mm: use a folio in __collapse_huge_page_copy_succeeded()

These pages are all chained together through the lru list, so we know
they're folios.  Use the folio APIs to save three hidden calls to
compound_head().

Link: https://lkml.kernel.org/r/20240227174254.710559-18-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/mm/khugepaged.c b/mm/khugepaged.c
index 1c0073daad828ec0a6e69d13a99d33043cf83e59..b9223e803262e39020d887a7dabe3049fc77db6b 100644 (file)
--- a/mm/khugepaged.c
+++ b/mm/khugepaged.c
@@ -689,9 +689,7 @@ static void __collapse_huge_page_copy_succeeded(pte_t *pte,
                                                spinlock_t *ptl,
                                                struct list_head *compound_pagelist)
 {
-       struct folio *src_folio;
-       struct page *src_page;
-       struct page *tmp;
+       struct folio *src, *tmp;
        pte_t *_pte;
        pte_t pteval;
 
@@ -710,10 +708,11 @@ static void __collapse_huge_page_copy_succeeded(pte_t *pte,
                                ksm_might_unmap_zero_page(vma->vm_mm, pteval);
                        }
                } else {
-                       src_page = pte_page(pteval);
-                       src_folio = page_folio(src_page);
-                       if (!folio_test_large(src_folio))
-                               release_pte_folio(src_folio);
+                       struct page *src_page = pte_page(pteval);
+
+                       src = page_folio(src_page);
+                       if (!folio_test_large(src))
+                               release_pte_folio(src);
                        /*
                         * ptl mostly unnecessary, but preempt has to
                         * be disabled to update the per-cpu stats
@@ -721,20 +720,19 @@ static void __collapse_huge_page_copy_succeeded(pte_t *pte,
                         */
                        spin_lock(ptl);
                        ptep_clear(vma->vm_mm, address, _pte);
-                       folio_remove_rmap_pte(src_folio, src_page, vma);
+                       folio_remove_rmap_pte(src, src_page, vma);
                        spin_unlock(ptl);
                        free_page_and_swap_cache(src_page);
                }
        }
 
-       list_for_each_entry_safe(src_page, tmp, compound_pagelist, lru) {
-               list_del(&src_page->lru);
-               mod_node_page_state(page_pgdat(src_page),
-                                   NR_ISOLATED_ANON + page_is_file_lru(src_page),
-                                   -compound_nr(src_page));
-               unlock_page(src_page);
-               free_swap_cache(src_page);
-               putback_lru_page(src_page);
+       list_for_each_entry_safe(src, tmp, compound_pagelist, lru) {
+               list_del(&src->lru);
+               node_stat_sub_folio(src, NR_ISOLATED_ANON +
+                               folio_is_file_lru(src));
+               folio_unlock(src);
+               free_swap_cache(&src->page);
+               folio_putback_lru(src);
        }
 }