From: Liu Shixin <liushixin2@xxxxxxxxxx>
Subject: mm/page_alloc: fix counting of managed_pages
commit f63661566fad ("mm/page_alloc.c: clear out zone->lowmem_reserve[] if
the zone is empty") clears out zone->lowmem_reserve[] if zone is empty.
But when zone is not empty and sysctl_lowmem_reserve_ratio[i] is set to
zero, zone_managed_pages(zone) is not counted in the managed_pages either.
This is inconsistent with the description of lowmem_reserve, so fix it.
Link: https://lkml.kernel.org/r/20210527125707.3760259-1-liushixin2@xxxxxxxxxx
Fixes: f63661566fad ("mm/page_alloc.c: clear out zone->lowmem_reserve[] if the zone is empty")
Signed-off-by: Liu Shixin <liushixin2@xxxxxxxxxx>
Reported-by: yangerkun <yangerkun@xxxxxxxxxx>
Reviewed-by: Baoquan He <bhe@xxxxxxxxxx>
Acked-by: David Hildenbrand <david@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/page_alloc.c | 12 ++++++------
1 file changed, 6 insertions(+), 6 deletions(-)
--- a/mm/page_alloc.c~mm-page_alloc-fix-counting-of-managed_pages
+++ a/mm/page_alloc.c
@@ -8240,14 +8240,14 @@ static void setup_per_zone_lowmem_reserv
unsigned long managed_pages = 0;
for (j = i + 1; j < MAX_NR_ZONES; j++) {
- if (clear) {
- zone->lowmem_reserve[j] = 0;
- } else {
- struct zone *upper_zone = &pgdat->node_zones[j];
+ struct zone *upper_zone = &pgdat->node_zones[j];
+
+ managed_pages += zone_managed_pages(upper_zone);
- managed_pages += zone_managed_pages(upper_zone);
+ if (clear)
+ zone->lowmem_reserve[j] = 0;
+ else
zone->lowmem_reserve[j] = managed_pages / ratio;
- }
}
}
}
_
