Subject: [RFC PATCH v3 0/13] memory-hotplug : hot-remove physical memory

From: Yasuaki Ishimatsu <[email-masked]>
Date: Mon, 9 Jul 2012 19:21:22 +0900

This patch series aims to support physical memory hot-remove.

  [RFC PATCH v3 1/13] memory-hotplug : rename remove_memory to offline_memory
  [RFC PATCH v3 2/13] memory-hotplug : add physical memory hotplug code to acpi_memory_device_remove
  [RFC PATCH v3 3/13] memory-hotplug : unify argument of firmware_map_add_early/hotplug
  [RFC PATCH v3 4/13] memory-hotplug : remove /sys/firmware/memmap/X sysfs
  [RFC PATCH v3 5/13] memory-hotplug : does not release memory region in PAGES_PER_SECTION chunks
  [RFC PATCH v3 6/13] memory-hotplug : add memory_block_release
  [RFC PATCH v3 7/13] memory-hotplug : remove_memory calls __remove_pages
  [RFC PATCH v3 8/13] memory-hotplug : check page type in get_page_bootmem
  [RFC PATCH v3 9/13] memory-hotplug : move register_page_bootmem_info_node and put_page_bootmem for
sparse-vmemmap
  [RFC PATCH v3 10/13] memory-hotplug : implement register_page_bootmem_info_section of sparse-vmemmap
  [RFC PATCH v3 11/13] memory-hotplug : free memmap of sparse-vmemmap
  [RFC PATCH v3 12/13] memory-hotplug : add node_device_release
  [RFC PATCH v3 13/13] memory-hotplug : remove sysfs file of node

Even if you apply these patches, you cannot remove the physical memory
completely since these patches are still under development. I want you to
cooperate to improve the physical memory hot-remove. So please review these
patches and give your comment/idea.

The patches can free/remove following things:

  - acpi_memory_info                          : [RFC PATCH 2/13]
  - /sys/firmware/memmap/X/{end, start, type} : [RFC PATCH 4/13]
  - iomem_resource                            : [RFC PATCH 5/13]
  - mem_section and related sysfs files       : [RFC PATCH 6-11/13]
  - node and related sysfs files              : [RFC PATCH 12-13/13]

The patches cannot do following things yet:

  - page table of removed memory

If you find lack of function for physical memory hot-remove, please let me
know.

change log of v3:
 * rebase to 3.5.0-rc6

 [RFC PATCH v2 2/13]
   * remove extra kobject_put()

   * The patch was commented by Wen. Wen's comment is
     "acpi_memory_device_remove() should ignore a return value of
     remove_memory() since caller does not care the return value".
     But I did not change it since I think caller should care the
     return value. And I am trying to fix it as follow:

     https://lkml.org/lkml/2012/7/5/624

 [RFC PATCH v2 4/13]
   * remove a firmware_memmap_entry allocated by kzmalloc()

change log of v2:
 [RFC PATCH v2 2/13]
   * check whether memory block is offline or not before calling offline_memory()
   * check whether section is valid or not in is_memblk_offline()
   * call kobject_put() for each memory_block in is_memblk_offline()

 [RFC PATCH v2 3/13]
   * unify the end argument of firmware_map_add_early/hotplug

 [RFC PATCH v2 4/13]
   * add release_firmware_map_entry() for freeing firmware_map_entry

 [RFC PATCH v2 6/13]
  * add release_memory_block() for freeing memory_block

 [RFC PATCH v2 11/13]
  * fix wrong arguments of free_pages()

---
 arch/powerpc/platforms/pseries/hotplug-memory.c |   16 +-
 arch/x86/mm/init_64.c                           |  144 ++++++++++++++++++++++++
 drivers/acpi/acpi_memhotplug.c                  |   28 ++++
 drivers/base/memory.c                           |   54 ++++++++-
 drivers/base/node.c                             |    7 +
 drivers/firmware/memmap.c                       |   78 ++++++++++++-
 include/linux/firmware-map.h                    |    6 +
 include/linux/memory.h                          |    5
 include/linux/memory_hotplug.h                  |   17 --
 include/linux/mm.h                              |    5
 mm/memory_hotplug.c                             |   98 ++++++++++++----
 mm/sparse.c                                     |    5
 12 files changed, 414 insertions(+), 49 deletions(-)