[PATCH 3/4] mm/highmem: make nr_free_highpages() handles all highmem zones by itself

[js1304]

From: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx>

nr_free_highpages() manually add statistics per each highmem zone
and return total value for them. Whenever we add a new highmem zone,
we need to consider this function and it's really troublesome. Make
it handles all highmem zones by itself.

Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx>
---
 mm/highmem.c | 12 ++++--------
 1 file changed, 4 insertions(+), 8 deletions(-)

diff --git a/mm/highmem.c b/mm/highmem.c
index 123bcd3..50b4ca6 100644
--- a/mm/highmem.c
+++ b/mm/highmem.c
@@ -112,16 +112,12 @@ EXPORT_PER_CPU_SYMBOL(__kmap_atomic_idx);
 
 unsigned int nr_free_highpages (void)
 {
-	pg_data_t *pgdat;
+	struct zone *zone;
 	unsigned int pages = 0;
 
-	for_each_online_pgdat(pgdat) {
-		pages += zone_page_state(&pgdat->node_zones[ZONE_HIGHMEM],
-			NR_FREE_PAGES);
-		if (zone_movable_is_highmem())
-			pages += zone_page_state(
-					&pgdat->node_zones[ZONE_MOVABLE],
-					NR_FREE_PAGES);
+	for_each_populated_zone(zone) {
+		if (is_highmem(zone))
+			pages += zone_page_state(zone, NR_FREE_PAGES);
 	}
 
 	return pages;
-- 
1.9.1