Hi Andrew,

The patch-set aims to linux-3.8. So we would like you to merge
the patch-set into your tree.

The patch-set applied many comments. Currently there is no
comment to the patch-set.

Additionally, we have spent a lot of time on the verification
of the patch-set. And we found many bugs, and fixed them.

So we believe that Linux on x86_64 can support memory hot remove
by the patch-set. 

Thanks,
Yasuaki Ishimatsu

2012/11/01 18:44, Wen Congyang wrote:

The patch-set was divided from following thread's patch-set.
     https://lkml.org/lkml/2012/9/5/201

The last version of this patchset:
     https://lkml.org/lkml/2012/10/23/213

If you want to know the reason, please read following thread.

https://lkml.org/lkml/2012/10/2/83

The patch-set has only the function of kernel core side for physical
memory hot remove. So if you use the patch, please apply following
patches.

- bug fix for memory hot remove
   https://lkml.org/lkml/2012/10/31/269
   
- acpi framework
   https://lkml.org/lkml/2012/10/26/175

The patches can free/remove the following things:

   - /sys/firmware/memmap/X/{end, start, type} : [PATCH 2/10]
   - mem_section and related sysfs files       : [PATCH 3-4/10]
   - memmap of sparse-vmemmap                  : [PATCH 5-7/10]
   - page table of removed memory              : [RFC PATCH 8/10]
   - node and related sysfs files              : [RFC PATCH 9-10/10]

* [PATCH 2/10] checks whether the memory can be removed or not.

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

How to test this patchset?
1. apply this patchset and build the kernel. MEMORY_HOTPLUG, MEMORY_HOTREMOVE,
    ACPI_HOTPLUG_MEMORY must be selected.
2. load the module acpi_memhotplug
3. hotplug the memory device(it depends on your hardware)
    You will see the memory device under the directory /sys/bus/acpi/devices/.
    Its name is PNP0C80:XX.
4. online/offline pages provided by this memory device
    You can write online/offline to /sys/devices/system/memory/memoryX/state to
    online/offline pages provided by this memory device
5. hotremove the memory device
    You can hotremove the memory device by the hardware, or writing 1 to
    /sys/bus/acpi/devices/PNP0C80:XX/eject.

Note: if the memory provided by the memory device is used by the kernel, it
can't be offlined. It is not a bug.

Known problems:
1. hotremoving memory device may cause kernel panicked
    This bug will be fixed by Liu Jiang's patch:
    https://lkml.org/lkml/2012/7/3/1


Changelogs from v2 to v3:
  Patch9: call sync_global_pgds() if pgd is changed
  Patch10: fix a problem int the patch

Changelogs from v1 to v2:
  Patch1: new patch, offline memory twice. 1st iterate: offline every non primary
          memory block. 2nd iterate: offline primary (i.e. first added) memory
          block.

  Patch3: new patch, no logical change, just remove reduntant codes.

  Patch9: merge the patch from wujianguo into this patch. flush tlb on all cpu
          after the pagetable is changed.

  Patch12: new patch, free node_data when a node is offlined

Wen Congyang (6):
   memory-hotplug: try to offline the memory twice to avoid dependence
   memory-hotplug: remove redundant codes
   memory-hotplug: introduce new function arch_remove_memory() for
     removing page table depends on architecture
   memory-hotplug: remove page table of x86_64 architecture
   memory-hotplug: remove sysfs file of node
   memory-hotplug: free node_data when a node is offlined

Yasuaki Ishimatsu (6):
   memory-hotplug: check whether all memory blocks are offlined or not
     when removing memory
   memory-hotplug: remove /sys/firmware/memmap/X sysfs
   memory-hotplug: unregister memory section on SPARSEMEM_VMEMMAP
   memory-hotplug: implement register_page_bootmem_info_section of
     sparse-vmemmap
   memory-hotplug: remove memmap of sparse-vmemmap
   memory-hotplug: memory_hotplug: clear zone when removing the memory

  arch/ia64/mm/discontig.c             |  14 ++
  arch/ia64/mm/init.c                  |  18 ++
  arch/powerpc/mm/init_64.c            |  14 ++
  arch/powerpc/mm/mem.c                |  12 +
  arch/s390/mm/init.c                  |  12 +
  arch/s390/mm/vmem.c                  |  14 ++
  arch/sh/mm/init.c                    |  17 ++
  arch/sparc/mm/init_64.c              |  14 ++
  arch/tile/mm/init.c                  |   8 +
  arch/x86/include/asm/pgtable_types.h |   1 +
  arch/x86/mm/init_32.c                |  12 +
  arch/x86/mm/init_64.c                | 417 +++++++++++++++++++++++++++++++++++
  arch/x86/mm/pageattr.c               |  47 ++--
  drivers/acpi/acpi_memhotplug.c       |   8 +-
  drivers/base/memory.c                |   6 +
  drivers/firmware/memmap.c            |  98 +++++++-
  include/linux/firmware-map.h         |   6 +
  include/linux/memory_hotplug.h       |  15 +-
  include/linux/mm.h                   |   5 +-
  mm/memory_hotplug.c                  | 409 ++++++++++++++++++++++++++++++++--
  mm/sparse.c                          |   5 +-
  21 files changed, 1095 insertions(+), 57 deletions(-)