Revert "mm: make alloc_demote_folio externally invokable for migration"

This reverts commit a00ce85af2a1be494d3b0c9457e8e81cdcce2a89.

Commit a00ce85af2a1 ("mm: make alloc_demote_folio externally invokable for
migration") was made to let DAMOS_MIGRATE_{HOT,COLD} call the function. 
But a previous commit made DAMOS_MIGRATE_{HOT,COLD} call
alloc_migration_target() instead.  Hence there are no more callers of the
function outside of vmscan.c.  Revert the commit to make the function
static again.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: SeongJae Park <[email protected]>
Reviewed-by: Joshua Hahn <[email protected]>
Cc: David Hildenbrand <[email protected]>
Cc: Honggyu Kim <[email protected]>
Cc: Johannes Weiner <[email protected]>
Cc: Lorenzo Stoakes <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Qi Zheng <[email protected]>
Cc: Shakeel Butt <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

1 files changed, 2 insertions, 1 deletions

diff --git a/mm/vmscan.c b/mm/vmscan.c
index 6bebc91cbf2f..620dce753b64 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -1006,7 +1006,8 @@ static void folio_check_dirty_writeback(struct folio *folio,
 		mapping->a_ops->is_dirty_writeback(folio, dirty, writeback);
 }
 
-struct folio *alloc_demote_folio(struct folio *src, unsigned long private)
+static struct folio *alloc_demote_folio(struct folio *src,
+		unsigned long private)
 {
 	struct folio *dst;
 	nodemask_t *allowed_mask;