Documentation: ABI: /sys/devices/system/node/

Describe NUMA node sysfs files/attributes.

Note that for the specific dates and contacts I couldn't find,
I left it as default for Oct 2002 and linux-mm.
Signed-off-by: Davidlohr Bueso <davidlohr.bueso@hp.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Documentation/ABI/stable/sysfs-devices-node

+What:		/sys/devices/system/node/possible
+Date:		October 2002
+Contact:	Linux Memory Management list <linux-mm@kvack.org>
+Description:
+		Nodes that could be possibly become online at some point.
+
+What:		/sys/devices/system/node/online
+Date:		October 2002
+Contact:	Linux Memory Management list <linux-mm@kvack.org>
+Description:
+		Nodes that are online.
+
+What:		/sys/devices/system/node/has_normal_memory
+Date:		October 2002
+Contact:	Linux Memory Management list <linux-mm@kvack.org>
+Description:
+		Nodes that have regular memory.
+
+What:		/sys/devices/system/node/has_cpu
+Date:		October 2002
+Contact:	Linux Memory Management list <linux-mm@kvack.org>
+Description:
+		Nodes that have one or more CPUs.
+
+What:		/sys/devices/system/node/has_high_memory
+Date:		October 2002
+Contact:	Linux Memory Management list <linux-mm@kvack.org>
+Description:
+		Nodes that have regular or high memory.
+		Depends on CONFIG_HIGHMEM.
+
 What:		/sys/devices/system/node/nodeX
 Date:		October 2002
 Contact:	Linux Memory Management list <linux-mm@kvack.org>
 Description:
 		When CONFIG_NUMA is enabled, this is a directory containing
 		information on node X such as what CPUs are local to the
-		node.
+		node. Each file is detailed next.
+
+What:		/sys/devices/system/node/nodeX/cpumap
+Date:		October 2002
+Contact:	Linux Memory Management list <linux-mm@kvack.org>
+Description:
+		The node's cpumap.
+
+What:		/sys/devices/system/node/nodeX/cpulist
+Date:		October 2002
+Contact:	Linux Memory Management list <linux-mm@kvack.org>
+Description:
+		The CPUs associated to the node.
+
+What:		/sys/devices/system/node/nodeX/meminfo
+Date:		October 2002
+Contact:	Linux Memory Management list <linux-mm@kvack.org>
+Description:
+		Provides information about the node's distribution and memory
+		utilization. Similar to /proc/meminfo, see Documentation/filesystems/proc.txt
+
+What:		/sys/devices/system/node/nodeX/numastat
+Date:		October 2002
+Contact:	Linux Memory Management list <linux-mm@kvack.org>
+Description:
+		The node's hit/miss statistics, in units of pages.
+		See Documentation/numastat.txt
+
+What:		/sys/devices/system/node/nodeX/distance
+Date:		October 2002
+Contact:	Linux Memory Management list <linux-mm@kvack.org>
+Description:
+		Distance between the node and all the other nodes
+		in the system.
+
+What:		/sys/devices/system/node/nodeX/vmstat
+Date:		October 2002
+Contact:	Linux Memory Management list <linux-mm@kvack.org>
+Description:
+		The node's zoned virtual memory statistics.
+		This is a superset of numastat.
+
+What:		/sys/devices/system/node/nodeX/compact
+Date:		February 2010
+Contact:	Mel Gorman <mel@csn.ul.ie>
+Description:
+		When this file is written to, all memory within that node
+		will be compacted. When it completes, memory will be freed
+		into blocks which have as many contiguous pages as possible
+
+What:		/sys/devices/system/node/nodeX/scan_unevictable_pages
+Date:		October 2008
+Contact:	Lee Schermerhorn <lee.schermerhorn@hp.com>
+Description:
+		When set, it triggers scanning the node's unevictable lists
+		and move any pages that have become evictable onto the respective
+		zone's inactive list. See mm/vmscan.c
+
+What:		/sys/devices/system/node/nodeX/hugepages/hugepages-<size>/
+Date:		December 2009
+Contact:	Lee Schermerhorn <lee.schermerhorn@hp.com>
+Description:
+		The node's huge page size control/query attributes.
+		See Documentation/vm/hugetlbpage.txt
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