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author | Gary Hade <garyhade@us.ibm.com> | 2009-01-07 01:39:14 +0300 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2009-01-07 02:59:00 +0300 |
commit | c04fc586c1a480ba198f03ae7b6cbd7b57380b91 (patch) | |
tree | 9d6544a3b62cc01dbcbb1e315b84378b45ba86d2 /mm/memory_hotplug.c | |
parent | ee53a891f47444c53318b98dac947ede963db400 (diff) | |
download | linux-c04fc586c1a480ba198f03ae7b6cbd7b57380b91.tar.xz |
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')
-rw-r--r-- | mm/memory_hotplug.c | 11 |
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)); } #ifdef CONFIG_SPARSEMEM_VMEMMAP @@ -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 |