linux/arch/sh/mm
Gary Hade c04fc586c1 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>
2009-01-06 15:59:00 -08:00
..
Kconfig sh: Make memory hot-add and hot-remove depend on MMU. 2008-09-17 23:13:27 +09:00
Makefile sh: Split out extable.c _32 and _64 variants. 2008-01-28 13:18:44 +09:00
Makefile_32 sh: Convert sh64 /proc/asids to debugfs and generic sh. 2008-12-22 18:44:03 +09:00
Makefile_64 sh: Convert sh64 /proc/asids to debugfs and generic sh. 2008-12-22 18:44:03 +09:00
asids-debugfs.c sh: Fix up the cpu_asid() return value on nommu. 2008-12-22 18:44:03 +09:00
cache-debugfs.c Fix debugfs_create_file's error checking method for arch/sh/mm/ 2008-10-20 10:40:21 +09:00
cache-sh2.c SH2(A) cache update 2008-08-04 16:33:47 +09:00
cache-sh2a.c sh: fix sh2a cache entry_mask 2008-10-31 16:29:20 +09:00
cache-sh3.c sh: Fixup cpu_data references for the non-boot CPUs. 2007-02-13 10:54:45 +09:00
cache-sh4.c sh: uninline flush_icache_all(). 2008-09-08 10:35:06 +09:00
cache-sh5.c sh64: Fixup the nommu build. 2008-05-08 19:51:37 +09:00
cache-sh7705.c sh: Preparation for uncached jumps through PMB. 2008-01-28 13:18:59 +09:00
consistent.c sh: split coherent pages 2008-12-22 18:44:48 +09:00
extable_32.c sh: Split out extable.c _32 and _64 variants. 2008-01-28 13:18:44 +09:00
extable_64.c sh: comment tidying for sh64->sh migration. 2008-01-28 13:18:58 +09:00
fault_32.c sh: Generic kgdb stub support. 2008-12-22 18:44:04 +09:00
fault_64.c sh: migrate to arch/sh/include/ 2008-07-29 08:09:44 +09:00
hugetlbpage.c hugetlb: introduce pud_huge 2008-07-24 10:47:18 -07:00
init.c mm: show node to memory section relationship with symlinks in sysfs 2009-01-06 15:59:00 -08:00
ioremap_32.c sh: P4 ioremap pass-through 2008-12-22 18:43:48 +09:00
ioremap_64.c sh64: export onchip_remap/unmap() too. 2008-05-08 19:51:41 +09:00
mmap.c sh: Move arch_get_unmapped_area() in to arch/sh/mm/mmap.c. 2008-12-22 18:42:49 +09:00
numa.c mm: move bootmem descriptors definition to a single place 2008-07-24 10:47:14 -07:00
pg-nommu.c sh: fixup many sparse errors. 2008-09-08 10:35:04 +09:00
pg-sh4.c sh: Handle fixmap TLB eviction more coherently. 2008-11-10 20:00:45 +09:00
pg-sh7705.c fix sh ptep_get_and_clear breakage 2008-07-28 18:10:35 +09:00
pmb.c Fix debugfs_create_file's error checking method for arch/sh/mm/ 2008-10-20 10:40:21 +09:00
tlb-nommu.c sh: fixup many sparse errors. 2008-09-08 10:35:04 +09:00
tlb-sh3.c sh: Revert lazy dcache writeback changes. 2007-03-05 19:46:47 +09:00
tlb-sh4.c sh: Preparation for uncached jumps through PMB. 2008-01-28 13:18:59 +09:00
tlb-sh5.c sh: Fix up broken kerneldoc comments. 2008-08-04 12:51:06 +09:00
tlbflush_32.c sh: Rename the _32 and _64 TLB flush variants. 2008-01-28 13:18:54 +09:00
tlbflush_64.c sh: replace remaining __FUNCTION__ occurrences 2008-03-06 11:18:22 +09:00