1 files changed, 17 insertions, 10 deletions

diff --git a/mm/vmstat.c b/mm/vmstat.c
index 828a36ea0584..a828b17ced1a 100644
--- a/mm/vmstat.c
+++ b/mm/vmstat.c
@@ -1124,8 +1124,12 @@ static void frag_stop(struct seq_file *m, void *arg)
 {
 }
 
-/* Walk all the zones in a node and print using a callback */
+/*
+ * Walk zones in a node and print using a callback.
+ * If @assert_populated is true, only use callback for zones that are populated.
+ */
 static void walk_zones_in_node(struct seq_file *m, pg_data_t *pgdat,
+		bool assert_populated,
 		void (*print)(struct seq_file *m, pg_data_t *, struct zone *))
 {
 	struct zone *zone;
@@ -1133,7 +1137,7 @@ static void walk_zones_in_node(struct seq_file *m, pg_data_t *pgdat,
 	unsigned long flags;
 
 	for (zone = node_zones; zone - node_zones < MAX_NR_ZONES; ++zone) {
-		if (!populated_zone(zone))
+		if (assert_populated && !populated_zone(zone))
 			continue;
 
 		spin_lock_irqsave(&zone->lock, flags);
@@ -1161,7 +1165,7 @@ static void frag_show_print(struct seq_file *m, pg_data_t *pgdat,
 static int frag_show(struct seq_file *m, void *arg)
 {
 	pg_data_t *pgdat = (pg_data_t *)arg;
-	walk_zones_in_node(m, pgdat, frag_show_print);
+	walk_zones_in_node(m, pgdat, true, frag_show_print);
 	return 0;
 }
 
@@ -1202,7 +1206,7 @@ static int pagetypeinfo_showfree(struct seq_file *m, void *arg)
 		seq_printf(m, "%6d ", order);
 	seq_putc(m, '\n');
 
-	walk_zones_in_node(m, pgdat, pagetypeinfo_showfree_print);
+	walk_zones_in_node(m, pgdat, true, pagetypeinfo_showfree_print);
 
 	return 0;
 }
@@ -1254,7 +1258,7 @@ static int pagetypeinfo_showblockcount(struct seq_file *m, void *arg)
 	for (mtype = 0; mtype < MIGRATE_TYPES; mtype++)
 		seq_printf(m, "%12s ", migratetype_names[mtype]);
 	seq_putc(m, '\n');
-	walk_zones_in_node(m, pgdat, pagetypeinfo_showblockcount_print);
+	walk_zones_in_node(m, pgdat, true, pagetypeinfo_showblockcount_print);
 
 	return 0;
 }
@@ -1280,7 +1284,7 @@ static void pagetypeinfo_showmixedcount(struct seq_file *m, pg_data_t *pgdat)
 		seq_printf(m, "%12s ", migratetype_names[mtype]);
 	seq_putc(m, '\n');
 
-	walk_zones_in_node(m, pgdat, pagetypeinfo_showmixedcount_print);
+	walk_zones_in_node(m, pgdat, true, pagetypeinfo_showmixedcount_print);
 #endif /* CONFIG_PAGE_OWNER */
 }
 
@@ -1430,12 +1434,15 @@ static void zoneinfo_show_print(struct seq_file *m, pg_data_t *pgdat,
 }
 
 /*
- * Output information about zones in @pgdat.
+ * Output information about zones in @pgdat.  All zones are printed regardless
+ * of whether they are populated or not: lowmem_reserve_ratio operates on the
+ * set of all zones and userspace would not be aware of such zones if they are
+ * suppressed here (zoneinfo displays the effect of lowmem_reserve_ratio).
  */
 static int zoneinfo_show(struct seq_file *m, void *arg)
 {
 	pg_data_t *pgdat = (pg_data_t *)arg;
-	walk_zones_in_node(m, pgdat, zoneinfo_show_print);
+	walk_zones_in_node(m, pgdat, false, zoneinfo_show_print);
 	return 0;
 }
 
@@ -1841,7 +1848,7 @@ static int unusable_show(struct seq_file *m, void *arg)
 	if (!node_state(pgdat->node_id, N_MEMORY))
 		return 0;
 
-	walk_zones_in_node(m, pgdat, unusable_show_print);
+	walk_zones_in_node(m, pgdat, true, unusable_show_print);
 
 	return 0;
 }
@@ -1893,7 +1900,7 @@ static int extfrag_show(struct seq_file *m, void *arg)
 {
 	pg_data_t *pgdat = (pg_data_t *)arg;
 
-	walk_zones_in_node(m, pgdat, extfrag_show_print);
+	walk_zones_in_node(m, pgdat, true, extfrag_show_print);
 
 	return 0;
 }