| Badari Pulavarty | 5c755e9 | 2008-07-23 21:28:19 -0700 | [diff] [blame] | 1 | What: /sys/devices/system/memory |
| 2 | Date: June 2008 |
| 3 | Contact: Badari Pulavarty <pbadari@us.ibm.com> |
| 4 | Description: |
| 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. |
| Badari Pulavarty | 5c755e9 | 2008-07-23 21:28:19 -0700 | [diff] [blame] | 9 | Users: hotplug memory add/remove tools |
| 10 | https://w3.opensource.ibm.com/projects/powerpc-utils/ |
| 11 | |
| 12 | What: /sys/devices/system/memory/memoryX/removable |
| 13 | Date: June 2008 |
| 14 | Contact: Badari Pulavarty <pbadari@us.ibm.com> |
| 15 | Description: |
| 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 |
| Badari Pulavarty | 5c755e9 | 2008-07-23 21:28:19 -0700 | [diff] [blame] | 21 | Users: hotplug memory remove tools |
| 22 | https://w3.opensource.ibm.com/projects/powerpc-utils/ |
| Gary Hade | c04fc58 | 2009-01-06 14:39:14 -0800 | [diff] [blame] | 23 | |
| 24 | What: /sys/devices/system/memory/memoryX/phys_device |
| 25 | Date: September 2008 |
| 26 | Contact: Badari Pulavarty <pbadari@us.ibm.com> |
| 27 | Description: |
| 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 | |
| 32 | What: /sys/devices/system/memory/memoryX/phys_index |
| 33 | Date: September 2008 |
| 34 | Contact: Badari Pulavarty <pbadari@us.ibm.com> |
| 35 | Description: |
| 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 | |
| 41 | What: /sys/devices/system/memory/memoryX/state |
| 42 | Date: September 2008 |
| 43 | Contact: Badari Pulavarty <pbadari@us.ibm.com> |
| 44 | Description: |
| 45 | The file /sys/devices/system/memory/memoryX/state |
| 46 | is read-write. When read, it's 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 |
| 60 | Users: hotplug memory remove tools |
| 61 | https://w3.opensource.ibm.com/projects/powerpc-utils/ |
| 62 | |
| 63 | What: /sys/devices/system/node/nodeX/memoryY |
| 64 | Date: September 2008 |
| 65 | Contact: Gary Hade <garyhade@us.ibm.com> |
| 66 | Description: |
| 67 | When CONFIG_NUMA is enabled |
| 68 | /sys/devices/system/node/nodeX/memoryY is a symbolic link that |
| 69 | points to the corresponding /sys/devices/system/memory/memoryY |
| 70 | memory section directory. For example, the following symbolic |
| 71 | link is created for memory section 9 on node0. |
| 72 | /sys/devices/system/node/node0/memory9 -> ../../memory/memory9 |
| 73 | |