[PATCH -V3 7/8] migrate_pages(): fix failure counting for retry

[Huang Ying]

After 10 retries, we will give up and the remaining pages will be
counted as failure in nr_failed and nr_thp_failed.  We should count
the failure in nr_failed_pages too.  This is done in this patch.

Signed-off-by: "Huang, Ying" <ying.huang@xxxxxxxxx>
Fixes: 5984fabb6e82 ("mm: move_pages: report the number of non-attempted pages")
Reviewed-by: Baolin Wang <baolin.wang@xxxxxxxxxxxxxxxxx>
Reviewed-by: Oscar Salvador <osalvador@xxxxxxx>
Cc: Zi Yan <ziy@xxxxxxxxxx>
Cc: Yang Shi <shy828301@xxxxxxxxx>
---
 mm/migrate.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/mm/migrate.c b/mm/migrate.c
index 81daa4dd3bb6..55fbf9669431 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -1413,6 +1413,7 @@ int migrate_pages(struct list_head *from, new_page_t get_new_page,
 	int thp_retry = 1;
 	int nr_failed = 0;
 	int nr_failed_pages = 0;
+	int nr_retry_pages = 0;
 	int nr_succeeded = 0;
 	int nr_thp_succeeded = 0;
 	int nr_thp_failed = 0;
@@ -1433,6 +1434,7 @@ int migrate_pages(struct list_head *from, new_page_t get_new_page,
 	for (pass = 0; pass < 10 && (retry || thp_retry); pass++) {
 		retry = 0;
 		thp_retry = 0;
+		nr_retry_pages = 0;
 
 		list_for_each_entry_safe(page, page2, from, lru) {
 			/*
@@ -1506,7 +1508,7 @@ int migrate_pages(struct list_head *from, new_page_t get_new_page,
 					nr_failed++;
 				}
 
-				nr_failed_pages += nr_subpages;
+				nr_failed_pages += nr_subpages + nr_retry_pages;
 				/*
 				 * There might be some subpages of fail-to-migrate THPs
 				 * left in thp_split_pages list. Move them back to migration
@@ -1522,6 +1524,7 @@ int migrate_pages(struct list_head *from, new_page_t get_new_page,
 					thp_retry++;
 				else
 					retry++;
+				nr_retry_pages += nr_subpages;
 				break;
 			case MIGRATEPAGE_SUCCESS:
 				nr_succeeded += nr_subpages;
@@ -1548,6 +1551,7 @@ int migrate_pages(struct list_head *from, new_page_t get_new_page,
 	if (!no_subpage_counting)
 		nr_failed += retry;
 	nr_thp_failed += thp_retry;
+	nr_failed_pages += nr_retry_pages;
 	/*
 	 * Try to migrate subpages of fail-to-migrate THPs, no nr_failed
 	 * counting in this round, since all subpages of a THP is counted
-- 
2.30.2