[PATCH 2.6.21-rc1-mm1] add check_highest_zone to build_zonelists_in_zone_order

[Lee Schermerhorn <Lee.Schermerhorn@hp.com>]

[PATCH 2.6.21-rc1-mm1] add check_highest_zone to build_zonelists_in_zone_order

We missed this in the "change zone order" series.  We need to record
the highest populated zone, just as build_zonelists_node() does.
Memory policies apply only to this zone.  Without this, we'll be
applying policy to all zones, including DMA, I think.  Not having
thought about it much, I can't claim to understand the downside of
doing so.

Also, display selected "policy zone" during boot or reconfig
of zonelist order, if 'NUMA.  Inquiring minds [might] want to know...

Cleanup:  remove stale comment in set_zonelist_order()

Signed-off-by:  Lee Schermerhorn <lee.schermerhorn@hp.com>

 mm/page_alloc.c |   10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

Index: Linux/mm/page_alloc.c
===================================================================
--- Linux.orig/mm/page_alloc.c	2007-05-16 10:32:20.000000000 -0400
+++ Linux/mm/page_alloc.c	2007-05-16 15:18:53.000000000 -0400
@@ -2037,7 +2037,7 @@ static char zonelist_order_name[3][8] = 
 
 
 #ifdef CONFIG_NUMA
-/* The vaule user specified ....changed by config */
+/* The value user specified ....changed by config */
 static int user_zonelist_order = ZONELIST_ORDER_DEFAULT;
 /* string for sysctl */
 #define NUMA_ZONELIST_ORDER_LEN	16
@@ -2215,8 +2215,10 @@ static void build_zonelists_in_zone_orde
 			for (j = 0; j < nr_nodes; j++) {
 				node = node_order[j];
 				z = &NODE_DATA(node)->node_zones[zone_type];
-				if (populated_zone(z))
+				if (populated_zone(z)) {
 					zonelist->zones[pos++] = z;
+					check_highest_zone(zone_type);
+				}
 			}
 		}
 		zonelist->zones[pos] = NULL;
@@ -2278,7 +2280,6 @@ static int default_zonelist_order(void)
 
 static void set_zonelist_order(void)
 {
-	/* dummy, just select node order. */
 	if (user_zonelist_order == ZONELIST_ORDER_DEFAULT)
 		current_zonelist_order = default_zonelist_order();
 	else
@@ -2458,6 +2459,9 @@ void build_all_zonelists(void)
 			zonelist_order_name[current_zonelist_order],
 			page_group_by_mobility_disabled ? "off" : "on",
 			vm_total_pages);
+#ifdef CONFIG_NUMA
+	printk("Policy zone:  %s\n", zone_names[policy_zone]);
+#endif
 }
 
 /*