2022-07-11 09:10:02

by Huang, Ying

Subject: [PATCH -V2 4/7] migrate_pages(): fix failure counting for THP subpages retrying

If THP is failed to be migrated for -ENOSYS and -ENOMEM, the THP will
be split into thp_split_pages, and after other pages are migrated,
pages in thp_split_pages will be migrated with no_subpage_counting ==
true, because its failure have been counted already. If some pages in
thp_split_pages are retried during migration, we should not count
their failure if no_subpage_counting == true too. This is done this
patch to fix the failure counting for THP subpages retrying.

Signed-off-by: "Huang, Ying" <[email protected]>
Fixes: 5984fabb6e82 ("mm: move_pages: report the number of non-attempted pages")
Reviewed-by: Baolin Wang <[email protected]>
Cc: Zi Yan <[email protected]>
Cc: Yang Shi <[email protected]>
---
mm/migrate.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/mm/migrate.c b/mm/migrate.c
index 38e2c789a9c3..4bceba143db0 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -1477,7 +1477,8 @@ int migrate_pages(struct list_head *from, new_page_t get_new_page,
}
}
}
- nr_failed += retry;
+ if (!no_subpage_counting)
+ nr_failed += retry;
nr_thp_failed += thp_retry;
/*
* Try to migrate subpages of fail-to-migrate THPs, no nr_failed
--
2.30.2

2022-07-11 12:25:45

by Oscar Salvador

Subject: Re: [PATCH -V2 4/7] migrate_pages(): fix failure counting for THP subpages retrying

On Mon, Jul 11, 2022 at 04:49:45PM +0800, Huang Ying wrote:
> If THP is failed to be migrated for -ENOSYS and -ENOMEM, the THP will
> be split into thp_split_pages, and after other pages are migrated,
> pages in thp_split_pages will be migrated with no_subpage_counting ==
> true, because its failure have been counted already. If some pages in
> thp_split_pages are retried during migration, we should not count
> their failure if no_subpage_counting == true too. This is done this
> patch to fix the failure counting for THP subpages retrying.
>
> Signed-off-by: "Huang, Ying" <[email protected]>
> Fixes: 5984fabb6e82 ("mm: move_pages: report the number of non-attempted pages")
> Reviewed-by: Baolin Wang <[email protected]>
> Cc: Zi Yan <[email protected]>
> Cc: Yang Shi <[email protected]>

Reviewed-by: Oscar Salvador <[email protected]>


--
Oscar Salvador
SUSE Labs