The patch adds node_set_offline() and unregister_one_node() to remove_memory()
for removing sysfs file of node.

CC: Len Brown <redacted>
CC: Benjamin Herrenschmidt <benh@kernel.crashing.org>
CC: Paul Mackerras <redacted>
CC: Christoph Lameter <redacted>
Cc: Minchan Kim <redacted>
CC: Andrew Morton <akpm@linux-foundation.org>
CC: KOSAKI Motohiro <redacted>
CC: Wen Congyang <redacted>
Signed-off-by: Yasuaki Ishimatsu <redacted>

---
 mm/memory_hotplug.c |    5 +++++
 1 file changed, 5 insertions(+)

Index: linux-3.5-rc4/mm/memory_hotplug.c
===================================================================

--- linux-3.5-rc4.orig/mm/memory_hotplug.c	2012-06-26 14:32:03.630368866 +0900
+++ linux-3.5-rc4/mm/memory_hotplug.c	2012-06-26 14:39:58.090437374 +0900

@@ -702,6 +702,11 @@ int remove_memory(int nid, u64 start, u6
 	/* remove memmap entry */
 	firmware_map_remove(start, start + size, "System RAM");

+	if (!node_present_pages(nid)) {
+		node_set_offline(nid);
+		unregister_one_node(nid);
+	}
+
 	__remove_pages(start >> PAGE_SHIFT, size >> PAGE_SHIFT);
 	unlock_memory_hotplug();
 	return 0;