arch, mm: filter disallowed nodes from arch specific show_mem functions

Architectures that implement their own show_mem() function did not pass
the filter argument to show_free_areas() to appropriately avoid emitting
the state of nodes that are disallowed in the current context.  This patch
now passes the filter argument to show_free_areas() so those nodes are now
avoided.

This patch also removes the show_free_areas() wrapper around
__show_free_areas() and converts existing callers to pass an empty filter.

ia64 emits additional information for each node, so skip_free_areas_zone()
must be made global to filter disallowed nodes and it is converted to use
a nid argument rather than a zone for this use case.

Signed-off-by: David Rientjes <rientjes@google.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Kyle McMartin <kyle@mcmartin.ca>
Cc: Helge Deller <deller@gmx.de>
Cc: James Bottomley <jejb@parisc-linux.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/page_alloc.c

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 9d5498e..b144752 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -2473,10 +2473,10 @@
 #endif
 
 /*
- * Determine whether the zone's node should be displayed or not, depending on
- * whether SHOW_MEM_FILTER_NODES was passed to __show_free_areas().
+ * Determine whether the node should be displayed or not, depending on whether
+ * SHOW_MEM_FILTER_NODES was passed to show_free_areas().
  */
-static bool skip_free_areas_zone(unsigned int flags, const struct zone *zone)
+bool skip_free_areas_node(unsigned int flags, int nid)
 {
 	bool ret = false;
 
@@ -2484,8 +2484,7 @@
 		goto out;
 
 	get_mems_allowed();
-	ret = !node_isset(zone->zone_pgdat->node_id,
-				cpuset_current_mems_allowed);
+	ret = !node_isset(nid, cpuset_current_mems_allowed);
 	put_mems_allowed();
 out:
 	return ret;
@@ -2500,13 +2499,13 @@
  * Suppresses nodes that are not allowed by current's cpuset if
  * SHOW_MEM_FILTER_NODES is passed.
  */
-void __show_free_areas(unsigned int filter)
+void show_free_areas(unsigned int filter)
 {
 	int cpu;
 	struct zone *zone;
 
 	for_each_populated_zone(zone) {
-		if (skip_free_areas_zone(filter, zone))
+		if (skip_free_areas_node(filter, zone_to_nid(zone)))
 			continue;
 		show_node(zone);
 		printk("%s per-cpu:\n", zone->name);
@@ -2549,7 +2548,7 @@
 	for_each_populated_zone(zone) {
 		int i;
 
-		if (skip_free_areas_zone(filter, zone))
+		if (skip_free_areas_node(filter, zone_to_nid(zone)))
 			continue;
 		show_node(zone);
 		printk("%s"
@@ -2618,7 +2617,7 @@
 	for_each_populated_zone(zone) {
  		unsigned long nr[MAX_ORDER], flags, order, total = 0;
 
-		if (skip_free_areas_zone(filter, zone))
+		if (skip_free_areas_node(filter, zone_to_nid(zone)))
 			continue;
 		show_node(zone);
 		printk("%s: ", zone->name);
@@ -2639,11 +2638,6 @@
 	show_swap_cache_info();
 }
 
-void show_free_areas(void)
-{
-	__show_free_areas(0);
-}
-
 static void zoneref_set_zone(struct zone *zone, struct zoneref *zoneref)
 {
 	zoneref->zone = zone;