15c755e9fSBadari PulavartyWhat: /sys/devices/system/memory 25c755e9fSBadari PulavartyDate: June 2008 35c755e9fSBadari PulavartyContact: Badari Pulavarty <pbadari@us.ibm.com> 45c755e9fSBadari PulavartyDescription: 55c755e9fSBadari Pulavarty The /sys/devices/system/memory contains a snapshot of the 65c755e9fSBadari Pulavarty internal state of the kernel memory blocks. Files could be 75c755e9fSBadari Pulavarty added or removed dynamically to represent hot-add/remove 85c755e9fSBadari Pulavarty operations. 95c755e9fSBadari PulavartyUsers: hotplug memory add/remove tools 105c755e9fSBadari Pulavarty https://w3.opensource.ibm.com/projects/powerpc-utils/ 115c755e9fSBadari Pulavarty 125c755e9fSBadari PulavartyWhat: /sys/devices/system/memory/memoryX/removable 135c755e9fSBadari PulavartyDate: June 2008 145c755e9fSBadari PulavartyContact: Badari Pulavarty <pbadari@us.ibm.com> 155c755e9fSBadari PulavartyDescription: 165c755e9fSBadari Pulavarty The file /sys/devices/system/memory/memoryX/removable 175c755e9fSBadari Pulavarty indicates whether this memory block is removable or not. 185c755e9fSBadari Pulavarty This is useful for a user-level agent to determine 195c755e9fSBadari Pulavarty identify removable sections of the memory before attempting 205c755e9fSBadari Pulavarty potentially expensive hot-remove memory operation 215c755e9fSBadari PulavartyUsers: hotplug memory remove tools 225c755e9fSBadari Pulavarty https://w3.opensource.ibm.com/projects/powerpc-utils/ 23*c04fc586SGary Hade 24*c04fc586SGary HadeWhat: /sys/devices/system/memory/memoryX/phys_device 25*c04fc586SGary HadeDate: September 2008 26*c04fc586SGary HadeContact: Badari Pulavarty <pbadari@us.ibm.com> 27*c04fc586SGary HadeDescription: 28*c04fc586SGary Hade The file /sys/devices/system/memory/memoryX/phys_device 29*c04fc586SGary Hade is read-only and is designed to show the name of physical 30*c04fc586SGary Hade memory device. Implementation is currently incomplete. 31*c04fc586SGary Hade 32*c04fc586SGary HadeWhat: /sys/devices/system/memory/memoryX/phys_index 33*c04fc586SGary HadeDate: September 2008 34*c04fc586SGary HadeContact: Badari Pulavarty <pbadari@us.ibm.com> 35*c04fc586SGary HadeDescription: 36*c04fc586SGary Hade The file /sys/devices/system/memory/memoryX/phys_index 37*c04fc586SGary Hade is read-only and contains the section ID in hexadecimal 38*c04fc586SGary Hade which is equivalent to decimal X contained in the 39*c04fc586SGary Hade memory section directory name. 40*c04fc586SGary Hade 41*c04fc586SGary HadeWhat: /sys/devices/system/memory/memoryX/state 42*c04fc586SGary HadeDate: September 2008 43*c04fc586SGary HadeContact: Badari Pulavarty <pbadari@us.ibm.com> 44*c04fc586SGary HadeDescription: 45*c04fc586SGary Hade The file /sys/devices/system/memory/memoryX/state 46*c04fc586SGary Hade is read-write. When read, it's contents show the 47*c04fc586SGary Hade online/offline state of the memory section. When written, 48*c04fc586SGary Hade root can toggle the the online/offline state of a removable 49*c04fc586SGary Hade memory section (see removable file description above) 50*c04fc586SGary Hade using the following commands. 51*c04fc586SGary Hade # echo online > /sys/devices/system/memory/memoryX/state 52*c04fc586SGary Hade # echo offline > /sys/devices/system/memory/memoryX/state 53*c04fc586SGary Hade 54*c04fc586SGary Hade For example, if /sys/devices/system/memory/memory22/removable 55*c04fc586SGary Hade contains a value of 1 and 56*c04fc586SGary Hade /sys/devices/system/memory/memory22/state contains the 57*c04fc586SGary Hade string "online" the following command can be executed by 58*c04fc586SGary Hade by root to offline that section. 59*c04fc586SGary Hade # echo offline > /sys/devices/system/memory/memory22/state 60*c04fc586SGary HadeUsers: hotplug memory remove tools 61*c04fc586SGary Hade https://w3.opensource.ibm.com/projects/powerpc-utils/ 62*c04fc586SGary Hade 63*c04fc586SGary HadeWhat: /sys/devices/system/node/nodeX/memoryY 64*c04fc586SGary HadeDate: September 2008 65*c04fc586SGary HadeContact: Gary Hade <garyhade@us.ibm.com> 66*c04fc586SGary HadeDescription: 67*c04fc586SGary Hade When CONFIG_NUMA is enabled 68*c04fc586SGary Hade /sys/devices/system/node/nodeX/memoryY is a symbolic link that 69*c04fc586SGary Hade points to the corresponding /sys/devices/system/memory/memoryY 70*c04fc586SGary Hade memory section directory. For example, the following symbolic 71*c04fc586SGary Hade link is created for memory section 9 on node0. 72*c04fc586SGary Hade /sys/devices/system/node/node0/memory9 -> ../../memory/memory9 73*c04fc586SGary Hade 74