[PATCH v5 00/14] memory-hotplug: hot-remove physical memory

From: Tang Chen
Date: Mon Dec 24 2012 - 07:13:33 EST


Hi Andrew,

Here is the physical memory hot-remove patch-set based on 3.8rc-1.

This patch-set aims to implement physical memory hot-removing.

The patches can free/remove the following things:

- /sys/firmware/memmap/X/{end, start, type} : [PATCH 4/14]
- memmap of sparse-vmemmap : [PATCH 6,7,8,10/14]
- page table of removed memory : [RFC PATCH 7,8,10/14]
- node and related sysfs files : [RFC PATCH 13-14/14]


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.


Changelogs from v4 to v5:
Patch7: new patch, move pgdat_resize_lock into sparse_remove_one_section() to
avoid disabling irq because we need flush tlb when free pagetables.
Patch8: new patch, pick up some common APIs that are used to free direct mapping
and vmemmap pagetables.
Patch9: free direct mapping pagetables on x86_64 arch.
Patch10: free vmemmap pagetables.
Patch11: since freeing memmap with vmemmap has been implemented, the config
macro CONFIG_SPARSEMEM_VMEMMAP when defining __remove_section() is
no longer needed.
Patch13: no need to modify acpi_memory_disable_device() since it was removed,
and add nid parameter when calling remove_memory().

Changelogs from v3 to v4:
Patch7: remove unused codes.
Patch8: fix nr_pages that is passed to free_map_bootmem()

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.


Tang Chen (5):
memory-hotplug: move pgdat_resize_lock into
sparse_remove_one_section()
memory-hotplug: remove page table of x86_64 architecture
memory-hotplug: remove memmap of sparse-vmemmap
memory-hotplug: Integrated __remove_section() of
CONFIG_SPARSEMEM_VMEMMAP.
memory-hotplug: remove sysfs file of node

Wen Congyang (5):
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: Common APIs to support page tables hot-remove
memory-hotplug: free node_data when a node is offlined

Yasuaki Ishimatsu (4):
memory-hotplug: check whether all memory blocks are offlined or not
when removing memory
memory-hotplug: remove /sys/firmware/memmap/X sysfs
memory-hotplug: implement register_page_bootmem_info_section of
sparse-vmemmap
memory-hotplug: memory_hotplug: clear zone when removing the memory

arch/arm64/mm/mmu.c | 3 +
arch/ia64/mm/discontig.c | 10 +
arch/ia64/mm/init.c | 18 ++
arch/powerpc/mm/init_64.c | 10 +
arch/powerpc/mm/mem.c | 12 +
arch/s390/mm/init.c | 12 +
arch/s390/mm/vmem.c | 10 +
arch/sh/mm/init.c | 17 ++
arch/sparc/mm/init_64.c | 10 +
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 | 382 ++++++++++++++++++++++++++++++++
arch/x86/mm/pageattr.c | 47 ++--
drivers/acpi/acpi_memhotplug.c | 8 +-
drivers/base/memory.c | 6 +
drivers/firmware/memmap.c | 98 ++++++++-
include/linux/bootmem.h | 1 +
include/linux/firmware-map.h | 6 +
include/linux/memory_hotplug.h | 15 +-
include/linux/mm.h | 4 +-
mm/memory_hotplug.c | 406 ++++++++++++++++++++++++++++++++--
mm/sparse.c | 8 +-
23 files changed, 1043 insertions(+), 61 deletions(-)

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