diff options
| author | Gary Hade <garyhade@us.ibm.com> | 2009-01-06 14:39:14 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2009-01-06 15:59:00 -0800 |
| commit | c04fc586c1a480ba198f03ae7b6cbd7b57380b91 (patch) | |
| tree | 9d6544a3b62cc01dbcbb1e315b84378b45ba86d2 /include/linux/node.h | |
| parent | ee53a891f47444c53318b98dac947ede963db400 (diff) | |
mm: show node to memory section relationship with symlinks in sysfs
Show node to memory section relationship with symlinks in sysfs
Add /sys/devices/system/node/nodeX/memoryY symlinks for all
the memory sections located on nodeX. For example:
/sys/devices/system/node/node1/memory135 -> ../../memory/memory135
indicates that memory section 135 resides on node1.
Also revises documentation to cover this change as well as updating
Documentation/ABI/testing/sysfs-devices-memory to include descriptions
of memory hotremove files 'phys_device', 'phys_index', and 'state'
that were previously not described there.
In addition to it always being a good policy to provide users with
the maximum possible amount of physical location information for
resources that can be hot-added and/or hot-removed, the following
are some (but likely not all) of the user benefits provided by
this change.
Immediate:
- Provides information needed to determine the specific node
on which a defective DIMM is located. This will reduce system
downtime when the node or defective DIMM is swapped out.
- Prevents unintended onlining of a memory section that was
previously offlined due to a defective DIMM. This could happen
during node hot-add when the user or node hot-add assist script
onlines _all_ offlined sections due to user or script inability
to identify the specific memory sections located on the hot-added
node. The consequences of reintroducing the defective memory
could be ugly.
- Provides information needed to vary the amount and distribution
of memory on specific nodes for testing or debugging purposes.
Future:
- Will provide information needed to identify the memory
sections that need to be offlined prior to physical removal
of a specific node.
Symlink creation during boot was tested on 2-node x86_64, 2-node
ppc64, and 2-node ia64 systems. Symlink creation during physical
memory hot-add tested on a 2-node x86_64 system.
Signed-off-by: Gary Hade <garyhade@us.ibm.com>
Signed-off-by: Badari Pulavarty <pbadari@us.ibm.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include/linux/node.h')
| -rw-r--r-- | include/linux/node.h | 13 |
1 files changed, 13 insertions, 0 deletions
diff --git a/include/linux/node.h b/include/linux/node.h index bc001bc225c..681a697b9a8 100644 --- a/include/linux/node.h +++ b/include/linux/node.h @@ -26,6 +26,7 @@ struct node { struct sys_device sysdev; }; +struct memory_block; extern struct node node_devices[]; extern int register_node(struct node *, int, struct node *); @@ -35,6 +36,9 @@ extern int register_one_node(int nid); extern void unregister_one_node(int nid); extern int register_cpu_under_node(unsigned int cpu, unsigned int nid); extern int unregister_cpu_under_node(unsigned int cpu, unsigned int nid); +extern int register_mem_sect_under_node(struct memory_block *mem_blk, + int nid); +extern int unregister_mem_sect_under_nodes(struct memory_block *mem_blk); #else static inline int register_one_node(int nid) { @@ -52,6 +56,15 @@ static inline int unregister_cpu_under_node(unsigned int cpu, unsigned int nid) { return 0; } +static inline int register_mem_sect_under_node(struct memory_block *mem_blk, + int nid) +{ + return 0; +} +static inline int unregister_mem_sect_under_nodes(struct memory_block *mem_blk) +{ + return 0; +} #endif #define to_node(sys_device) container_of(sys_device, struct node, sysdev) |