Commit 1b00ab48 authored by Matthew Wilcox (Oracle)'s avatar Matthew Wilcox (Oracle) Committed by Andrew Morton
Browse files

ksm: use a folio inside cmp_and_merge_page() 

This removes the last call to page_stable_node(), so delete the wrapper. 
It also removes a call to trylock_page() and saves a call to
compound_head(), as well as removing a reference to folio->page.

Link: https://lkml.kernel.org/r/20250916181219.2400258-1-willy@infradead.org


Signed-off-by: default avatarMatthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: default avatarChengming Zhou <chengming.zhou@linux.dev>
Acked-by: default avatarDavid Hildenbrand <david@redhat.com>
Cc: Longlong Xia <xialonglong@kylinos.cn>
Cc: xu xin <xu.xin16@zte.com.cn>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 19c5fb83

mm/ksm.c

+6 −9
Original line number Diff line number Diff line
@@ -1061,11 +1061,6 @@ struct ksm_stable_node *folio_stable_node(const struct folio *folio) 
	return folio_test_ksm(folio) ? folio_raw_mapping(folio) : NULL;

}



static inline struct ksm_stable_node *page_stable_node(struct page *page)

{

	return folio_stable_node(page_folio(page));

}



static inline void folio_set_stable_node(struct folio *folio,

					 struct ksm_stable_node *stable_node)

{
@@ -2225,6 +2220,7 @@ static void stable_tree_append(struct ksm_rmap_item *rmap_item, 
 */

static void cmp_and_merge_page(struct page *page, struct ksm_rmap_item *rmap_item)

{

	struct folio *folio = page_folio(page);

	struct ksm_rmap_item *tree_rmap_item;

	struct page *tree_page = NULL;

	struct ksm_stable_node *stable_node;
@@ -2233,7 +2229,7 @@ static void cmp_and_merge_page(struct page *page, struct ksm_rmap_item *rmap_ite 
	int err;

	bool max_page_sharing_bypass = false;



	stable_node = page_stable_node(page);

	stable_node = folio_stable_node(folio);

	if (stable_node) {

		if (stable_node->head != &migrate_nodes &&

		    get_kpfn_nid(READ_ONCE(stable_node->kpfn)) !=
@@ -2272,7 +2268,7 @@ static void cmp_and_merge_page(struct page *page, struct ksm_rmap_item *rmap_ite 


	/* Start by searching for the folio in the stable tree */

	kfolio = stable_tree_search(page);

	if (&kfolio->page == page && rmap_item->head == stable_node) {

	if (kfolio == folio && rmap_item->head == stable_node) {

		folio_put(kfolio);

		return;

	}
@@ -2353,10 +2349,11 @@ static void cmp_and_merge_page(struct page *page, struct ksm_rmap_item *rmap_ite 
			 * the page is locked, it is better to skip it and

			 * perhaps try again later.

			 */

			if (!trylock_page(page))

			if (!folio_trylock(folio))

				return;

			split_huge_page(page);

			unlock_page(page);

			folio = page_folio(page);

			folio_unlock(folio);

		}

	}

}