[RFC PATCH v2 03/11] mm: khugepaged: add an order check for PMD-sized THP statistics

[Baolin Wang]

In order to support shmem mTHP collapse in the following patches, add
an PMD-sized THP order check to avoid PMD-sized THP statistics errors.

No functional changes.

Signed-off-by: Baolin Wang <baolin.wang@xxxxxxxxxxxxxxxxx>
---
 mm/khugepaged.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/mm/khugepaged.c b/mm/khugepaged.c
index 4adc8c6de062..0c8dfbd48410 100644
--- a/mm/khugepaged.c
+++ b/mm/khugepaged.c
@@ -2595,8 +2595,9 @@ static enum scan_result collapse_file(struct mm_struct *mm, unsigned long addr,
 
 	if (is_shmem) {
 		lruvec_stat_mod_folio(new_folio, NR_SHMEM, nr_pages);
-		lruvec_stat_mod_folio(new_folio, NR_SHMEM_THPS, HPAGE_PMD_NR);
-	} else {
+		if (is_pmd_order(order))
+			lruvec_stat_mod_folio(new_folio, NR_SHMEM_THPS, HPAGE_PMD_NR);
+	} else if (is_pmd_order(order)) {
 		lruvec_stat_mod_folio(new_folio, NR_FILE_THPS, HPAGE_PMD_NR);
 	}
 	lruvec_stat_mod_folio(new_folio, NR_FILE_PAGES, nr_pages);
-- 
2.47.3