From: Baoquan He <bhe@xxxxxxxxxx> Subject: Revert "mm/vmstat.c: do not show lowmem reserve protection information of empty zone" This reverts commit 26e7deadaae175. Sonny reported that one of their tests started failing on the latest kernel on their Chrome OS platform. The root cause is that the above commit removed the protection line of empty zone, while the parser used in the test relies on the protection line to mark the end of each zone. Let's revert it to avoid breaking userspace testing or applications. Link: http://lkml.kernel.org/r/20200811075412.12872-1-bhe@xxxxxxxxxx Fixes: 26e7deadaae175 ("mm/vmstat.c: do not show lowmem reserve protection information of empty zone)" Signed-off-by: Baoquan He <bhe@xxxxxxxxxx> Reported-by: Sonny Rao <sonnyrao@xxxxxxxxxxxx> Reviewed-by: David Hildenbrand <david@xxxxxxxxxx> Acked-by: David Rientjes <rientjes@xxxxxxxxxx> Cc: <stable@xxxxxxxxxxxxxxx> [5.8.x] Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/vmstat.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) --- a/mm/vmstat.c~revert-mm-vmstatc-do-not-show-lowmem-reserve-protection-information-of-empty-zone +++ a/mm/vmstat.c @@ -1642,12 +1642,6 @@ static void zoneinfo_show_print(struct s 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]); @@ -1655,6 +1649,12 @@ static void zoneinfo_show_print(struct s 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)); _
