• Alex Chiang's avatar
    mm: add numa node symlink for memory section in sysfs · dee5d0d5
    Alex Chiang authored
    Commit c04fc586
    
     (mm: show node to memory section relationship with
    symlinks in sysfs) created symlinks from nodes to memory sections, e.g.
    
    /sys/devices/system/node/node1/memory135 -> ../../memory/memory135
    
    If you're examining the memory section though and are wondering what node
    it might belong to, you can find it by grovelling around in sysfs, but
    it's a little cumbersome.
    
    Add a reverse symlink for each memory section that points back to the
    node to which it belongs.
    Signed-off-by: default avatarAlex Chiang <achiang@hp.com>
    Cc: Gary Hade <garyhade@us.ibm.com>
    Cc: Badari Pulavarty <pbadari@us.ibm.com>
    Cc: Ingo Molnar <mingo@elte.hu>
    Acked-by: default avatarDavid Rientjes <rientjes@google.com>
    Cc: Greg KH <greg@kroah.com>
    Cc: Randy Dunlap <randy.dunlap@oracle.com>
    Cc: David Rientjes <rientjes@google.com>
    Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
    Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
    Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
    dee5d0d5
sysfs-devices-memory 3.29 KB
What:		/sys/devices/system/memory
Date:		June 2008
Contact:	Badari Pulavarty <pbadari@us.ibm.com>
Description:
		The /sys/devices/system/memory contains a snapshot of the
		internal state of the kernel memory blocks. Files could be
		added or removed dynamically to represent hot-add/remove
		operations.
Users:		hotplug memory add/remove tools
		https://w3.opensource.ibm.com/projects/powerpc-utils/

What:		/sys/devices/system/memory/memoryX/removable
Date:		June 2008
Contact:	Badari Pulavarty <pbadari@us.ibm.com>
Description:
		The file /sys/devices/system/memory/memoryX/removable
		indicates whether this memory block is removable or not.
		This is useful for a user-level agent to determine
		identify removable sections of the memory before attempting
		potentially expensive hot-remove memory operation
Users:		hotplug memory remove tools
		https://w3.opensource.ibm.com/projects/powerpc-utils/

What:		/sys/devices/system/memory/memoryX/phys_device
Date:		September 2008
Contact:	Badari Pulavarty <pbadari@us.ibm.com>
Description:
		The file /sys/devices/system/memory/memoryX/phys_device
		is read-only and is designed to show the name of physical
		memory device.  Implementation is currently incomplete.

What:		/sys/devices/system/memory/memoryX/phys_index
Date:		September 2008
Contact:	Badari Pulavarty <pbadari@us.ibm.com>
Description:
		The file /sys/devices/system/memory/memoryX/phys_index
		is read-only and contains the section ID in hexadecimal
		which is equivalent to decimal X contained in the
		memory section directory name.

What:		/sys/devices/system/memory/memoryX/state
Date:		September 2008
Contact:	Badari Pulavarty <pbadari@us.ibm.com>
Description:
		The file /sys/devices/system/memory/memoryX/state
		is read-write.  When read, it's contents show the
		online/offline state of the memory section.  When written,
		root can toggle the the online/offline state of a removable
		memory section (see removable file description above)
		using the following commands.
		# echo online > /sys/devices/system/memory/memoryX/state
		# echo offline > /sys/devices/system/memory/memoryX/state

		For example, if /sys/devices/system/memory/memory22/removable
		contains a value of 1 and
		/sys/devices/system/memory/memory22/state contains the
		string "online" the following command can be executed by
		by root to offline that section.
		# echo offline > /sys/devices/system/memory/memory22/state
Users:		hotplug memory remove tools
		https://w3.opensource.ibm.com/projects/powerpc-utils/


What:		/sys/devices/system/memoryX/nodeY
Date:		October 2009
Contact:	Linux Memory Management list <linux-mm@kvack.org>
Description:
		When CONFIG_NUMA is enabled, a symbolic link that
		points to the corresponding NUMA node directory.

		For example, the following symbolic link is created for
		memory section 9 on node0:
		/sys/devices/system/memory/memory9/node0 -> ../../node/node0


What:		/sys/devices/system/node/nodeX/memoryY
Date:		September 2008
Contact:	Gary Hade <garyhade@us.ibm.com>
Description:
		When CONFIG_NUMA is enabled
		/sys/devices/system/node/nodeX/memoryY is a symbolic link that
		points to the corresponding /sys/devices/system/memory/memoryY
		memory section directory.  For example, the following symbolic
		link is created for memory section 9 on node0.
		/sys/devices/system/node/node0/memory9 -> ../../memory/memory9