1What: /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. 9Users: hotplug memory add/remove tools 10 http://www.ibm.com/developerworks/wikis/display/LinuxP/powerpc-utils 11 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 21Users: hotplug memory remove tools 22 http://www.ibm.com/developerworks/wikis/display/LinuxP/powerpc-utils 23 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 46 is read-write. When read, its contents show the 47 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 61 http://www.ibm.com/developerworks/wikis/display/LinuxP/powerpc-utils 62 63 64What: /sys/devices/system/memory/memoryX/valid_zones 65Date: July 2014 66Contact: Zhang Zhen <zhenzhang.zhang@huawei.com> 67Description: 68 The file /sys/devices/system/memory/memoryX/valid_zones is 69 read-only and is designed to show which zone this memory 70 block can be onlined to. 71 72What: /sys/devices/system/memoryX/nodeY 73Date: October 2009 74Contact: Linux Memory Management list <linux-mm@kvack.org> 75Description: 76 When CONFIG_NUMA is enabled, a symbolic link that 77 points to the corresponding NUMA node directory. 78 79 For example, the following symbolic link is created for 80 memory section 9 on node0: 81 /sys/devices/system/memory/memory9/node0 -> ../../node/node0 82 83 84What: /sys/devices/system/node/nodeX/memoryY 85Date: September 2008 86Contact: Gary Hade <garyhade@us.ibm.com> 87Description: 88 When CONFIG_NUMA is enabled 89 /sys/devices/system/node/nodeX/memoryY is a symbolic link that 90 points to the corresponding /sys/devices/system/memory/memoryY 91 memory section directory. For example, the following symbolic 92 link is created for memory section 9 on node0. 93 /sys/devices/system/node/node0/memory9 -> ../../memory/memory9 94