[PATCH 4/5] mm: khugepaged: pass a folio for set_huge_pmd()

[Kefeng Wang <wangkefeng.wang@xxxxxxxxxx>]

Save one compound_head() and remove last PageTransHuge() in set_huge_pmd().

Signed-off-by: Kefeng Wang <wangkefeng.wang@xxxxxxxxxx>
---
 mm/khugepaged.c | 10 ++++------
 1 file changed, 4 insertions(+), 6 deletions(-)

diff --git a/mm/khugepaged.c b/mm/khugepaged.c
index 02e1463e1a79..ae796219f8a0 100644
--- a/mm/khugepaged.c
+++ b/mm/khugepaged.c
@@ -1455,7 +1455,7 @@ static void collect_mm_slot(struct khugepaged_mm_slot *mm_slot)
 #ifdef CONFIG_SHMEM
 /* hpage must be locked, and mmap_lock must be held */
 static int set_huge_pmd(struct vm_area_struct *vma, unsigned long addr,
-			pmd_t *pmdp, struct page *hpage)
+			pmd_t *pmdp, struct folio *folio)
 {
 	struct vm_fault vmf = {
 		.vma = vma,
@@ -1464,13 +1464,12 @@ static int set_huge_pmd(struct vm_area_struct *vma, unsigned long addr,
 		.pmd = pmdp,
 	};
 
-	VM_BUG_ON(!PageTransHuge(hpage));
 	mmap_assert_locked(vma->vm_mm);
 
-	if (do_set_pmd(&vmf, hpage))
+	if (do_set_pmd(&vmf, &folio->page))
 		return SCAN_FAIL;
 
-	get_page(hpage);
+	folio_get(folio);
 	return SCAN_SUCCEED;
 }
 
@@ -1670,8 +1669,7 @@ int collapse_pte_mapped_thp(struct mm_struct *mm, unsigned long addr,
 maybe_install_pmd:
 	/* step 5: install pmd entry */
 	result = install_pmd
-			? set_huge_pmd(vma, haddr, pmd, &folio->page)
-			: SCAN_SUCCEED;
+			? set_huge_pmd(vma, haddr, pmd, folio) : SCAN_SUCCEED;
 	goto drop_folio;
 abort:
 	if (nr_ptes) {
-- 
2.27.0