From: Liu Shixin <liushixin2@huawei.com> ohos inclusion category: bugfix issue: #I3ZXZF CVE: NA ------------------------------------------------- The commit f63661566fad (mm/page_alloc.c: clear out zone->lowmem_reserve[] if the zone is empty) clear 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 lowmen_reserve, so fix it. Fixes: f63661566fad ("mm/page_alloc.c: clear out zone->lowmem_reserve[] if the zone is empty") Reported-by: yangerkun <yangerkun@huawei.com> Signed-off-by: Liu Shixin <liushixin2@huawei.com> Reviewed-by: Kefeng Wang <wangkefeng.wang@huawei.com> Signed-off-by: Chen Jun <chenjun102@huawei.com> Signed-off-by: Yu Changchun <yuchangchun1@huawei.com> --- mm/page_alloc.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) diff --git a/mm/page_alloc.c b/mm/page_alloc.c index dc4cc71235aa..c72ecf5c9e36 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -7796,14 +7796,14 @@ static void setup_per_zone_lowmem_reserve(void) 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; - } } } } -- 2.22.0