<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-toradex.git/include/linux/memory.h, branch Colibri_T30_LinuxImageV2.1Beta2_20140206</title>
<subtitle>Linux kernel for Apalis and Colibri modules</subtitle>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/'/>
<entry>
<title>mm: Move definition of MIN_MEMORY_BLOCK_SIZE to a header</title>
<updated>2011-07-12T01:08:01+00:00</updated>
<author>
<name>Benjamin Herrenschmidt</name>
<email>benh@kernel.crashing.org</email>
</author>
<published>2011-06-14T00:57:50+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=a63fdc5156f2ef5690b6cf03d72b0c4917efbba7'/>
<id>a63fdc5156f2ef5690b6cf03d72b0c4917efbba7</id>
<content type='text'>
The macro MIN_MEMORY_BLOCK_SIZE is currently defined twice in two .c
files, and I need it in a third one to fix a powerpc bug, so let's
first move it into a header

Signed-off-by: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
Acked-by: Ingo Molnar &lt;mingo@elte.hu&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The macro MIN_MEMORY_BLOCK_SIZE is currently defined twice in two .c
files, and I need it in a third one to fix a powerpc bug, so let's
first move it into a header

Signed-off-by: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
Acked-by: Ingo Molnar &lt;mingo@elte.hu&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>memory hotplug: Update phys_index to [start|end]_section_nr</title>
<updated>2011-02-04T00:08:57+00:00</updated>
<author>
<name>Nathan Fontenot</name>
<email>nfont@austin.ibm.com</email>
</author>
<published>2011-01-20T16:44:29+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=d33601644cd3b09afb2edd9474517edc441c8fad'/>
<id>d33601644cd3b09afb2edd9474517edc441c8fad</id>
<content type='text'>
Update the 'phys_index' property of a the memory_block struct to be
called start_section_nr, and add a end_section_nr property.  The
data tracked here is the same but the updated naming is more in line
with what is stored here, namely the first and last section number
that the memory block spans.

The names presented to userspace remain the same, phys_index for
start_section_nr and end_phys_index for end_section_nr, to avoid breaking
anything in userspace.

This also updates the node sysfs code to be aware of the new capability for
a memory block to contain multiple memory sections and be aware of the memory
block structure name changes (start_section_nr).  This requires an additional
parameter to unregister_mem_sect_under_nodes so that we know which memory
section of the memory block to unregister.

Signed-off-by: Nathan Fontenot &lt;nfont@austin.ibm.com&gt;
Reviewed-by: Robin Holt &lt;holt@sgi.com&gt;
Reviewed-by: KAMEZAWA Hiroyuki &lt;kamezawa.hiroyu@jp.fujitsu.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@suse.de&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Update the 'phys_index' property of a the memory_block struct to be
called start_section_nr, and add a end_section_nr property.  The
data tracked here is the same but the updated naming is more in line
with what is stored here, namely the first and last section number
that the memory block spans.

The names presented to userspace remain the same, phys_index for
start_section_nr and end_phys_index for end_section_nr, to avoid breaking
anything in userspace.

This also updates the node sysfs code to be aware of the new capability for
a memory block to contain multiple memory sections and be aware of the memory
block structure name changes (start_section_nr).  This requires an additional
parameter to unregister_mem_sect_under_nodes so that we know which memory
section of the memory block to unregister.

Signed-off-by: Nathan Fontenot &lt;nfont@austin.ibm.com&gt;
Reviewed-by: Robin Holt &lt;holt@sgi.com&gt;
Reviewed-by: KAMEZAWA Hiroyuki &lt;kamezawa.hiroyu@jp.fujitsu.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@suse.de&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Driver core: Add section count to memory_block struct</title>
<updated>2010-10-22T17:16:44+00:00</updated>
<author>
<name>Nathan Fontenot</name>
<email>nfont@austin.ibm.com</email>
</author>
<published>2010-10-19T17:46:19+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=07681215975e05a1454b0afdeef07deb0db626ee'/>
<id>07681215975e05a1454b0afdeef07deb0db626ee</id>
<content type='text'>
Add a section count property to the memory_block struct to track the number
of memory sections that have been added/removed from a memory block. This
allows us to know when the last memory section of a memory block has been
removed so we can remove the memory block.

Signed-off-by: Nathan Fontenot &lt;nfont@austin.ibm.com&gt;
Reviewed-by: Robin Holt &lt;holt@sgi.com&gt;
Reviewed-by: KAMEZAWA Hiroyuki &lt;kamezawa.hiroyu@jp.fujitsu.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@suse.de&gt;


</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Add a section count property to the memory_block struct to track the number
of memory sections that have been added/removed from a memory block. This
allows us to know when the last memory section of a memory block has been
removed so we can remove the memory block.

Signed-off-by: Nathan Fontenot &lt;nfont@austin.ibm.com&gt;
Reviewed-by: Robin Holt &lt;holt@sgi.com&gt;
Reviewed-by: KAMEZAWA Hiroyuki &lt;kamezawa.hiroyu@jp.fujitsu.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@suse.de&gt;


</pre>
</div>
</content>
</entry>
<entry>
<title>driver core: Introduce find_memory_block_hinted which utilizes kset_find_obj_hinted.</title>
<updated>2010-10-22T17:16:44+00:00</updated>
<author>
<name>Robin Holt</name>
<email>holt@sgi.com</email>
</author>
<published>2010-09-29T19:00:55+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=98383031ed77c6eb49ab612166fef9c0efe1604a'/>
<id>98383031ed77c6eb49ab612166fef9c0efe1604a</id>
<content type='text'>
Introduce a find_memory_block_hinted() which utilizes the
recently added kset_find_obj_hinted().

Signed-off-by: Robin Holt &lt;holt@sgi.com&gt;
To: Dave Hansen &lt;haveblue@us.ibm.com&gt;
To: Matt Tolentino &lt;matthew.e.tolentino@intel.com&gt;
Reviewed-by: KAMEZAWA Hiroyuki &lt;kamezawa.hiroyu@jp.fujitsu.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@suse.de&gt;


</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Introduce a find_memory_block_hinted() which utilizes the
recently added kset_find_obj_hinted().

Signed-off-by: Robin Holt &lt;holt@sgi.com&gt;
To: Dave Hansen &lt;haveblue@us.ibm.com&gt;
To: Matt Tolentino &lt;matthew.e.tolentino@intel.com&gt;
Reviewed-by: KAMEZAWA Hiroyuki &lt;kamezawa.hiroyu@jp.fujitsu.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@suse.de&gt;


</pre>
</div>
</content>
</entry>
<entry>
<title>memory hotplug: allow setting of phys_device</title>
<updated>2010-03-18T01:43:47+00:00</updated>
<author>
<name>Heiko Carstens</name>
<email>heiko.carstens@de.ibm.com</email>
</author>
<published>2010-03-15T04:35:03+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=bc32df00894f0e1dbf583cc3dab210d2969b078a'/>
<id>bc32df00894f0e1dbf583cc3dab210d2969b078a</id>
<content type='text'>
/sys/devices/system/memory/memoryX/phys_device is supposed to contain the
number of the physical device that the corresponding piece of memory
belongs to.

In case a physical device should be replaced or taken offline for whatever
reason it is necessary to set all corresponding memory pieces offline.
The current implementation always sets phys_device to '0' and there is no
way or hook to change that.  Seems like there was a plan to implement that
but it wasn't finished for whatever reason.

So add a weak function which architectures can override to actually set
the phys_device from within add_memory_block().

Signed-off-by: Heiko Carstens &lt;heiko.carstens@de.ibm.com&gt;
Cc: Dave Hansen &lt;haveblue@us.ibm.com&gt;
Cc: Gerald Schaefer &lt;gerald.schaefer@de.ibm.com&gt;
Cc: KAMEZAWA Hiroyuki &lt;kamezawa.hiroyu@jp.fujitsu.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
/sys/devices/system/memory/memoryX/phys_device is supposed to contain the
number of the physical device that the corresponding piece of memory
belongs to.

In case a physical device should be replaced or taken offline for whatever
reason it is necessary to set all corresponding memory pieces offline.
The current implementation always sets phys_device to '0' and there is no
way or hook to change that.  Seems like there was a plan to implement that
but it wasn't finished for whatever reason.

So add a weak function which architectures can override to actually set
the phys_device from within add_memory_block().

Signed-off-by: Heiko Carstens &lt;heiko.carstens@de.ibm.com&gt;
Cc: Dave Hansen &lt;haveblue@us.ibm.com&gt;
Cc: Gerald Schaefer &lt;gerald.schaefer@de.ibm.com&gt;
Cc: KAMEZAWA Hiroyuki &lt;kamezawa.hiroyu@jp.fujitsu.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>mm: Add notifier in pageblock isolation for balloon drivers</title>
<updated>2009-12-18T03:53:36+00:00</updated>
<author>
<name>Robert Jennings</name>
<email>rcj@linux.vnet.ibm.com</email>
</author>
<published>2009-12-17T14:44:38+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=925cc71e512a29e2594bcc17dc58d0a0e9c4d524'/>
<id>925cc71e512a29e2594bcc17dc58d0a0e9c4d524</id>
<content type='text'>
Memory balloon drivers can allocate a large amount of memory which is not
movable but could be freed to accomodate memory hotplug remove.

Prior to calling the memory hotplug notifier chain the memory in the
pageblock is isolated.  Currently, if the migrate type is not
MIGRATE_MOVABLE the isolation will not proceed, causing the memory removal
for that page range to fail.

Rather than failing pageblock isolation if the migrateteype is not
MIGRATE_MOVABLE, this patch checks if all of the pages in the pageblock,
and not on the LRU, are owned by a registered balloon driver (or other
entity) using a notifier chain.  If all of the non-movable pages are owned
by a balloon, they can be freed later through the memory notifier chain
and the range can still be isolated in set_migratetype_isolate().

Signed-off-by: Robert Jennings &lt;rcj@linux.vnet.ibm.com&gt;
Cc: Mel Gorman &lt;mel@csn.ul.ie&gt;
Cc: Ingo Molnar &lt;mingo@elte.hu&gt;
Cc: Brian King &lt;brking@linux.vnet.ibm.com&gt;
Cc: Paul Mackerras &lt;paulus@samba.org&gt;
Cc: Martin Schwidefsky &lt;schwidefsky@de.ibm.com&gt;
Cc: Gerald Schaefer &lt;geralds@linux.vnet.ibm.com&gt;
Cc: KAMEZAWA Hiroyuki &lt;kamezawa.hiroyu@jp.fujitsu.com&gt;
Cc: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Memory balloon drivers can allocate a large amount of memory which is not
movable but could be freed to accomodate memory hotplug remove.

Prior to calling the memory hotplug notifier chain the memory in the
pageblock is isolated.  Currently, if the migrate type is not
MIGRATE_MOVABLE the isolation will not proceed, causing the memory removal
for that page range to fail.

Rather than failing pageblock isolation if the migrateteype is not
MIGRATE_MOVABLE, this patch checks if all of the pages in the pageblock,
and not on the LRU, are owned by a registered balloon driver (or other
entity) using a notifier chain.  If all of the non-movable pages are owned
by a balloon, they can be freed later through the memory notifier chain
and the range can still be isolated in set_migratetype_isolate().

Signed-off-by: Robert Jennings &lt;rcj@linux.vnet.ibm.com&gt;
Cc: Mel Gorman &lt;mel@csn.ul.ie&gt;
Cc: Ingo Molnar &lt;mingo@elte.hu&gt;
Cc: Brian King &lt;brking@linux.vnet.ibm.com&gt;
Cc: Paul Mackerras &lt;paulus@samba.org&gt;
Cc: Martin Schwidefsky &lt;schwidefsky@de.ibm.com&gt;
Cc: Gerald Schaefer &lt;geralds@linux.vnet.ibm.com&gt;
Cc: KAMEZAWA Hiroyuki &lt;kamezawa.hiroyu@jp.fujitsu.com&gt;
Cc: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge branch 'tracing-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip</title>
<updated>2009-04-05T18:04:19+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2009-04-05T18:04:19+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=714f83d5d9f7c785f622259dad1f4fad12d64664'/>
<id>714f83d5d9f7c785f622259dad1f4fad12d64664</id>
<content type='text'>
* 'tracing-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (413 commits)
  tracing, net: fix net tree and tracing tree merge interaction
  tracing, powerpc: fix powerpc tree and tracing tree interaction
  ring-buffer: do not remove reader page from list on ring buffer free
  function-graph: allow unregistering twice
  trace: make argument 'mem' of trace_seq_putmem() const
  tracing: add missing 'extern' keywords to trace_output.h
  tracing: provide trace_seq_reserve()
  blktrace: print out BLK_TN_MESSAGE properly
  blktrace: extract duplidate code
  blktrace: fix memory leak when freeing struct blk_io_trace
  blktrace: fix blk_probes_ref chaos
  blktrace: make classic output more classic
  blktrace: fix off-by-one bug
  blktrace: fix the original blktrace
  blktrace: fix a race when creating blk_tree_root in debugfs
  blktrace: fix timestamp in binary output
  tracing, Text Edit Lock: cleanup
  tracing: filter fix for TRACE_EVENT_FORMAT events
  ftrace: Using FTRACE_WARN_ON() to check "freed record" in ftrace_release()
  x86: kretprobe-booster interrupt emulation code fix
  ...

Fix up trivial conflicts in
 arch/parisc/include/asm/ftrace.h
 include/linux/memory.h
 kernel/extable.c
 kernel/module.c
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
* 'tracing-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (413 commits)
  tracing, net: fix net tree and tracing tree merge interaction
  tracing, powerpc: fix powerpc tree and tracing tree interaction
  ring-buffer: do not remove reader page from list on ring buffer free
  function-graph: allow unregistering twice
  trace: make argument 'mem' of trace_seq_putmem() const
  tracing: add missing 'extern' keywords to trace_output.h
  tracing: provide trace_seq_reserve()
  blktrace: print out BLK_TN_MESSAGE properly
  blktrace: extract duplidate code
  blktrace: fix memory leak when freeing struct blk_io_trace
  blktrace: fix blk_probes_ref chaos
  blktrace: make classic output more classic
  blktrace: fix off-by-one bug
  blktrace: fix the original blktrace
  blktrace: fix a race when creating blk_tree_root in debugfs
  blktrace: fix timestamp in binary output
  tracing, Text Edit Lock: cleanup
  tracing: filter fix for TRACE_EVENT_FORMAT events
  ftrace: Using FTRACE_WARN_ON() to check "freed record" in ftrace_release()
  x86: kretprobe-booster interrupt emulation code fix
  ...

Fix up trivial conflicts in
 arch/parisc/include/asm/ftrace.h
 include/linux/memory.h
 kernel/extable.c
 kernel/module.c
</pre>
</div>
</content>
</entry>
<entry>
<title>memory_accessor: new interface for reading/writing persistent memory</title>
<updated>2009-04-03T02:04:50+00:00</updated>
<author>
<name>Kevin Hilman</name>
<email>khilman@deeprootsystems.com</email>
</author>
<published>2009-04-02T23:56:56+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=06c421ee0d5af95c8c6749ca0ba620cd5010707f'/>
<id>06c421ee0d5af95c8c6749ca0ba620cd5010707f</id>
<content type='text'>
Add an interface by which other kernel code can read/write persistent
memory such as I2C or SPI EEPROMs, or devices which provide NVRAM.  Use
cases include storage of board-specific configuration data like Ethernet
addresses and sensor calibrations.

Original idea, review and improvement suggestions by David Brownell.

Acked-by: David Brownell &lt;dbrownell@users.sourceforge.net&gt;
Signed-off-by: Kevin Hilman &lt;khilman@deeprootsystems.com&gt;
Cc: Jean Delvare &lt;khali@linux-fr.org&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Add an interface by which other kernel code can read/write persistent
memory such as I2C or SPI EEPROMs, or devices which provide NVRAM.  Use
cases include storage of board-specific configuration data like Ethernet
addresses and sensor calibrations.

Original idea, review and improvement suggestions by David Brownell.

Acked-by: David Brownell &lt;dbrownell@users.sourceforge.net&gt;
Signed-off-by: Kevin Hilman &lt;khilman@deeprootsystems.com&gt;
Cc: Jean Delvare &lt;khali@linux-fr.org&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>tracing, Text Edit Lock - Architecture Independent Code</title>
<updated>2009-03-06T15:48:59+00:00</updated>
<author>
<name>Mathieu Desnoyers</name>
<email>mathieu.desnoyers@polymtl.ca</email>
</author>
<published>2009-03-06T15:35:52+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=0e39ac444636ff5be39b26f1cb56d79594654dda'/>
<id>0e39ac444636ff5be39b26f1cb56d79594654dda</id>
<content type='text'>
This is an architecture independant synchronization around kernel text
modifications through use of a global mutex.

A mutex has been chosen so that kprobes, the main user of this, can sleep
during memory allocation between the memory read of the instructions it
must replace and the memory write of the breakpoint.

Other user of this interface: immediate values.

Paravirt and alternatives are always done when SMP is inactive, so there
is no need to use locks.

Signed-off-by: Mathieu Desnoyers &lt;mathieu.desnoyers@polymtl.ca&gt;
LKML-Reference: &lt;49B142D8.7020601@redhat.com&gt;
Signed-off-by: Ingo Molnar &lt;mingo@elte.hu&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
This is an architecture independant synchronization around kernel text
modifications through use of a global mutex.

A mutex has been chosen so that kprobes, the main user of this, can sleep
during memory allocation between the memory read of the instructions it
must replace and the memory write of the breakpoint.

Other user of this interface: immediate values.

Paravirt and alternatives are always done when SMP is inactive, so there
is no need to use locks.

Signed-off-by: Mathieu Desnoyers &lt;mathieu.desnoyers@polymtl.ca&gt;
LKML-Reference: &lt;49B142D8.7020601@redhat.com&gt;
Signed-off-by: Ingo Molnar &lt;mingo@elte.hu&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>mm: show node to memory section relationship with symlinks in sysfs</title>
<updated>2009-01-06T23:59:00+00:00</updated>
<author>
<name>Gary Hade</name>
<email>garyhade@us.ibm.com</email>
</author>
<published>2009-01-06T22:39:14+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=c04fc586c1a480ba198f03ae7b6cbd7b57380b91'/>
<id>c04fc586c1a480ba198f03ae7b6cbd7b57380b91</id>
<content type='text'>
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 -&gt; ../../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 &lt;garyhade@us.ibm.com&gt;
Signed-off-by: Badari Pulavarty &lt;pbadari@us.ibm.com&gt;
Acked-by: Ingo Molnar &lt;mingo@elte.hu&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
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<pre>
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 -&gt; ../../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 &lt;garyhade@us.ibm.com&gt;
Signed-off-by: Badari Pulavarty &lt;pbadari@us.ibm.com&gt;
Acked-by: Ingo Molnar &lt;mingo@elte.hu&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</pre>
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