path: root/mm/memory_hotplug.c
diff options
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 /mm/memory_hotplug.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 'mm/memory_hotplug.c')
1 files changed, 6 insertions, 5 deletions
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index b17371185468..2ba38bc07b47 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -216,7 +216,8 @@ static int __meminit __add_zone(struct zone *zone, unsigned long phys_start_pfn)
return 0;
-static int __meminit __add_section(struct zone *zone, unsigned long phys_start_pfn)
+static int __meminit __add_section(int nid, struct zone *zone,
+ unsigned long phys_start_pfn)
int nr_pages = PAGES_PER_SECTION;
int ret;
@@ -234,7 +235,7 @@ static int __meminit __add_section(struct zone *zone, unsigned long phys_start_p
if (ret < 0)
return ret;
- return register_new_memory(__pfn_to_section(phys_start_pfn));
+ return register_new_memory(nid, __pfn_to_section(phys_start_pfn));
@@ -273,8 +274,8 @@ static int __remove_section(struct zone *zone, struct mem_section *ms)
* call this function after deciding the zone to which to
* add the new pages.
-int __ref __add_pages(struct zone *zone, unsigned long phys_start_pfn,
- unsigned long nr_pages)
+int __ref __add_pages(int nid, struct zone *zone, unsigned long phys_start_pfn,
+ unsigned long nr_pages)
unsigned long i;
int err = 0;
@@ -284,7 +285,7 @@ int __ref __add_pages(struct zone *zone, unsigned long phys_start_pfn,
end_sec = pfn_to_section_nr(phys_start_pfn + nr_pages - 1);
for (i = start_sec; i <= end_sec; i++) {
- err = __add_section(zone, i << PFN_SECTION_SHIFT);
+ err = __add_section(nid, zone, i << PFN_SECTION_SHIFT);
* EEXIST is finally dealt with by ioresource collision

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