memcg: fix node_state handling

This should be N_NORMAL_MEMORY.

N_NORMAL_MEMORY is "true" if a node has memory for the kernel.  N_HIGH_MEMORY
is "true" if a node has memory for HIGHMEM.  (If CONFIG_HIGHMEM=n, always
"true")

This check is used for testing whether we can use kmalloc_node() on a node.
Then, if there is a node which only contains HIGHMEM, the system will call
kmalloc_node() which doesn't contain memory for the kernel.  If it happens
under SLUB, the kernel will panic.  I think this only happens on x86_32-numa.

Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/memcontrol.c

@@ -978,7 +978,7 @@ static int alloc_mem_cgroup_per_zone_info(struct mem_cgroup *mem, int node)
 {
 	struct mem_cgroup_per_node *pn;
 	struct mem_cgroup_per_zone *mz;
-	int zone;
+	int zone, tmp = node;
 	/*
 	 * This routine is called against possible nodes.
 	 * But it's BUG to call kmalloc() against offline node.
@@ -987,10 +987,9 @@ static int alloc_mem_cgroup_per_zone_info(struct mem_cgroup *mem, int node)
 	 *       never be onlined. It's better to use memory hotplug callback
 	 *       function.
 	 */
-	if (node_state(node, N_HIGH_MEMORY))
+	if (!node_state(node, N_NORMAL_MEMORY))
-		pn = kmalloc_node(sizeof(*pn), GFP_KERNEL, node);
+		tmp = -1;
-	else
+	pn = kmalloc_node(sizeof(*pn), GFP_KERNEL, tmp);
-		pn = kmalloc(sizeof(*pn), GFP_KERNEL);
 	if (!pn)
 		return 1;