[PATCH v2 3/3] mm/vmstat.c: do not show lowmem reserve protection information of empty zone

From: Baoquan He
Date: Thu Apr 02 2020 - 10:01:39 EST


Because the lowmem reserve protection of a zone can't tell anything if
the zone is empty, except of adding one more line in /proc/zoneinfo.

Let's remove it from that zone's showing.

Signed-off-by: Baoquan He <bhe@xxxxxxxxxx>
---
mm/vmstat.c | 12 ++++++------
1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/mm/vmstat.c b/mm/vmstat.c
index 96d21a792b57..6fd1407f4632 100644
--- a/mm/vmstat.c
+++ b/mm/vmstat.c
@@ -1590,6 +1590,12 @@ static void zoneinfo_show_print(struct seq_file *m, pg_data_t *pgdat,
zone->present_pages,
zone_managed_pages(zone));

+ /* If unpopulated, no other information is useful */
+ if (!populated_zone(zone)) {
+ seq_putc(m, '\n');
+ return;
+ }
+
seq_printf(m,
"\n protection: (%ld",
zone->lowmem_reserve[0]);
@@ -1597,12 +1603,6 @@ static void zoneinfo_show_print(struct seq_file *m, pg_data_t *pgdat,
seq_printf(m, ", %ld", zone->lowmem_reserve[i]);
seq_putc(m, ')');

- /* If unpopulated, no other information is useful */
- if (!populated_zone(zone)) {
- seq_putc(m, '\n');
- return;
- }
-
for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
seq_printf(m, "\n %-12s %lu", zone_stat_name(i),
zone_page_state(zone, i));
--
2.17.2