[PATCH -V2 7/7] migrate_pages(): fix failure counting for retry

Huang Ying
2022-07-11T08:50:19Z

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@intel.com>
Fixes: 5984fabb6e82 ("mm: move_pages: report the number of non-attempted pages")
Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Zi Yan <ziy@nvidia.com>
Cc: Yang Shi <shy828301@gmail.com>
---
mm/migrate.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/mm/migrate.c b/mm/migrate.c
index 557708ce13a1..cee6fc5a2d31 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -1345,6 +1345,7 @@ 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;
@@ -1365,6 +1366,7 @@ 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) {
/*
@@ -1439,7 +1441,7 @@ 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
@@ -1455,6 +1457,7 @@ 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;
@@ -1481,6 +1484,7 @@ 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