| 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 |
| https://w3.opensource.ibm.com/projects/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 |
| https://w3.opensource.ibm.com/projects/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, it's 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 |
| https://w3.opensource.ibm.com/projects/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 |