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-rw-r--r--Documentation/memory-hotplug.txt16
1 files changed, 13 insertions, 3 deletions
diff --git a/Documentation/memory-hotplug.txt b/Documentation/memory-hotplug.txt
index 168117bd6ee8..4c2ecf537a4a 100644
--- a/Documentation/memory-hotplug.txt
+++ b/Documentation/memory-hotplug.txt
@@ -124,7 +124,7 @@ config options.
124 This option can be kernel module too. 124 This option can be kernel module too.
125 125
126-------------------------------- 126--------------------------------
1273 sysfs files for memory hotplug 1274 sysfs files for memory hotplug
128-------------------------------- 128--------------------------------
129All sections have their device information under /sys/devices/system/memory as 129All sections have their device information under /sys/devices/system/memory as
130 130
@@ -138,11 +138,12 @@ For example, assume 1GiB section size. A device for a memory starting at
138(0x100000000 / 1Gib = 4) 138(0x100000000 / 1Gib = 4)
139This device covers address range [0x100000000 ... 0x140000000) 139This device covers address range [0x100000000 ... 0x140000000)
140 140
141Under each section, you can see 3 files. 141Under each section, you can see 4 files.
142 142
143/sys/devices/system/memory/memoryXXX/phys_index 143/sys/devices/system/memory/memoryXXX/phys_index
144/sys/devices/system/memory/memoryXXX/phys_device 144/sys/devices/system/memory/memoryXXX/phys_device
145/sys/devices/system/memory/memoryXXX/state 145/sys/devices/system/memory/memoryXXX/state
146/sys/devices/system/memory/memoryXXX/removable
146 147
147'phys_index' : read-only and contains section id, same as XXX. 148'phys_index' : read-only and contains section id, same as XXX.
148'state' : read-write 149'state' : read-write
@@ -150,10 +151,20 @@ Under each section, you can see 3 files.
150 at write: user can specify "online", "offline" command 151 at write: user can specify "online", "offline" command
151'phys_device': read-only: designed to show the name of physical memory device. 152'phys_device': read-only: designed to show the name of physical memory device.
152 This is not well implemented now. 153 This is not well implemented now.
154'removable' : read-only: contains an integer value indicating
155 whether the memory section is removable or not
156 removable. A value of 1 indicates that the memory
157 section is removable and a value of 0 indicates that
158 it is not removable.
153 159
154NOTE: 160NOTE:
155 These directories/files appear after physical memory hotplug phase. 161 These directories/files appear after physical memory hotplug phase.
156 162
163If CONFIG_NUMA is enabled the
164/sys/devices/system/memory/memoryXXX memory section
165directories can also be accessed via symbolic links located in
166the /sys/devices/system/node/node* directories. For example:
167/sys/devices/system/node/node0/memory9 -> ../../memory/memory9
157 168
158-------------------------------- 169--------------------------------
1594. Physical memory hot-add phase 1704. Physical memory hot-add phase
@@ -365,7 +376,6 @@ node if necessary.
365 - allowing memory hot-add to ZONE_MOVABLE. maybe we need some switch like 376 - allowing memory hot-add to ZONE_MOVABLE. maybe we need some switch like
366 sysctl or new control file. 377 sysctl or new control file.
367 - showing memory section and physical device relationship. 378 - showing memory section and physical device relationship.
368 - showing memory section and node relationship (maybe good for NUMA)
369 - showing memory section is under ZONE_MOVABLE or not 379 - showing memory section is under ZONE_MOVABLE or not
370 - test and make it better memory offlining. 380 - test and make it better memory offlining.
371 - support HugeTLB page migration and offlining. 381 - support HugeTLB page migration and offlining.