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Message-ID: <506A2F2B.8060204@jp.fujitsu.com>
Date: Tue, 2 Oct 2012 09:02:51 +0900
From: Yasuaki Ishimatsu <isimatu.yasuaki@...fujitsu.com>
To: Ni zhan Chen <nizhan.chen@...il.com>
CC: <wency@...fujitsu.com>, <x86@...nel.org>, <linux-mm@...ck.org>,
<linux-kernel@...r.kernel.org>, <linuxppc-dev@...ts.ozlabs.org>,
<linux-acpi@...r.kernel.org>, <linux-s390@...r.kernel.org>,
<linux-sh@...r.kernel.org>, <linux-ia64@...r.kernel.org>,
<cmetcalf@...era.com>, <sparclinux@...r.kernel.org>,
<rientjes@...gle.com>, <liuj97@...il.com>, <len.brown@...el.com>,
<benh@...nel.crashing.org>, <paulus@...ba.org>, <cl@...ux.com>,
<minchan.kim@...il.com>, <akpm@...ux-foundation.org>,
<kosaki.motohiro@...fujitsu.com>
Subject: Re: [RFC v9 PATCH 00/21] memory-hotplug: hot-remove physical memory
Hi Chen,
2012/10/02 8:45, Ni zhan Chen wrote:
> On 10/01/2012 12:44 PM, Yasuaki Ishimatsu wrote:
>> Hi Chen,
>>
>> 2012/09/29 17:19, Ni zhan Chen wrote:
>>> On 09/05/2012 05:25 PM, wency@...fujitsu.com wrote:
>>>> From: Wen Congyang <wency@...fujitsu.com>
>>>>
>>>> This patch series aims to support physical memory hot-remove.
>>>>
>>>> The patches can free/remove the following things:
>>>>
>>>> - acpi_memory_info : [RFC PATCH 4/19]
>>>> - /sys/firmware/memmap/X/{end, start, type} : [RFC PATCH 8/19]
>>>> - iomem_resource : [RFC PATCH 9/19]
>>>> - mem_section and related sysfs files : [RFC PATCH 10-11, 13-16/19]
>>>> - page table of removed memory : [RFC PATCH 12/19]
>>>> - node and related sysfs files : [RFC PATCH 18-19/19]
>>>>
>>>> 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
>>>
>>> Hi Yasuaki,
>>>
>>> where is the acpi_memhotplug module?
>>
>> If you build acpi_memhotplug as module, it is created under
>> /lib/modules/<kernel-version>/driver/acpi/ directory. It depends
>> on config ACPI_HOTPLUG_MEMORY. The confing is [*], it becomes built-in
>> function. So you don't need to care about it.
>> Thanks,
>> Yasuaki Ishimatsu
>
> Hi Yasuaki,
>
> I build the kernel, MEMORY_HOTPLUG, MEMORY_HOTREMOVE, ACPI_HOTPLUG_MEMORY are seleted as [*], but I can't find PNP0C80:XX under the directory /sys/bus/acpi/devices/.
>
> [root@...alhost ~]# ls /sys/bus/acpi/devices/
> device:00 device:07 device:0e device:15 device:1c device:23 device:2a LNXCPU:00 LNXCPU:07 PNP0501:00 PNP0C02:00 PNP0C0F:02 PNP0C14:01
> device:01 device:08 device:0f device:16 device:1d device:24 device:2b LNXCPU:01 LNXPWRBN:00 PNP0800:00 PNP0C02:01 PNP0C0F:03 PNP0C31:00
> device:02 device:09 device:10 device:17 device:1e device:25 device:2c LNXCPU:02 LNXSYSTM:00 PNP0A08:00 PNP0C02:02 PNP0C0F:04
> device:03 device:0a device:11 device:18 device:1f device:26 device:2d LNXCPU:03 PNP0000:00 PNP0B00:00 PNP0C04:00 PNP0C0F:05
> device:04 device:0b device:12 device:19 device:20 device:27 device:2e LNXCPU:04 PNP0100:00 PNP0C01:00 PNP0C0C:00 PNP0C0F:06
> device:05 device:0c device:13 device:1a device:21 device:28 device:2f LNXCPU:05 PNP0103:00 PNP0C01:01 PNP0C0F:00 PNP0C0F:07
> device:06 device:0d device:14 device:1b device:22 device:29 INT3F0D:00 LNXCPU:06 PNP0200:00 PNP0C01:02 PNP0C0F:01 PNP0C14:00
>
> then what I miss ? thanks.
It depend on hardware. It seems that your system does not support
memory hotplug. If you use KVM, you can try memory hotplug on KVM
guest by applying Vasilis' patch-set.
http://lists.gnu.org/archive/html/qemu-devel/2012-07/msg01389.html
Thanks,
Yasuaki Ishimatsu
>
>>
>>>
>>>> 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. memory can't be offlined when CONFIG_MEMCG is selected.
>>>> For example: there is a memory device on node 1. The address range
>>>> is [1G, 1.5G). You will find 4 new directories memory8, memory9, memory10,
>>>> and memory11 under the directory /sys/devices/system/memory/.
>>>> If CONFIG_MEMCG is selected, we will allocate memory to store page cgroup
>>>> when we online pages. When we online memory8, the memory stored page cgroup
>>>> is not provided by this memory device. But when we online memory9, the memory
>>>> stored page cgroup may be provided by memory8. So we can't offline memory8
>>>> now. We should offline the memory in the reversed order.
>>>> When the memory device is hotremoved, we will auto offline memory provided
>>>> by this memory device. But we don't know which memory is onlined first, so
>>>> offlining memory may fail. In such case, you should offline the memory by
>>>> hand before hotremoving the memory device.
>>>> 2. 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
>>>>
>>>> change log of v9:
>>>> [RFC PATCH v9 8/21]
>>>> * add a lock to protect the list map_entries
>>>> * add an indicator to firmware_map_entry to remember whether the memory
>>>> is allocated from bootmem
>>>> [RFC PATCH v9 10/21]
>>>> * change the macro to inline function
>>>> [RFC PATCH v9 19/21]
>>>> * don't offline the node if the cpu on the node is onlined
>>>> [RFC PATCH v9 21/21]
>>>> * create new patch: auto offline page_cgroup when onlining memory block
>>>> failed
>>>>
>>>> change log of v8:
>>>> [RFC PATCH v8 17/20]
>>>> * Fix problems when one node's range include the other nodes
>>>> [RFC PATCH v8 18/20]
>>>> * fix building error when CONFIG_MEMORY_HOTPLUG_SPARSE or CONFIG_HUGETLBFS
>>>> is not defined.
>>>> [RFC PATCH v8 19/20]
>>>> * don't offline node when some memory sections are not removed
>>>> [RFC PATCH v8 20/20]
>>>> * create new patch: clear hwpoisoned flag when onlining pages
>>>>
>>>> change log of v7:
>>>> [RFC PATCH v7 4/19]
>>>> * do not continue if acpi_memory_device_remove_memory() fails.
>>>> [RFC PATCH v7 15/19]
>>>> * handle usemap in register_page_bootmem_info_section() too.
>>>>
>>>> change log of v6:
>>>> [RFC PATCH v6 12/19]
>>>> * fix building error on other archtitectures than x86
>>>>
>>>> [RFC PATCH v6 15-16/19]
>>>> * fix building error on other archtitectures than x86
>>>>
>>>> change log of v5:
>>>> * merge the patchset to clear page table and the patchset to hot remove
>>>> memory(from ishimatsu) to one big patchset.
>>>>
>>>> [RFC PATCH v5 1/19]
>>>> * rename remove_memory() to offline_memory()/offline_pages()
>>>>
>>>> [RFC PATCH v5 2/19]
>>>> * new patch: implement offline_memory(). This function offlines pages,
>>>> update memory block's state, and notify the userspace that the memory
>>>> block's state is changed.
>>>>
>>>> [RFC PATCH v5 4/19]
>>>> * offline and remove memory in acpi_memory_disable_device() too.
>>>>
>>>> [RFC PATCH v5 17/19]
>>>> * new patch: add a new function __remove_zone() to revert the things done
>>>> in the function __add_zone().
>>>>
>>>> [RFC PATCH v5 18/19]
>>>> * flush work befor reseting node device.
>>>>
>>>> change log of v4:
>>>> * remove "memory-hotplug : unify argument of firmware_map_add_early/hotplug"
>>>> from the patch series, since the patch is a bugfix. It is being disccussed
>>>> on other thread. But for testing the patch series, the patch is needed.
>>>> So I added the patch as [PATCH 0/13].
>>>>
>>>> [RFC PATCH v4 2/13]
>>>> * check memory is online or not at remove_memory()
>>>> * add memory_add_physaddr_to_nid() to acpi_memory_device_remove() for
>>>> getting node id
>>>> [RFC PATCH v4 3/13]
>>>> * create new patch : check memory is online or not at online_pages()
>>>>
>>>> [RFC PATCH v4 4/13]
>>>> * add __ref section to remove_memory()
>>>> * call firmware_map_remove_entry() before remove_sysfs_fw_map_entry()
>>>>
>>>> [RFC PATCH v4 11/13]
>>>> * rewrite register_page_bootmem_memmap() for removing page used as PT/PMD
>>>>
>>>> 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()
>>>>
>>>>
>>>> Wen Congyang (8):
>>>> memory-hotplug: implement offline_memory()
>>>> memory-hotplug: store the node id in acpi_memory_device
>>>> memory-hotplug: export the function acpi_bus_remove()
>>>> memory-hotplug: call acpi_bus_remove() to remove memory device
>>>> memory-hotplug: introduce new function arch_remove_memory()
>>>> memory-hotplug: remove sysfs file of node
>>>> memory-hotplug: clear hwpoisoned flag when onlining pages
>>>> memory-hotplug: auto offline page_cgroup when onlining memory block
>>>> failed
>>>>
>>>> Yasuaki Ishimatsu (13):
>>>> memory-hotplug: rename remove_memory() to
>>>> offline_memory()/offline_pages()
>>>> memory-hotplug: offline and remove memory when removing the memory
>>>> device
>>>> memory-hotplug: check whether memory is present or not
>>>> memory-hotplug: remove /sys/firmware/memmap/X sysfs
>>>> memory-hotplug: does not release memory region in PAGES_PER_SECTION
>>>> chunks
>>>> memory-hotplug: add memory_block_release
>>>> memory-hotplug: remove_memory calls __remove_pages
>>>> memory-hotplug: check page type in get_page_bootmem
>>>> memory-hotplug: move register_page_bootmem_info_node and
>>>> put_page_bootmem for sparse-vmemmap
>>>> memory-hotplug: implement register_page_bootmem_info_section of
>>>> sparse-vmemmap
>>>> memory-hotplug: free memmap of sparse-vmemmap
>>>> memory_hotplug: clear zone when the memory is removed
>>>> memory-hotplug: add node_device_release
>>>>
>>>> arch/ia64/mm/discontig.c | 14 +
>>>> arch/ia64/mm/init.c | 16 +
>>>> arch/powerpc/mm/init_64.c | 14 +
>>>> arch/powerpc/mm/mem.c | 14 +
>>>> arch/powerpc/platforms/pseries/hotplug-memory.c | 16 +-
>>>> arch/s390/mm/init.c | 12 +
>>>> arch/s390/mm/vmem.c | 14 +
>>>> arch/sh/mm/init.c | 15 +
>>>> 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 | 10 +
>>>> arch/x86/mm/init_64.c | 331 ++++++++++++++++++
>>>> arch/x86/mm/pageattr.c | 47 ++--
>>>> drivers/acpi/acpi_memhotplug.c | 54 +++-
>>>> drivers/acpi/scan.c | 3 +-
>>>> drivers/base/memory.c | 88 ++++-
>>>> drivers/base/node.c | 11 +
>>>> drivers/firmware/memmap.c | 98 +++++-
>>>> include/acpi/acpi_bus.h | 1 +
>>>> include/linux/firmware-map.h | 6 +
>>>> include/linux/memory.h | 5 +
>>>> include/linux/memory_hotplug.h | 25 +-
>>>> include/linux/mm.h | 5 +-
>>>> include/linux/mmzone.h | 19 +
>>>> mm/memory_hotplug.c | 424 +++++++++++++++++++++--
>>>> mm/page_cgroup.c | 3 +
>>>> mm/sparse.c | 5 +-
>>>> 28 files changed, 1181 insertions(+), 92 deletions(-)
>>>>
>>>> --
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>>>>
>>>
>>
>>
>>
>
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