1 What: /sys/devices/system/memory
3 Contact: Badari Pulavarty <pbadari@us.ibm.com>
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
9 Users: hotplug memory add/remove tools
10 http://www.ibm.com/developerworks/wikis/display/LinuxP/powerpc-utils
12 What: /sys/devices/system/memory/memoryX/removable
14 Contact: Badari Pulavarty <pbadari@us.ibm.com>
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
21 Users: hotplug memory remove tools
22 http://www.ibm.com/developerworks/wikis/display/LinuxP/powerpc-utils
24 What: /sys/devices/system/memory/memoryX/phys_device
26 Contact: Badari Pulavarty <pbadari@us.ibm.com>
28 The file /sys/devices/system/memory/memoryX/phys_device
29 is read-only; it is a legacy interface only ever used on s390x
30 to expose the covered storage increment.
31 Users: Legacy s390-tools lsmem/chmem
33 What: /sys/devices/system/memory/memoryX/phys_index
35 Contact: Badari Pulavarty <pbadari@us.ibm.com>
37 The file /sys/devices/system/memory/memoryX/phys_index
38 is read-only and contains the section ID in hexadecimal
39 which is equivalent to decimal X contained in the
40 memory section directory name.
42 What: /sys/devices/system/memory/memoryX/state
44 Contact: Badari Pulavarty <pbadari@us.ibm.com>
46 The file /sys/devices/system/memory/memoryX/state
47 is read-write. When read, its contents show the
48 online/offline state of the memory section. When written,
49 root can toggle the the online/offline state of a removable
50 memory section (see removable file description above)
51 using the following commands::
53 # echo online > /sys/devices/system/memory/memoryX/state
54 # echo offline > /sys/devices/system/memory/memoryX/state
56 For example, if /sys/devices/system/memory/memory22/removable
57 contains a value of 1 and
58 /sys/devices/system/memory/memory22/state contains the
59 string "online" the following command can be executed by
60 by root to offline that section::
62 # echo offline > /sys/devices/system/memory/memory22/state
64 Users: hotplug memory remove tools
65 http://www.ibm.com/developerworks/wikis/display/LinuxP/powerpc-utils
68 What: /sys/devices/system/memory/memoryX/valid_zones
70 Contact: Zhang Zhen <zhenzhang.zhang@huawei.com>
72 The file /sys/devices/system/memory/memoryX/valid_zones is
73 read-only and is designed to show which zone this memory
74 block can be onlined to.
76 What: /sys/devices/system/memoryX/nodeY
78 Contact: Linux Memory Management list <linux-mm@kvack.org>
80 When CONFIG_NUMA is enabled, a symbolic link that
81 points to the corresponding NUMA node directory.
83 For example, the following symbolic link is created for
84 memory section 9 on node0:
86 /sys/devices/system/memory/memory9/node0 -> ../../node/node0
89 What: /sys/devices/system/node/nodeX/memoryY
91 Contact: Gary Hade <garyhade@us.ibm.com>
93 When CONFIG_NUMA is enabled
94 /sys/devices/system/node/nodeX/memoryY is a symbolic link that
95 points to the corresponding /sys/devices/system/memory/memoryY
96 memory section directory. For example, the following symbolic
97 link is created for memory section 9 on node0.
99 /sys/devices/system/node/node0/memory9 -> ../../memory/memory9