The patch titled
Subject: mm/migrate.c: handle freed page at the first place
has been removed from the -mm tree. Its filename was
mm-migrate-handle-freed-page-at-the-first-place.patch
This patch was dropped because it was merged into mainline or a subsystem tree
------------------------------------------------------
From: Yang Shi <yang.shi@xxxxxxxxxxxxxxxxx>
Subject: mm/migrate.c: handle freed page at the first place
When doing migration if the freed page is met, we just return without
migrating it since it is pointless to migrate a freed page. But, the
current code allocates target page unconditionally before handling freed
page, if the page is freed, the newly allocated will be just freed. It
doesn't make too much sense and is just a waste of time although migrating
freed page is rare.
So, handle freed page at the before that to avoid unnecessary page
allocation and free.
Link: http://lkml.kernel.org/r/1573755869-106954-1-git-send-email-yang.shi@xxxxxxxxxxxxxxxxx
Signed-off-by: Yang Shi <yang.shi@xxxxxxxxxxxxxxxxx>
Acked-by: Michal Hocko <mhocko@xxxxxxxx>
Reviewed-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Mel Gorman <mgorman@xxxxxxxxxxxxxxxxxxx>
Cc: Vlastimil Babka <vbabka@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/migrate.c | 14 +++++---------
1 file changed, 5 insertions(+), 9 deletions(-)
--- a/mm/migrate.c~mm-migrate-handle-freed-page-at-the-first-place
+++ a/mm/migrate.c
@@ -1168,15 +1168,11 @@ static ICE_noinline int unmap_and_move(n
enum migrate_reason reason)
{
int rc = MIGRATEPAGE_SUCCESS;
- struct page *newpage;
+ struct page *newpage = NULL;
if (!thp_migration_supported() && PageTransHuge(page))
return -ENOMEM;
- newpage = get_new_page(page, private);
- if (!newpage)
- return -ENOMEM;
-
if (page_count(page) == 1) {
/* page was freed from under us. So we are done. */
ClearPageActive(page);
@@ -1187,13 +1183,13 @@ static ICE_noinline int unmap_and_move(n
__ClearPageIsolated(page);
unlock_page(page);
}
- if (put_new_page)
- put_new_page(newpage, private);
- else
- put_page(newpage);
goto out;
}
+ newpage = get_new_page(page, private);
+ if (!newpage)
+ return -ENOMEM;
+
rc = __unmap_and_move(page, newpage, force, mode);
if (rc == MIGRATEPAGE_SUCCESS)
set_page_owner_migrate_reason(newpage, reason);
_
Patches currently in -mm which might be from yang.shi@xxxxxxxxxxxxxxxxx are
