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; it is a legacy interface only ever used on s390x 30 to expose the covered storage increment. 31Users: Legacy s390-tools lsmem/chmem 32 33What: /sys/devices/system/memory/memoryX/phys_index 34Date: September 2008 35Contact: Badari Pulavarty <pbadari@us.ibm.com> 36Description: 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. 41 42What: /sys/devices/system/memory/memoryX/state 43Date: September 2008 44Contact: Badari Pulavarty <pbadari@us.ibm.com> 45Description: 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:: 52 53 # echo online > /sys/devices/system/memory/memoryX/state 54 # echo offline > /sys/devices/system/memory/memoryX/state 55 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:: 61 62 # echo offline > /sys/devices/system/memory/memory22/state 63 64Users: hotplug memory remove tools 65 http://www.ibm.com/developerworks/wikis/display/LinuxP/powerpc-utils 66 67 68What: /sys/devices/system/memory/memoryX/valid_zones 69Date: July 2014 70Contact: Zhang Zhen <zhenzhang.zhang@huawei.com> 71Description: 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. 75 76What: /sys/devices/system/memoryX/nodeY 77Date: October 2009 78Contact: Linux Memory Management list <linux-mm@kvack.org> 79Description: 80 When CONFIG_NUMA is enabled, a symbolic link that 81 points to the corresponding NUMA node directory. 82 83 For example, the following symbolic link is created for 84 memory section 9 on node0: 85 86 /sys/devices/system/memory/memory9/node0 -> ../../node/node0 87 88 89What: /sys/devices/system/node/nodeX/memoryY 90Date: September 2008 91Contact: Gary Hade <garyhade@us.ibm.com> 92Description: 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. 98 99 /sys/devices/system/node/node0/memory9 -> ../../memory/memory9 100