[PATCH v2 0/2] Add help info for CONFIG_MOVABLE_NODE and disable is by default

[PATCH v2 0/2] Add help info for CONFIG_MOVABLE_NODE and disable is by default

[Tang Chen]

The first patch adds help info for CONFIG_MOVABLE_NODE option.
The second patch disable this option by default.

change log v1 -> v2:
Fix spelling comments from Ingo.

Tang Chen (2):
  memory-hotplug: Add help info for CONFIG_MOVABLE_NODE option
  memory-hotplug: Disable CONFIG_MOVABLE_NODE option by default.

 mm/Kconfig |   12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

-- 
1.7.10.1

[PATCH v2 1/2] memory-hotplug: Add help info for CONFIG_MOVABLE_NODE option

[Tang Chen]

This patch adds help info for CONFIG_MOVABLE_NODE option.

This option allows user to online all memory of a node as movable
memory. So that the whole node can be hotpluged. Users who don't
use hotplug feature are also fine with this option on since they
won't online memory as movable.

Signed-off-by: Tang Chen <tangchen@cn.fujitsu.com>
Reviewed-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Acked-by: Ingo Molnar <mingo@kernel.org>
---
 mm/Kconfig |   10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/mm/Kconfig b/mm/Kconfig
index 71259e0..4913333 100644
--- a/mm/Kconfig
+++ b/mm/Kconfig
@@ -150,6 +150,16 @@ config MOVABLE_NODE
 	depends on X86_64
 	depends on NUMA
 	depends on BROKEN
+	help
+	  Allow a node to have only movable memory. Pages used by the kernel,
+	  such as direct mapping pages can not be migrated. So the corresponding
+	  memory device can not be hotplugged. This option allows users to online
+	  all the memory of a node as movable memory so that the whole node can
+	  be hot-unplugged. Users who don't use the hotplug feature are fine
+	  with this option on since they don't online memory as movable.
+
+	  Say Y here if you want to hotplug a whole node.
+	  Say N here if you want kernel to use memory on all nodes evenly.
 
 # eventually, we can have this option just 'select SPARSEMEM'
 config MEMORY_HOTPLUG
-- 
1.7.10.1

[PATCH v2 2/2] memory-hotplug: Disable CONFIG_MOVABLE_NODE option by default.

[Tang Chen]

This patch set CONFIG_MOVABLE_NODE to "default n" instead of
"depends on BROKEN".

Signed-off-by: Tang Chen <tangchen@cn.fujitsu.com>
Reviewed-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
---
 mm/Kconfig |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mm/Kconfig b/mm/Kconfig
index 4913333..bbd6bfa 100644
--- a/mm/Kconfig
+++ b/mm/Kconfig
@@ -149,7 +149,7 @@ config MOVABLE_NODE
 	depends on NO_BOOTMEM
 	depends on X86_64
 	depends on NUMA
-	depends on BROKEN
+	default n
 	help
 	  Allow a node to have only movable memory. Pages used by the kernel,
 	  such as direct mapping pages can not be migrated. So the corresponding
-- 
1.7.10.1

Re: [PATCH v2 2/2] memory-hotplug: Disable CONFIG_MOVABLE_NODE option by default.

[David Rientjes]

On Mon, 17 Dec 2012, Tang Chen wrote:

> This patch set CONFIG_MOVABLE_NODE to "default n" instead of
> "depends on BROKEN".
> 
> Signed-off-by: Tang Chen <tangchen@cn.fujitsu.com>
> Reviewed-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>

It's fine to change the default, but what's missing here is a rationale 
for no longer making it depend on CONFIG_BROKEN.