From 851ae6424697d1c4f085cb878c88168923ebcad1 Mon Sep 17 00:00:00 2001 From: Huang Ying Date: Mon, 17 Apr 2023 07:59:29 +0800 Subject: migrate_pages_batch: fix statistics for longterm pin retry In commit fd4a7ac32918 ("mm: migrate: try again if THP split is failed due to page refcnt"), if the THP splitting fails due to page reference count, we will retry to improve migration successful rate. But the failed splitting is counted as migration failure and migration retry, which will cause duplicated failure counting. So, in this patch, this is fixed via undoing the failure counting if we decide to retry. The patch is tested via failure injection. Link: https://lkml.kernel.org/r/20230416235929.1040194-1-ying.huang@intel.com Fixes: fd4a7ac32918 ("mm: migrate: try again if THP split is failed due to page refcnt") Signed-off-by: "Huang, Ying" Reviewed-by: Baolin Wang Cc: Alistair Popple Cc: David Hildenbrand Cc: Yang Shi Cc: Zi Yan Signed-off-by: Andrew Morton --- mm/migrate.c | 3 +++ 1 file changed, 3 insertions(+) (limited to 'mm') diff --git a/mm/migrate.c b/mm/migrate.c index 41f2154d66ad..5d95e09b1618 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -1710,6 +1710,9 @@ static int migrate_pages_batch(struct list_head *from, new_page_t get_new_page, large_retry++; thp_retry += is_thp; nr_retry_pages += nr_pages; + /* Undo duplicated failure counting. */ + nr_large_failed--; + stats->nr_thp_failed -= is_thp; break; } } -- cgit v1.2.3