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authorZhang Zhen <zhenzhang.zhang@huawei.com>2014-10-09 15:26:31 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2014-10-09 22:25:52 -0400
commited2f240094f900833ac06f533ab8bbcf0a1e8199 (patch)
treea29d18bd9463645fa6ecdab3dd90945f861097d2 /Documentation
parentcc71aba348906ff93a4ad2f600045ee2d1ecc291 (diff)
memory-hotplug: add sysfs valid_zones attribute
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 <zhenzhang.zhang@huawei.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: David Rientjes <rientjes@google.com> Cc: Toshi Kani <toshi.kani@hp.com> Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Wang Nan <wangnan0@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/ABI/testing/sysfs-devices-memory8
-rw-r--r--Documentation/memory-hotplug.txt11
2 files changed, 18 insertions, 1 deletions
diff --git a/Documentation/ABI/testing/sysfs-devices-memory b/Documentation/ABI/testing/sysfs-devices-memory
index 7405de26ee60..deef3b5723cf 100644
--- a/Documentation/ABI/testing/sysfs-devices-memory
+++ b/Documentation/ABI/testing/sysfs-devices-memory
@@ -61,6 +61,14 @@ Users: hotplug memory remove tools
http://www.ibm.com/developerworks/wikis/display/LinuxP/powerpc-utils
+What: /sys/devices/system/memory/memoryX/valid_zones
+Date: July 2014
+Contact: Zhang Zhen <zhenzhang.zhang@huawei.com>
+Description:
+ The file /sys/devices/system/memory/memoryX/valid_zones is
+ read-only and is designed to show which zone this memory
+ block can be onlined to.
+
What: /sys/devices/system/memoryX/nodeY
Date: October 2009
Contact: Linux Memory Management list <linux-mm@kvack.org>
diff --git a/Documentation/memory-hotplug.txt b/Documentation/memory-hotplug.txt
index 45134dc23854..ea03abfc97e9 100644
--- a/Documentation/memory-hotplug.txt
+++ b/Documentation/memory-hotplug.txt
@@ -155,6 +155,7 @@ Under each memory block, you can see 4 files:
/sys/devices/system/memory/memoryXXX/phys_device
/sys/devices/system/memory/memoryXXX/state
/sys/devices/system/memory/memoryXXX/removable
+/sys/devices/system/memory/memoryXXX/valid_zones
'phys_index' : read-only and contains memory block id, same as XXX.
'state' : read-write
@@ -170,6 +171,15 @@ Under each memory block, you can see 4 files:
block is removable and a value of 0 indicates that
it is not removable. A memory block is removable only if
every section in the block is removable.
+'valid_zones' : read-only: designed to show which zones this memory block
+ can be onlined to.
+ The first column shows it's default zone.
+ "memory6/valid_zones: Normal Movable" shows this memoryblock
+ can be onlined to ZONE_NORMAL by default and to ZONE_MOVABLE
+ by online_movable.
+ "memory7/valid_zones: Movable Normal" shows this memoryblock
+ can be onlined to ZONE_MOVABLE by default and to ZONE_NORMAL
+ by online_kernel.
NOTE:
These directories/files appear after physical memory hotplug phase.
@@ -408,7 +418,6 @@ node if necessary.
- allowing memory hot-add to ZONE_MOVABLE. maybe we need some switch like
sysctl or new control file.
- showing memory block and physical device relationship.
- - showing memory block is under ZONE_MOVABLE or not
- test and make it better memory offlining.
- support HugeTLB page migration and offlining.
- memmap removing at memory offline.