[PATCH 4/5] mm/vmstat.c: move the per-node stats to the front of /proc/zoneinfo

[Baoquan He]

This moving makes the layout of /proc/zoneinfo more sensible. And there
are 4 zones at most currently, it doesn't need to scroll down much to get
to the 1st populated zone, even though the 1st populated zone is MOVABLE
zone.

Node 2, per-node stats
      nr_inactive_anon 48
      nr_active_anon 15454
...
      nr_foll_pin_acquired 0
      nr_foll_pin_released 0
Node 2, zone      DMA
  pages free     0
        min      0
        low      0
        high     0
        spanned  0
        present  0
        managed  0
Node 2, zone    DMA32
  pages free     0
        min      0
        low      0
        high     0
        spanned  0
        present  0
        managed  0
Node 2, zone   Normal
  pages free     0
        min      0
        low      0
        high     0
        spanned  0
        present  0
        managed  0
Node 2, zone  Movable
  pages free     196346
        min      3540
...
        managed  262144

Signed-off-by: Baoquan He <bhe@xxxxxxxxxx>
---
 mm/vmstat.c | 18 +++++++++++-------
 1 file changed, 11 insertions(+), 7 deletions(-)

diff --git a/mm/vmstat.c b/mm/vmstat.c
index 6fd1407f4632..4bbf9be786da 100644
--- a/mm/vmstat.c
+++ b/mm/vmstat.c
@@ -1567,13 +1567,6 @@ static void zoneinfo_show_print(struct seq_file *m, pg_data_t *pgdat,
 {
 	int i;
 	seq_printf(m, "Node %d, zone %8s", pgdat->node_id, zone->name);
-	if (is_zone_first_populated(pgdat, zone)) {
-		seq_printf(m, "\n  per-node stats");
-		for (i = 0; i < NR_VM_NODE_STAT_ITEMS; i++) {
-			seq_printf(m, "\n      %-12s %lu", node_stat_name(i),
-				   node_page_state(pgdat, i));
-		}
-	}
 	seq_printf(m,
 		   "\n  pages free     %lu"
 		   "\n        min      %lu"
@@ -1648,7 +1641,18 @@ static void zoneinfo_show_print(struct seq_file *m, pg_data_t *pgdat,
  */
 static int zoneinfo_show(struct seq_file *m, void *arg)
 {
+	int i;
 	pg_data_t *pgdat = (pg_data_t *)arg;
+
+	if (node_state(pgdat->node_id, N_MEMORY)) {
+		seq_printf(m, "Node %d, per-node stats", pgdat->node_id);
+		for (i = 0; i < NR_VM_NODE_STAT_ITEMS; i++) {
+			seq_printf(m, "\n      %-12s %lu", node_stat_name(i),
+				   node_page_state(pgdat, i));
+		}
+		seq_putc(m, '\n');
+	}
+
 	walk_zones_in_node(m, pgdat, false, false, zoneinfo_show_print);
 	return 0;
 }
-- 
2.17.2