Commit ff00a170 authored by Matthew Wilcox (Oracle)'s avatar Matthew Wilcox (Oracle) Committed by Andrew Morton
Browse files

mm/vmscan: convert move_pages_to_lru() to use a folio 

Remove a few hidden calls to compound_head, saving 387 bytes of text on
my test configuration.

Link: https://lkml.kernel.org/r/20220617154248.700416-4-willy@infradead.org


Signed-off-by: default avatarMatthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 166e3d32

mm/vmscan.c

+27 −27
Original line number Diff line number Diff line
@@ -2308,8 +2308,8 @@ static int too_many_isolated(struct pglist_data *pgdat, int file, 
}



/*

 * move_pages_to_lru() moves pages from private @list to appropriate LRU list.

 * On return, @list is reused as a list of pages to be freed by the caller.

 * move_pages_to_lru() moves folios from private @list to appropriate LRU list.

 * On return, @list is reused as a list of folios to be freed by the caller.

 *

 * Returns the number of pages moved to the given lruvec.

 */
@@ -2317,42 +2317,42 @@ static unsigned int move_pages_to_lru(struct lruvec *lruvec, 
				      struct list_head *list)

{

	int nr_pages, nr_moved = 0;

	LIST_HEAD(pages_to_free);

	struct page *page;

	LIST_HEAD(folios_to_free);



	while (!list_empty(list)) {

		page = lru_to_page(list);

		VM_BUG_ON_PAGE(PageLRU(page), page);

		list_del(&page->lru);

		if (unlikely(!page_evictable(page))) {

		struct folio *folio = lru_to_folio(list);



		VM_BUG_ON_FOLIO(folio_test_lru(folio), folio);

		list_del(&folio->lru);

		if (unlikely(!folio_evictable(folio))) {

			spin_unlock_irq(&lruvec->lru_lock);

			putback_lru_page(page);

			folio_putback_lru(folio);

			spin_lock_irq(&lruvec->lru_lock);

			continue;

		}



		/*

		 * The SetPageLRU needs to be kept here for list integrity.

		 * The folio_set_lru needs to be kept here for list integrity.

		 * Otherwise:

		 *   #0 move_pages_to_lru             #1 release_pages

		 *   if !put_page_testzero

		 *				      if (put_page_testzero())

		 *				        !PageLRU //skip lru_lock

		 *     SetPageLRU()

		 *     list_add(&page->lru,)

		 *                                        list_add(&page->lru,)

		 *   if (!folio_put_testzero())

		 *				      if (folio_put_testzero())

		 *				        !lru //skip lru_lock

		 *     folio_set_lru()

		 *     list_add(&folio->lru,)

		 *                                        list_add(&folio->lru,)

		 */

		SetPageLRU(page);

		folio_set_lru(folio);



		if (unlikely(put_page_testzero(page))) {

			__clear_page_lru_flags(page);

		if (unlikely(folio_put_testzero(folio))) {

			__folio_clear_lru_flags(folio);



			if (unlikely(PageCompound(page))) {

			if (unlikely(folio_test_large(folio))) {

				spin_unlock_irq(&lruvec->lru_lock);

				destroy_compound_page(page);

				destroy_compound_page(&folio->page);

				spin_lock_irq(&lruvec->lru_lock);

			} else

				list_add(&page->lru, &pages_to_free);

				list_add(&folio->lru, &folios_to_free);



			continue;

		}
@@ -2361,18 +2361,18 @@ static unsigned int move_pages_to_lru(struct lruvec *lruvec, 
		 * All pages were isolated from the same lruvec (and isolation

		 * inhibits memcg migration).

		 */

		VM_BUG_ON_PAGE(!folio_matches_lruvec(page_folio(page), lruvec), page);

		add_page_to_lru_list(page, lruvec);

		nr_pages = thp_nr_pages(page);

		VM_BUG_ON_FOLIO(!folio_matches_lruvec(folio, lruvec), folio);

		lruvec_add_folio(lruvec, folio);

		nr_pages = folio_nr_pages(folio);

		nr_moved += nr_pages;

		if (PageActive(page))

		if (folio_test_active(folio))

			workingset_age_nonresident(lruvec, nr_pages);

	}



	/*

	 * To save our caller's stack, now use input list for pages to free.

	 */

	list_splice(&pages_to_free, list);

	list_splice(&folios_to_free, list);



	return nr_moved;

}