[PATCH 2/4] mm/page_alloc: correct highmem memory statistics

[js1304]

From: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx>

ZONE_MOVABLE could be treated as highmem so we need to consider it for
accurate statistics. And, in following patches, ZONE_CMA will be
introduced and it can be treated as highmem, too. So, instead of
manually adding stat of ZONE_MOVABLE, looping all zones and check whether
the zone is highmem or not and add stat of the zone which can be treated
as highmem.

Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx>
---
 mm/page_alloc.c | 19 ++++++++++++++-----
 1 file changed, 14 insertions(+), 5 deletions(-)

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 437a934..173e616 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -3897,6 +3897,8 @@ void si_meminfo_node(struct sysinfo *val, int nid)
 {
 	int zone_type;		/* needs to be signed */
 	unsigned long managed_pages = 0;
+	unsigned long managed_highpages = 0;
+	unsigned long free_highpages = 0;
 	pg_data_t *pgdat = NODE_DATA(nid);
 
 	for (zone_type = 0; zone_type < MAX_NR_ZONES; zone_type++)
@@ -3905,12 +3907,19 @@ void si_meminfo_node(struct sysinfo *val, int nid)
 	val->sharedram = node_page_state(nid, NR_SHMEM);
 	val->freeram = node_page_state(nid, NR_FREE_PAGES);
 #ifdef CONFIG_HIGHMEM
-	val->totalhigh = pgdat->node_zones[ZONE_HIGHMEM].managed_pages;
-	val->freehigh = zone_page_state(&pgdat->node_zones[ZONE_HIGHMEM],
-			NR_FREE_PAGES);
+	for (zone_type = 0; zone_type < MAX_NR_ZONES; zone_type++) {
+		struct zone *zone = &pgdat->node_zones[zone_type];
+
+		if (is_highmem(zone)) {
+			managed_highpages += zone->managed_pages;
+			free_highpages += zone_page_state(zone, NR_FREE_PAGES);
+		}
+	}
+	val->totalhigh = managed_highpages;
+	val->freehigh = free_highpages;
 #else
-	val->totalhigh = 0;
-	val->freehigh = 0;
+	val->totalhigh = managed_highpages;
+	val->freehigh = free_highpages;
 #endif
 	val->mem_unit = PAGE_SIZE;
 }
-- 
1.9.1