2 files changed, 14 insertions, 8 deletions

diff --git a/Documentation/memory-hotplug.txt b/Documentation/memory-hotplug.txt
index 8e5eacbdcfa3..8fd254c73589 100644
--- a/Documentation/memory-hotplug.txt
+++ b/Documentation/memory-hotplug.txt
@@ -210,13 +210,15 @@ If memory device is found, memory hotplug code will be called.
 
 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
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index b32ebf92b0ce..2f9d95775d27 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -1344,8 +1344,12 @@ config ARCH_SELECT_MEMORY_MODEL
         depends on ARCH_SPARSEMEM_ENABLE
 
 config ARCH_MEMORY_PROBE
-        def_bool y
+        bool "Enable sysfs memory/probe interface"
         depends on X86_64 && MEMORY_HOTPLUG
+        help
+          This option enables a sysfs memory/probe interface for testing.
+          See Documentation/memory-hotplug.txt for more information.
+          If you are unsure how to answer this question, answer N.
 
 config ARCH_PROC_KCORE_TEXT
         def_bool y