mm/ksm: use folio in remove_rmap_item_from_tree

To save 2 compound_head calls.

Link: https://lkml.kernel.org/r/20240411061713.1847574-3-alexs@kernel.orgSigned-off-by: Alex Shi (tencent) <alexs@kernel.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Izik Eidus <izik.eidus@ravellosystems.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Chris Wright <chrisw@sous-sol.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

mm/ksm.c

@@ -1006,16 +1006,16 @@ static void remove_rmap_item_from_tree(struct ksm_rmap_item *rmap_item)
 {
 	if (rmap_item->address & STABLE_FLAG) {
 		struct ksm_stable_node *stable_node;
-		struct page *page;
+		struct folio *folio;
 
 		stable_node = rmap_item->head;
-		page = get_ksm_page(stable_node, GET_KSM_PAGE_LOCK);
-		if (!page)
+		folio = ksm_get_folio(stable_node, GET_KSM_PAGE_LOCK);
+		if (!folio)
 			goto out;
 
 		hlist_del(&rmap_item->hlist);
-		unlock_page(page);
-		put_page(page);
+		folio_unlock(folio);
+		folio_put(folio);
 
 		if (!hlist_empty(&stable_node->hlist))
 			ksm_pages_sharing--;