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: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/mm/vmscan.c b/mm/vmscan.c
index 3ed0acc..2ec5bcb 100644 (file)
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -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;
 }