From: Zhang Yanfei <zhangyan...@cn.fujitsu.com>

Since we already has config MOVABLE_NODE, and the boot option
movablenode is introduced as the boot-time switch to disable
the effects of CONFIG_MOVABLE_NODE=y when the system is booting.

So rename boot option movablenode to movable_node to match the
config MOVABLE_NODE. And also updates the description of MOVABLE_NODE
in mm/Kconfig and the description of movable_node in kernel doc.

Suggested-by: Ingo Molnar <mi...@kernel.org>
Signed-off-by: Zhang Yanfei <zhangyan...@cn.fujitsu.com>
---
 Documentation/kernel-parameters.txt |   16 ++--------------
 mm/Kconfig                          |   17 ++++++++++++-----
 mm/memory_hotplug.c                 |    6 +++---
 3 files changed, 17 insertions(+), 22 deletions(-)

diff --git a/Documentation/kernel-parameters.txt 
b/Documentation/kernel-parameters.txt
index a87e17e..953a533 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -1773,20 +1773,8 @@ bytes respectively. Such letter suffixes can also be 
entirely omitted.
                        that the amount of memory usable for all allocations
                        is not too small.
 
-       movablenode             [KNL,X86] This parameter enables/disables the
-                       kernel to arrange hotpluggable memory ranges recorded
-                       in ACPI SRAT(System Resource Affinity Table) as
-                       ZONE_MOVABLE. And these memory can be hot-removed when
-                       the system is up.
-                       By specifying this option, all the hotpluggable memory
-                       will be in ZONE_MOVABLE, which the kernel cannot use.
-                       This will cause NUMA performance down. For users who
-                       care about NUMA performance, just don't use it.
-                       If all the memory ranges in the system are hotpluggable,
-                       then the ones used by the kernel at early time, such as
-                       kernel code and data segments, initrd file and so on,
-                       won't be set as ZONE_MOVABLE, and won't be hotpluggable.
-                       Otherwise the kernel won't have enough memory to boot.
+       movable_node    [KNL,X86] Boot-time switch to disable the effects
+                       of CONFIG_MOVABLE_NODE=y. See mm/Kconfig for details.
 
        MTD_Partition=  [MTD]
                        Format: <name>,<region-number>,<size>,<offset>
diff --git a/mm/Kconfig b/mm/Kconfig
index ff6e820..8d4ebb0 100644
--- a/mm/Kconfig
+++ b/mm/Kconfig
@@ -153,11 +153,18 @@ config MOVABLE_NODE
        help
          Allow a node to have only movable memory.  Pages used by the kernel,
          such as direct mapping pages cannot be migrated.  So the corresponding
-         memory device cannot be hotplugged.  This option allows users to
-         online all the memory of a node as movable memory so that the whole
-         node can be hotplugged.  Users who don't use the memory hotplug
-         feature are fine with this option on since they don't online memory
-         as movable.
+         memory device cannot be hotplugged.  This option allows the following
+         two things:
+         - When the system is booting, node full of hotpluggable memory can
+         be arranged to have only movable memory so that the whole node can
+         be hotplugged. (need movable_node boot option specified).
+         - After the system is up, the option allows users to online all the
+         memory of a node as movable memory so that the whole node can be
+         hotplugged.
+
+         Users who don't use the memory hotplug feature are fine with this
+         option on since they don't specify movable_node boot option or 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.
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index b468f77..5e2aed9 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -1424,7 +1424,7 @@ static bool can_offline_normal(struct zone *zone, 
unsigned long nr_pages)
 }
 #endif /* CONFIG_MOVABLE_NODE */
 
-static int __init cmdline_parse_movablenode(char *p)
+static int __init cmdline_parse_movable_node(char *p)
 {
 #ifdef CONFIG_MOVABLE_NODE
        /*
@@ -1448,11 +1448,11 @@ static int __init cmdline_parse_movablenode(char *p)
         */
        memblock_set_bottom_up(true);
 #else
-       pr_warn("movablenode option not supported");
+       pr_warn("movable_node option not supported");
 #endif
        return 0;
 }
-early_param("movablenode", cmdline_parse_movablenode);
+early_param("movable_node", cmdline_parse_movable_node);
 
 /* check which state of node_states will be changed when offline memory */
 static void node_states_check_changes_offline(unsigned long nr_pages,
-- 
1.7.1
--
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