[PATCH 8/9] mm: Convert collapse_huge_page() to use a folio

["Matthew Wilcox (Oracle)" <willy@infradead.org>]

Replace three calls to compound_head() with one.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
---
 mm/khugepaged.c | 15 ++++++++-------
 1 file changed, 8 insertions(+), 7 deletions(-)

diff --git a/mm/khugepaged.c b/mm/khugepaged.c
index e722f754797f..f7ec73976c38 100644
--- a/mm/khugepaged.c
+++ b/mm/khugepaged.c
@@ -1087,6 +1087,7 @@ static int collapse_huge_page(struct mm_struct *mm, unsigned long address,
 	pmd_t *pmd, _pmd;
 	pte_t *pte;
 	pgtable_t pgtable;
+	struct folio *folio;
 	struct page *hpage;
 	spinlock_t *pmd_ptl, *pte_ptl;
 	int result = SCAN_FAIL;
@@ -1209,13 +1210,13 @@ static int collapse_huge_page(struct mm_struct *mm, unsigned long address,
 	if (unlikely(result != SCAN_SUCCEED))
 		goto out_up_write;
 
+	folio = page_folio(hpage);
 	/*
-	 * spin_lock() below is not the equivalent of smp_wmb(), but
-	 * the smp_wmb() inside __SetPageUptodate() can be reused to
-	 * avoid the copy_huge_page writes to become visible after
-	 * the set_pmd_at() write.
+	 * The smp_wmb() inside __folio_mark_uptodate() ensures the
+	 * copy_huge_page writes become visible before the set_pmd_at()
+	 * write.
 	 */
-	__SetPageUptodate(hpage);
+	__folio_mark_uptodate(folio);
 	pgtable = pmd_pgtable(_pmd);
 
 	_pmd = mk_huge_pmd(hpage, vma->vm_page_prot);
@@ -1223,8 +1224,8 @@ static int collapse_huge_page(struct mm_struct *mm, unsigned long address,
 
 	spin_lock(pmd_ptl);
 	BUG_ON(!pmd_none(*pmd));
-	page_add_new_anon_rmap(hpage, vma, address);
-	lru_cache_add_inactive_or_unevictable(hpage, vma);
+	folio_add_new_anon_rmap(folio, vma, address);
+	folio_add_lru_vma(folio, vma);
 	pgtable_trans_huge_deposit(mm, pmd, pgtable);
 	set_pmd_at(mm, address, pmd, _pmd);
 	update_mmu_cache_pmd(vma, address, pmd);
-- 
2.42.0