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authorGary Hade <garyhade@us.ibm.com>2009-01-06 14:39:14 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2009-01-06 15:59:00 -0800
commitc04fc586c1a480ba198f03ae7b6cbd7b57380b91 (patch)
tree9d6544a3b62cc01dbcbb1e315b84378b45ba86d2 /drivers/base/memory.c
parentee53a891f47444c53318b98dac947ede963db400 (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 'drivers/base/memory.c')
-rw-r--r--drivers/base/memory.c19
1 files changed, 13 insertions, 6 deletions
diff --git a/drivers/base/memory.c b/drivers/base/memory.c
index 5260e9e0df4..989429cfed8 100644
--- a/drivers/base/memory.c
+++ b/drivers/base/memory.c
@@ -347,8 +347,9 @@ static inline int memory_probe_init(void)
* section belongs to...
*/
-static int add_memory_block(unsigned long node_id, struct mem_section *section,
- unsigned long state, int phys_device)
+static int add_memory_block(int nid, struct mem_section *section,
+ unsigned long state, int phys_device,
+ enum mem_add_context context)
{
struct memory_block *mem = kzalloc(sizeof(*mem), GFP_KERNEL);
int ret = 0;
@@ -370,6 +371,10 @@ static int add_memory_block(unsigned long node_id, struct mem_section *section,
ret = mem_create_simple_file(mem, phys_device);
if (!ret)
ret = mem_create_simple_file(mem, removable);
+ if (!ret) {
+ if (context == HOTPLUG)
+ ret = register_mem_sect_under_node(mem, nid);
+ }
return ret;
}
@@ -382,7 +387,7 @@ static int add_memory_block(unsigned long node_id, struct mem_section *section,
*
* This could be made generic for all sysdev classes.
*/
-static struct memory_block *find_memory_block(struct mem_section *section)
+struct memory_block *find_memory_block(struct mem_section *section)
{
struct kobject *kobj;
struct sys_device *sysdev;
@@ -411,6 +416,7 @@ int remove_memory_block(unsigned long node_id, struct mem_section *section,
struct memory_block *mem;
mem = find_memory_block(section);
+ unregister_mem_sect_under_nodes(mem);
mem_remove_simple_file(mem, phys_index);
mem_remove_simple_file(mem, state);
mem_remove_simple_file(mem, phys_device);
@@ -424,9 +430,9 @@ int remove_memory_block(unsigned long node_id, struct mem_section *section,
* need an interface for the VM to add new memory regions,
* but without onlining it.
*/
-int register_new_memory(struct mem_section *section)
+int register_new_memory(int nid, struct mem_section *section)
{
- return add_memory_block(0, section, MEM_OFFLINE, 0);
+ return add_memory_block(nid, section, MEM_OFFLINE, 0, HOTPLUG);
}
int unregister_memory_section(struct mem_section *section)
@@ -458,7 +464,8 @@ int __init memory_dev_init(void)
for (i = 0; i < NR_MEM_SECTIONS; i++) {
if (!present_section_nr(i))
continue;
- err = add_memory_block(0, __nr_to_section(i), MEM_ONLINE, 0);
+ err = add_memory_block(0, __nr_to_section(i), MEM_ONLINE,
+ 0, BOOT);
if (!ret)
ret = err;
}