linux-stable/drivers/base
Yasuaki Ishimatsu 8a1f780e7f memory_hotplug: make zone_can_shift() return a boolean value
online_{kernel|movable} is used to change the memory zone to
ZONE_{NORMAL|MOVABLE} and online the memory.

To check that memory zone can be changed, zone_can_shift() is used.
Currently the function returns minus integer value, plus integer
value and 0. When the function returns minus or plus integer value,
it means that the memory zone can be changed to ZONE_{NORNAL|MOVABLE}.

But when the function returns 0, there are two meanings.

One of the meanings is that the memory zone does not need to be changed.
For example, when memory is in ZONE_NORMAL and onlined by online_kernel
the memory zone does not need to be changed.

Another meaning is that the memory zone cannot be changed. When memory
is in ZONE_NORMAL and onlined by online_movable, the memory zone may
not be changed to ZONE_MOVALBE due to memory online limitation(see
Documentation/memory-hotplug.txt). In this case, memory must not be
onlined.

The patch changes the return type of zone_can_shift() so that memory
online operation fails when memory zone cannot be changed as follows:

Before applying patch:
   # grep -A 35 "Node 2" /proc/zoneinfo
   Node 2, zone   Normal
   <snip>
      node_scanned  0
           spanned  8388608
           present  7864320
           managed  7864320
   # echo online_movable > memory4097/state
   # grep -A 35 "Node 2" /proc/zoneinfo
   Node 2, zone   Normal
   <snip>
      node_scanned  0
           spanned  8388608
           present  8388608
           managed  8388608

   online_movable operation succeeded. But memory is onlined as
   ZONE_NORMAL, not ZONE_MOVABLE.

After applying patch:
   # grep -A 35 "Node 2" /proc/zoneinfo
   Node 2, zone   Normal
   <snip>
      node_scanned  0
           spanned  8388608
           present  7864320
           managed  7864320
   # echo online_movable > memory4097/state
   bash: echo: write error: Invalid argument
   # grep -A 35 "Node 2" /proc/zoneinfo
   Node 2, zone   Normal
   <snip>
      node_scanned  0
           spanned  8388608
           present  7864320
           managed  7864320

   online_movable operation failed because of failure of changing
   the memory zone from ZONE_NORMAL to ZONE_MOVABLE

Fixes: df429ac039 ("memory-hotplug: more general validation of zone during online")
Link: http://lkml.kernel.org/r/2f9c3837-33d7-b6e5-59c0-6ca4372b2d84@gmail.com
Signed-off-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Reviewed-by: Reza Arbab <arbab@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-01-24 16:26:14 -08:00
..
power PM / domains: Fix 'may be used uninitialized' build warning 2016-12-31 21:52:07 +01:00
regmap regmap: cache: Remove unused 'blksize' variable 2016-11-25 13:01:36 +00:00
test driver core: test_async: fix up typo found by 0-day 2016-11-29 22:06:42 +01:00
attribute_container.c attribute_container: Fix typo 2016-08-31 15:13:56 +02:00
base.h Revert "driver core: Add deferred_probe attribute to devices in sysfs" 2017-01-14 14:09:03 +01:00
bus.c driver core: bus: use to_subsys_private and to_device_private_bus 2016-02-09 17:25:27 -08:00
cacheinfo.c Merge branch 'x86-cache-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2016-12-22 09:25:45 -08:00
class.c driver core: class: add class_groups support 2016-11-29 21:12:12 +01:00
component.c Merge 4.5-rc4 into driver-core-next 2016-02-14 14:29:55 -08:00
container.c
core.c Revert "driver core: Add deferred_probe attribute to devices in sysfs" 2017-01-14 14:09:03 +01:00
cpu.c cpu: clean up register_cpu func 2016-08-31 15:19:55 +02:00
dd.c Revert "driver core: Add deferred_probe attribute to devices in sysfs" 2017-01-14 14:09:03 +01:00
devcoredump.c driver core: devcoredump: convert to use class_groups 2016-11-29 21:12:12 +01:00
devres.c devres: add devm_alloc_percpu() 2016-11-15 22:34:25 -05:00
devtmpfs.c wrappers for ->i_mutex access 2016-01-22 18:04:28 -05:00
dma-coherent.c drivers: dma-coherent: Move spinlock in dma_alloc_from_coherent() 2016-09-28 17:53:16 +02:00
dma-contiguous.c driver core update for 4.4-rc1 2015-11-04 21:50:37 -08:00
dma-mapping.c drivers: base: dma-mapping: Fix typo in dmam_alloc_non_coherent comments 2016-11-30 13:04:53 +01:00
driver.c
firmware.c
firmware_class.c firmware: Correct handling of fw_state_wait() return value 2016-12-08 21:05:54 +01:00
hypervisor.c
init.c
isa.c isa: Call isa_bus_init before dependent ISA bus drivers register 2016-06-17 20:47:11 -07:00
Kconfig Driver core patches for 4.10-rc1 2016-12-13 11:42:18 -08:00
Makefile driver-core: add test module for asynchronous probing 2016-11-10 17:28:16 +01:00
map.c
memory.c memory_hotplug: make zone_can_shift() return a boolean value 2017-01-24 16:26:14 -08:00
module.c base: make module_create_drivers_dir race-free 2016-06-15 19:21:31 -07:00
node.c treewide: replace obsolete _refok by __ref 2016-08-02 17:31:41 -04:00
pinctrl.c driver: base: pinctrl: return error from pinctrl_bind_pins() 2016-09-13 23:02:59 +02:00
platform-msi.c genirq/msi: Add cpumask allocation to alloc_msi_entry 2016-09-14 22:11:08 +02:00
platform.c driver-core: platform: Catch errors from calls to irq_get_irq_data 2016-09-27 12:30:37 +02:00
property.c device property: Add function to search for named child of device 2016-06-26 12:39:03 +01:00
soc.c base: soc: Check for NULL SoC device attributes 2016-11-10 10:10:33 +01:00
syscore.c
topology.c drivers base/topology: Convert to hotplug state machine 2016-11-09 23:45:29 +01:00
transport_class.c