze: prepare for removing num_physpages and simplify
    mem_init()
  mm/MIPS: prepare for removing num_physpages and simplify mem_init()
  mm/mn10300: prepare for removing num_physpages and simplify
    mem_init()
  mm/openrisc: prepare for removing num_physpages and simplify
    mem_init()
  mm/PARISC: prepare for removing num_physpages and simplify mem_init()
  mm/ppc: prepare for removing num_physpages and simplify mem_init()
  mm/s390: prepare for removing num_physpages and simplify mem_init()
  mm/score: prepare for removing num_physpages and simplify mem_init()
  mm/SH: prepare for removing num_physpages and simplify mem_init()
  mm/SPARC: prepare for removing num_physpages and simplify mem_init()
  mm/tile: prepare for removing num_physpages and simplify mem_init()
  mm/um: prepare for removing num_physpages and simplify mem_init()
  mm/unicore32: prepare for removing num_physpages and simplify
    mem_init()
  mm/x86: prepare for removing num_physpages and simplify mem_init()
  mm/xtensa: prepare for removing num_physpages and simplify mem_init()
  mm/hotplug: prepare for removing num_physpages
  mm: kill global variable num_physpages

 arch/alpha/mm/init.c              |   32 ++-------------------
 arch/alpha/mm/numa.c              |   34 ++++------------------
 arch/arm/mm/init.c                |   47 ++----------------------------
 arch/arm64/mm/init.c              |   48 ++-----------------------------
 arch/avr32/kernel/setup.c         |    2 +-
 arch/avr32/kernel/vmlinux.lds.S   |    4 +--
 arch/avr32/mm/init.c              |   29 +++----------------
 arch/blackfin/mm/init.c           |   38 ++++---------------------
 arch/c6x/kernel/vmlinux.lds.S     |    4 +--
 arch/c6x/mm/init.c                |   11 +------
 arch/cris/mm/init.c               |   33 ++-------------------
 arch/frv/kernel/setup.c           |   14 ++++-----
 arch/frv/mm/init.c                |   49 +++++++++----------------------
 arch/h8300/boot/compressed/misc.c |    1 -
 arch/h8300/kernel/vmlinux.lds.S   |    2 ++
 arch/h8300/mm/init.c              |   34 ++++++----------------
 arch/hexagon/mm/init.c            |    3 +-
 arch/ia64/mm/contig.c             |   11 -------
 arch/ia64/mm/discontig.c          |    3 --
 arch/ia64/mm/init.c               |   27 +-----------------
 arch/m32r/mm/discontig.c          |    6 +---
 arch/m32r/mm/init.c               |   49 ++++---------------------------
 arch/m68k/mm/init.c               |   31 ++------------------
 arch/microblaze/mm/init.c         |   51 ++++-----------------------------
 arch/mips/mm/init.c               |   57 ++++++++++++-------------------------
 arch/mips/pci/pci-lantiq.c        |    2 +-
 arch/mips/sgi-ip27/ip27-memory.c  |   21 ++------------
 arch/mn10300/mm/init.c            |   26 ++---------------
 arch/openrisc/mm/init.c           |   44 +++-------------------------
 arch/parisc/mm/init.c             |   46 ++----------------------------
 arch/powerpc/mm/mem.c             |   56 ++++++++----------------------------
 arch/s390/mm/init.c               |   17 ++---------
 arch/score/kernel/vmlinux.lds.S   |    1 +
 arch/score/mm/init.c              |   26 ++---------------
 arch/sh/mm/init.c                 |   25 +++-------------
 arch/sparc/kernel/leon_smp.c      |    3 --
 arch/sparc/mm/init_32.c           |   33 ++-------------------
 arch/sparc/mm/init_64.c           |   27 ++----------------
 arch/tile/include/asm/sections.h  |    2 +-
 arch/tile/kernel/setup.c          |   20 ++++++-------
 arch/tile/kernel/vmlinux.lds.S    |    4 ++-
 arch/tile/mm/init.c               |   17 ++---------
 arch/um/include/asm/common.lds.S  |    1 -
 arch/um/kernel/dyn.lds.S          |    6 ++--
 arch/um/kernel/mem.c              |    4 +--
 arch/um/kernel/uml.lds.S          |    7 +++--
 arch/unicore32/mm/init.c          |   49 ++-----------------------------
 arch/x86/kernel/cpu/amd.c         |    2 +-
 arch/x86/kernel/setup.c           |    2 --
 arch/x86/mm/init_32.c             |   30 ++-----------------
 arch/x86/mm/init_64.c             |   20 +------------
 arch/x86/mm/numa_32.c             |    2 --
 arch/xtensa/mm/init.c             |   27 ++----------------
 fs/fuse/inode.c                   |    2 +-
 include/asm-generic/sections.h    |   21 +++++++++++++-
 include/linux/mm.h                |   13 ++++++++-
 kernel/power/snapshot.c           |    4 +--
 mm/memory.c                       |    2 --
 mm/memory_hotplug.c               |    4 ---
 mm/nommu.c                        |    2 --
 mm/page_alloc.c                   |   52 +++++++++++++++++++++++++++++++++
 net/ipv4/inet_fragment.c          |    2 +-
 62 files changed, 256 insertions(+), 986 deletions(-)

-- 
1.7.9.5

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