ed2f240094
Currently memory-hotplug has two limits: 1. If the memory block is in ZONE_NORMAL, you can change it to ZONE_MOVABLE, but this memory block must be adjacent to ZONE_MOVABLE. 2. If the memory block is in ZONE_MOVABLE, you can change it to ZONE_NORMAL, but this memory block must be adjacent to ZONE_NORMAL. With this patch, we can easy to know a memory block can be onlined to which zone, and don't need to know the above two limits. Updated the related Documentation. [akpm@linux-foundation.org: use conventional comment layout] [akpm@linux-foundation.org: fix build with CONFIG_MEMORY_HOTREMOVE=n] [akpm@linux-foundation.org: remove unused local zone_prev] Signed-off-by: Zhang Zhen <zhenzhang.zhang@huawei.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: David Rientjes <rientjes@google.com> Cc: Toshi Kani <toshi.kani@hp.com> Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Wang Nan <wangnan0@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
93 lines
3.6 KiB
Text
93 lines
3.6 KiB
Text
What: /sys/devices/system/memory
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Date: June 2008
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Contact: Badari Pulavarty <pbadari@us.ibm.com>
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Description:
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The /sys/devices/system/memory contains a snapshot of the
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internal state of the kernel memory blocks. Files could be
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added or removed dynamically to represent hot-add/remove
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operations.
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Users: hotplug memory add/remove tools
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http://www.ibm.com/developerworks/wikis/display/LinuxP/powerpc-utils
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What: /sys/devices/system/memory/memoryX/removable
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Date: June 2008
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Contact: Badari Pulavarty <pbadari@us.ibm.com>
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Description:
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The file /sys/devices/system/memory/memoryX/removable
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indicates whether this memory block is removable or not.
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This is useful for a user-level agent to determine
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identify removable sections of the memory before attempting
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potentially expensive hot-remove memory operation
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Users: hotplug memory remove tools
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http://www.ibm.com/developerworks/wikis/display/LinuxP/powerpc-utils
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What: /sys/devices/system/memory/memoryX/phys_device
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Date: September 2008
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Contact: Badari Pulavarty <pbadari@us.ibm.com>
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Description:
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The file /sys/devices/system/memory/memoryX/phys_device
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is read-only and is designed to show the name of physical
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memory device. Implementation is currently incomplete.
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What: /sys/devices/system/memory/memoryX/phys_index
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Date: September 2008
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Contact: Badari Pulavarty <pbadari@us.ibm.com>
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Description:
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The file /sys/devices/system/memory/memoryX/phys_index
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is read-only and contains the section ID in hexadecimal
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which is equivalent to decimal X contained in the
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memory section directory name.
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What: /sys/devices/system/memory/memoryX/state
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Date: September 2008
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Contact: Badari Pulavarty <pbadari@us.ibm.com>
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Description:
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The file /sys/devices/system/memory/memoryX/state
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is read-write. When read, its contents show the
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online/offline state of the memory section. When written,
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root can toggle the the online/offline state of a removable
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memory section (see removable file description above)
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using the following commands.
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# echo online > /sys/devices/system/memory/memoryX/state
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# echo offline > /sys/devices/system/memory/memoryX/state
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For example, if /sys/devices/system/memory/memory22/removable
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contains a value of 1 and
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/sys/devices/system/memory/memory22/state contains the
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string "online" the following command can be executed by
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by root to offline that section.
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# echo offline > /sys/devices/system/memory/memory22/state
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Users: hotplug memory remove tools
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http://www.ibm.com/developerworks/wikis/display/LinuxP/powerpc-utils
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What: /sys/devices/system/memory/memoryX/valid_zones
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Date: July 2014
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Contact: Zhang Zhen <zhenzhang.zhang@huawei.com>
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Description:
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The file /sys/devices/system/memory/memoryX/valid_zones is
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read-only and is designed to show which zone this memory
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block can be onlined to.
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What: /sys/devices/system/memoryX/nodeY
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Date: October 2009
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Contact: Linux Memory Management list <linux-mm@kvack.org>
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Description:
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When CONFIG_NUMA is enabled, a symbolic link that
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points to the corresponding NUMA node directory.
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For example, the following symbolic link is created for
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memory section 9 on node0:
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/sys/devices/system/memory/memory9/node0 -> ../../node/node0
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What: /sys/devices/system/node/nodeX/memoryY
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Date: September 2008
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Contact: Gary Hade <garyhade@us.ibm.com>
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Description:
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When CONFIG_NUMA is enabled
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/sys/devices/system/node/nodeX/memoryY is a symbolic link that
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points to the corresponding /sys/devices/system/memory/memoryY
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memory section directory. For example, the following symbolic
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link is created for memory section 9 on node0.
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/sys/devices/system/node/node0/memory9 -> ../../memory/memory9
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