linux-toradex.git/Documentation/memory-hotplug.txt, branch v4.4-rc6

mem-hotplug: fix typo in Documentation/memory-hotplug.txt

2015-03-20T13:41:55+00:00

Fix a trivial typo in Documentation/memory-hotplug.txt.

Signed-off-by: Sheng Yong 
Signed-off-by: Jonathan Corbet

Doc/memory-hotplug.txt: corrections and callback function prototype

2015-02-27T22:05:08+00:00

Documentation/memory-hotplug.txt describes that a callback function can
be added to the notification chain by calling hotplug_memory_notifier().
The function prototype of the callback function is mssing. This missing
information is added by the patch.

The description of the arguments of the callback function is
reworked.

The constants for the event types are corrected.

The possible return values are explained.

Signed-off-by: Heinrich Schuchardt 
Signed-off-by: Jonathan Corbet

memory-hotplug: add sysfs valid_zones attribute

2014-10-10T02:25:52+00:00

Currently memory-hotplug has two limits:

1. If the memory block is in ZONE_NORMAL, you can change it to
   ZONE_MOVABLE, but this memory block must be adjacent to ZONE_MOVABLE.

2. If the memory block is in ZONE_MOVABLE, you can change it to
   ZONE_NORMAL, but this memory block must be adjacent to ZONE_NORMAL.

With this patch, we can easy to know a memory block can be onlined to
which zone, and don't need to know the above two limits.

Updated the related Documentation.

[akpm@linux-foundation.org: use conventional comment layout]
[akpm@linux-foundation.org: fix build with CONFIG_MEMORY_HOTREMOVE=n]
[akpm@linux-foundation.org: remove unused local zone_prev]
Signed-off-by: Zhang Zhen 
Cc: Dave Hansen 
Cc: David Rientjes 
Cc: Toshi Kani 
Cc: Yasuaki Ishimatsu 
Cc: Naoya Horiguchi 
Cc: Wang Nan 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm, hotplug: probe interface is available on several platforms

2014-06-23T23:47:43+00:00

Documentation/memory-hotplug.txt incorrectly states that the memory
driver "probe" interface is only supported on powerpc and is vague about
its application on x86.  Clarify the platforms that make this interface
available if memory hotplug is enabled.

Signed-off-by: David Rientjes 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

memory-hotplug: update documentation to hide information about SECTIONS and remove end_phys_index

2014-06-04T23:53:58+00:00

Seems we all agree that information about SECTION, e.g. section size,
sections per memory block should be kept as kernel internals, and not
exposed to userspace.

This patch updates Documentation/memory-hotplug.txt to refer to memory
blocks instead of memory sections where appropriate and added a
paragraph to explain that memory blocks are made of memory sections.
The documentation update is mostly provided by Nathan.

Also, as end_phys_index in code is actually not the end section id, but
the end memory block id, which should always be the same as phys_index.
So it is removed here.

Signed-off-by: Li Zhong 
Reviewed-by: Zhang Yanfei 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial

2013-09-06T16:36:28+00:00

Pull trivial tree from Jiri Kosina:
 "The usual trivial updates all over the tree -- mostly typo fixes and
  documentation updates"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (52 commits)
  doc: Documentation/cputopology.txt fix typo
  treewide: Convert retrun typos to return
  Fix comment typo for init_cma_reserved_pageblock
  Documentation/trace: Correcting and extending tracepoint documentation
  mm/hotplug: fix a typo in Documentation/memory-hotplug.txt
  power: Documentation: Update s2ram link
  doc: fix a typo in Documentation/00-INDEX
  Documentation/printk-formats.txt: No casts needed for u64/s64
  doc: Fix typo "is is" in Documentations
  treewide: Fix printks with 0x%#
  zram: doc fixes
  Documentation/kmemcheck: update kmemcheck documentation
  doc: documentation/hwspinlock.txt fix typo
  PM / Hibernate: add section for resume options
  doc: filesystems : Fix typo in Documentations/filesystems
  scsi/megaraid fixed several typos in comments
  ppc: init_32: Fix error typo "CONFIG_START_KERNEL"
  treewide: Add __GFP_NOWARN to k.alloc calls with v.alloc fallbacks
  page_isolation: Fix a comment typo in test_pages_isolated()
  doc: fix a typo about irq affinity
  ...

mm/hotplug: fix a typo in Documentation/memory-hotplug.txt

2013-08-27T08:55:23+00:00

Fix a trivial typo in Documentation/memory-hotplug.txt

Signed-off-by: Xishi Qiu 
Signed-off-by: Jiri Kosina

mm/hotplug, x86: Disable ARCH_MEMORY_PROBE by default

2013-07-22T09:13:34+00:00

CONFIG_ARCH_MEMORY_PROBE enables the
/sys/devices/system/memory/probe interface, which allows a given
memory address to be hot-added as follows:

 # echo start_address_of_new_memory > /sys/devices/system/memory/probe

(See Documentation/memory-hotplug.txt for more details.)

This probe interface is required on powerpc. On x86, however,
ACPI notifies a memory hotplug event to the kernel, which
performs its hotplug operation as the result.

Therefore, regular users do not need this interface on x86. This probe
interface is also error-prone and misleading that the kernel blindly
adds a given memory address without checking if the memory is present
on the system; no probing is done despite of its name.

The kernel crashes when a user requests to online a memory block
that is not present on the system. This interface is currently
used for testing as it can fake a hotplug event.

This patch disables CONFIG_ARCH_MEMORY_PROBE by default on x86,
adds its Kconfig menu entry on x86, and clarifies its use in
Documentation/ memory-hotplug.txt.

Signed-off-by: Toshi Kani 
Acked-by: KOSAKI Motohiro 
Cc: linux-mm@kvack.org
Cc: dave@sr71.net
Cc: isimatu.yasuaki@jp.fujitsu.com
Cc: tangchen@cn.fujitsu.com
Cc: vasilis.liaskovitis@profitbricks.com
Link: http://lkml.kernel.org/r/1374256068-26016-1-git-send-email-toshi.kani@hp.com
[ Edited it slightly. ]
Signed-off-by: Ingo Molnar

hotplug: update nodemasks management

2012-12-13T01:38:33+00:00

Update nodemasks management for N_MEMORY.

[lliubbo@gmail.com: fix build]
Signed-off-by: Lai Jiangshan 
Signed-off-by: Wen Congyang 
Cc: Christoph Lameter 
Cc: Hillf Danton 
Cc: Lin Feng 
Cc: David Rientjes 
Signed-off-by: Bob Liu 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm, memory-hotplug: dynamic configure movable memory and portion memory

2012-12-12T01:22:28+00:00

Add online_movable and online_kernel for logic memory hotplug.  This is
the dynamic version of "movablecore" & "kernelcore".

We have the same reason to introduce it as to introduce "movablecore" &
"kernelcore".  It has the same motive as "movablecore" & "kernelcore", but
it is dynamic/running-time:

o We can configure memory as kernelcore or movablecore after boot.

  Userspace workload is increased, we need more hugepage, we can't use
  "online_movable" to add memory and allow the system use more
  THP(transparent-huge-page), vice-verse when kernel workload is increase.

  Also help for virtualization to dynamic configure host/guest's memory,
  to save/(reduce waste) memory.

  Memory capacity on Demand

o When a new node is physically online after boot, we need to use
  "online_movable" or "online_kernel" to configure/portion it as we
  expected when we logic-online it.

  This configuration also helps for physically-memory-migrate.

o all benefit as the same as existed "movablecore" & "kernelcore".

o Preparing for movable-node, which is very important for power-saving,
  hardware partitioning and high-available-system(hardware fault
  management).

(Note, we don't introduce movable-node here.)

Action behavior:
When a memoryblock/memorysection is onlined by "online_movable", the kernel
will not have directly reference to the page of the memoryblock,
thus we can remove that memory any time when needed.

When it is online by "online_kernel", the kernel can use it.
When it is online by "online", the zone type doesn't changed.

Current constraints:
Only the memoryblock which is adjacent to the ZONE_MOVABLE
can be online from ZONE_NORMAL to ZONE_MOVABLE.

[akpm@linux-foundation.org: use min_t, cleanups]
Signed-off-by: Lai Jiangshan 
Signed-off-by: Wen Congyang 
Cc: Yasuaki Ishimatsu 
Cc: Lai Jiangshan 
Cc: Jiang Liu 
Cc: KOSAKI Motohiro 
Cc: Minchan Kim 
Cc: Mel Gorman 
Cc: David Rientjes 
Cc: Yinghai Lu 
Cc: Rusty Russell 
Cc: Greg KH 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds