+ mm-page_alloc-fix-counting-of-managed_pages.patch added to -mm tree

+ mm-page_alloc-fix-counting-of-managed_pages.patch added to -mm tree

[akpm]

The patch titled
     Subject: mm/page_alloc: fix counting of managed_pages
has been added to the -mm tree.  Its filename is
     mm-page_alloc-fix-counting-of-managed_pages.patch

This patch should soon appear at
    https://ozlabs.org/~akpm/mmots/broken-out/mm-page_alloc-fix-counting-of-managed_pages.patch
and later at
    https://ozlabs.org/~akpm/mmotm/broken-out/mm-page_alloc-fix-counting-of-managed_pages.patch

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------------------------------------------------------
From: Liu Shixin <liushixin2@huawei.com>
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@huawei.com
Fixes: f63661566fad ("mm/page_alloc.c: clear out zone->lowmem_reserve[] if the zone is empty")
Signed-off-by: Liu Shixin <liushixin2@huawei.com>
Reported-by: yangerkun <yangerkun@huawei.com>
Reviewed-by: Baoquan He <bhe@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 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
@@ -8214,14 +8214,14 @@ 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;
-				}
 			}
 		}
 	}
_

Patches currently in -mm which might be from liushixin2@huawei.com are

mm-page_alloc-fix-counting-of-managed_pages.patch
mm-debug_vm_pgtable-move-pmd-pud_huge_tests-out-of-config_transparent_hugepage.patch
mm-debug_vm_pgtable-remove-redundant-pfn_pmd-pte-and-fix-one-comment-mistake.patch