What: /sys/devices/system/memory Date: June 2008 Contact: Badari Pulavarty <pbadari@us.ibm.com> Description: The /sys/devices/system/memory contains a snapshot of the internal state of the kernel memory blocks. Files could be added or removed dynamically to represent hot-add/remove operations. Users: hotplug memory add/remove tools http://www.ibm.com/developerworks/wikis/display/LinuxP/powerpc-utils What: /sys/devices/system/memory/memoryX/removable Date: June 2008 Contact: Badari Pulavarty <pbadari@us.ibm.com> Description: The file /sys/devices/system/memory/memoryX/removable indicates whether this memory block is removable or not. This is useful for a user-level agent to determine identify removable sections of the memory before attempting potentially expensive hot-remove memory operation Users: hotplug memory remove tools http://www.ibm.com/developerworks/wikis/display/LinuxP/powerpc-utils What: /sys/devices/system/memory/memoryX/phys_device Date: September 2008 Contact: Badari Pulavarty <pbadari@us.ibm.com> Description: The file /sys/devices/system/memory/memoryX/phys_device is read-only and is designed to show the name of physical memory device. Implementation is currently incomplete. What: /sys/devices/system/memory/memoryX/phys_index Date: September 2008 Contact: Badari Pulavarty <pbadari@us.ibm.com> Description: The file /sys/devices/system/memory/memoryX/phys_index is read-only and contains the section ID in hexadecimal which is equivalent to decimal X contained in the memory section directory name. What: /sys/devices/system/memory/memoryX/state Date: September 2008 Contact: Badari Pulavarty <pbadari@us.ibm.com> Description: The file /sys/devices/system/memory/memoryX/state is read-write. When read, its contents show the online/offline state of the memory section. When written, root can toggle the the online/offline state of a removable memory section (see removable file description above) using the following commands. # echo online > /sys/devices/system/memory/memoryX/state # echo offline > /sys/devices/system/memory/memoryX/state For example, if /sys/devices/system/memory/memory22/removable contains a value of 1 and /sys/devices/system/memory/memory22/state contains the string "online" the following command can be executed by by root to offline that section. # echo offline > /sys/devices/system/memory/memory22/state Users: hotplug memory remove tools http://www.ibm.com/developerworks/wikis/display/LinuxP/powerpc-utils What: /sys/devices/system/memoryX/nodeY Date: October 2009 Contact: Linux Memory Management list <linux-mm@kvack.org> Description: When CONFIG_NUMA is enabled, a symbolic link that points to the corresponding NUMA node directory. For example, the following symbolic link is created for memory section 9 on node0: /sys/devices/system/memory/memory9/node0 -> ../../node/node0 What: /sys/devices/system/node/nodeX/memoryY Date: September 2008 Contact: Gary Hade <garyhade@us.ibm.com> Description: When CONFIG_NUMA is enabled /sys/devices/system/node/nodeX/memoryY is a symbolic link that points to the corresponding /sys/devices/system/memory/memoryY memory section directory. For example, the following symbolic link is created for memory section 9 on node0. /sys/devices/system/node/node0/memory9 -> ../../memory/memory9