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Badari Pulavarty5c755e92008-07-23 21:28:19 -07001What: /sys/devices/system/memory
2Date: June 2008
3Contact: Badari Pulavarty <pbadari@us.ibm.com>
4Description:
5 The /sys/devices/system/memory contains a snapshot of the
6 internal state of the kernel memory blocks. Files could be
7 added or removed dynamically to represent hot-add/remove
8 operations.
Badari Pulavarty5c755e92008-07-23 21:28:19 -07009Users: hotplug memory add/remove tools
Justin P. Mattock0ea6e612010-07-23 20:51:24 -070010 http://www.ibm.com/developerworks/wikis/display/LinuxP/powerpc-utils
Badari Pulavarty5c755e92008-07-23 21:28:19 -070011
12What: /sys/devices/system/memory/memoryX/removable
13Date: June 2008
14Contact: Badari Pulavarty <pbadari@us.ibm.com>
15Description:
16 The file /sys/devices/system/memory/memoryX/removable
17 indicates whether this memory block is removable or not.
18 This is useful for a user-level agent to determine
19 identify removable sections of the memory before attempting
20 potentially expensive hot-remove memory operation
Badari Pulavarty5c755e92008-07-23 21:28:19 -070021Users: hotplug memory remove tools
Justin P. Mattock0ea6e612010-07-23 20:51:24 -070022 http://www.ibm.com/developerworks/wikis/display/LinuxP/powerpc-utils
Gary Hadec04fc582009-01-06 14:39:14 -080023
24What: /sys/devices/system/memory/memoryX/phys_device
25Date: September 2008
26Contact: Badari Pulavarty <pbadari@us.ibm.com>
27Description:
28 The file /sys/devices/system/memory/memoryX/phys_device
29 is read-only and is designed to show the name of physical
30 memory device. Implementation is currently incomplete.
31
32What: /sys/devices/system/memory/memoryX/phys_index
33Date: September 2008
34Contact: Badari Pulavarty <pbadari@us.ibm.com>
35Description:
36 The file /sys/devices/system/memory/memoryX/phys_index
37 is read-only and contains the section ID in hexadecimal
38 which is equivalent to decimal X contained in the
39 memory section directory name.
40
41What: /sys/devices/system/memory/memoryX/state
42Date: September 2008
43Contact: Badari Pulavarty <pbadari@us.ibm.com>
44Description:
45 The file /sys/devices/system/memory/memoryX/state
Francis Galieguea33f3222010-04-23 00:08:02 +020046 is read-write. When read, its contents show the
Gary Hadec04fc582009-01-06 14:39:14 -080047 online/offline state of the memory section. When written,
48 root can toggle the the online/offline state of a removable
49 memory section (see removable file description above)
50 using the following commands.
51 # echo online > /sys/devices/system/memory/memoryX/state
52 # echo offline > /sys/devices/system/memory/memoryX/state
53
54 For example, if /sys/devices/system/memory/memory22/removable
55 contains a value of 1 and
56 /sys/devices/system/memory/memory22/state contains the
57 string "online" the following command can be executed by
58 by root to offline that section.
59 # echo offline > /sys/devices/system/memory/memory22/state
60Users: hotplug memory remove tools
Justin P. Mattock0ea6e612010-07-23 20:51:24 -070061 http://www.ibm.com/developerworks/wikis/display/LinuxP/powerpc-utils
Gary Hadec04fc582009-01-06 14:39:14 -080062
Alex Chiangdee5d0d2009-12-14 17:59:05 -080063
64What: /sys/devices/system/memoryX/nodeY
65Date: October 2009
66Contact: Linux Memory Management list <linux-mm@kvack.org>
67Description:
68 When CONFIG_NUMA is enabled, a symbolic link that
69 points to the corresponding NUMA node directory.
70
71 For example, the following symbolic link is created for
72 memory section 9 on node0:
73 /sys/devices/system/memory/memory9/node0 -> ../../node/node0
74
75
Gary Hadec04fc582009-01-06 14:39:14 -080076What: /sys/devices/system/node/nodeX/memoryY
77Date: September 2008
78Contact: Gary Hade <garyhade@us.ibm.com>
79Description:
80 When CONFIG_NUMA is enabled
81 /sys/devices/system/node/nodeX/memoryY is a symbolic link that
82 points to the corresponding /sys/devices/system/memory/memoryY
83 memory section directory. For example, the following symbolic
84 link is created for memory section 9 on node0.
85 /sys/devices/system/node/node0/memory9 -> ../../memory/memory9