at read: contains online/offline state of memory.
at write: user can specify "online_kernel",
"online_movable", "online", "offline" command
- which will be performed on al sections in the block.
+ which will be performed on all sections in the block.
'phys_device' : read-only: designed to show the name of physical memory
device. This is not well implemented now.
'removable' : read-only: contains an integer value indicating
4.2 Notify memory hot-add event by hand
------------
-In some environments, especially virtualized environment, firmware will not
-notify memory hotplug event to the kernel. For such environment, "probe"
-interface is supported. This interface depends on CONFIG_ARCH_MEMORY_PROBE.
-
-Now, CONFIG_ARCH_MEMORY_PROBE is supported only by powerpc but it does not
-contain highly architecture codes. Please add config if you need "probe"
-interface.
+On powerpc, the firmware does not notify a memory hotplug event to the kernel.
+Therefore, "probe" interface is supported to notify the event to the kernel.
+This interface depends on CONFIG_ARCH_MEMORY_PROBE.
+
+CONFIG_ARCH_MEMORY_PROBE is supported on powerpc only. On x86, this config
+option is disabled by default since ACPI notifies a memory hotplug event to
+the kernel, which performs its hotplug operation as the result. Please
+enable this option if you need the "probe" interface for testing purposes
+on x86.
Probe interface is located at
/sys/devices/system/memory/probe