[PATCH] mm/migrate: correct thp migration stats.

From: Zi Yan
Date: Thu Sep 17 2020 - 16:35:54 EST


From: Zi Yan <ziy@xxxxxxxxxx>

PageTransHuge returns true for both thp and hugetlb, so thp stats was
counting both thp and hugetlb migrations. Exclude hugetlb migration by
setting is_thp variable right.

Fixes: 1a5bae25e3cf ("mm/vmstat: add events for THP migration without split")
Signed-off-by: Zi Yan <ziy@xxxxxxxxxx>
Cc: Daniel Jordan <daniel.m.jordan@xxxxxxxxxx>
Cc: Anshuman Khandual <anshuman.khandual@xxxxxxx>
---
mm/migrate.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mm/migrate.c b/mm/migrate.c
index 941b89383cf3..d1ad964165e5 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -1445,7 +1445,7 @@ int migrate_pages(struct list_head *from, new_page_t get_new_page,
* Capture required information that might get lost
* during migration.
*/
- is_thp = PageTransHuge(page);
+ is_thp = PageTransHuge(page) && !PageHuge(page);
nr_subpages = thp_nr_pages(page);
cond_resched();

--
2.28.0