[PATCH v2 1/3] mm/hugetlb: Use a folio in copy_hugetlb_page_range()

From: Peng Zhang
Date: Tue Jun 06 2023 - 02:21:23 EST


From: ZhangPeng <zhangpeng362@xxxxxxxxxx>

We can replace five implict calls to compound_head() with one by using
pte_folio. The page we get back is always a head page, so we just
convert ptepage to pte_folio.

Suggested-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
Signed-off-by: ZhangPeng <zhangpeng362@xxxxxxxxxx>
Reviewed-by: Muchun Song <songmuchun@xxxxxxxxxxxxx>
Reviewed-by: Sidhartha Kumar <sidhartha.kumar@xxxxxxxxxx>
---
mm/hugetlb.c | 22 +++++++++++-----------
1 file changed, 11 insertions(+), 11 deletions(-)

diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index ea24718db4af..d6f6d19958a5 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -5016,7 +5016,7 @@ int copy_hugetlb_page_range(struct mm_struct *dst, struct mm_struct *src,
struct vm_area_struct *src_vma)
{
pte_t *src_pte, *dst_pte, entry;
- struct page *ptepage;
+ struct folio *pte_folio;
unsigned long addr;
bool cow = is_cow_mapping(src_vma->vm_flags);
struct hstate *h = hstate_vma(src_vma);
@@ -5115,8 +5115,8 @@ int copy_hugetlb_page_range(struct mm_struct *dst, struct mm_struct *src,
set_huge_pte_at(dst, addr, dst_pte, entry);
} else {
entry = huge_ptep_get(src_pte);
- ptepage = pte_page(entry);
- get_page(ptepage);
+ pte_folio = page_folio(pte_page(entry));
+ folio_get(pte_folio);

/*
* Failing to duplicate the anon rmap is a rare case
@@ -5128,10 +5128,10 @@ int copy_hugetlb_page_range(struct mm_struct *dst, struct mm_struct *src,
* need to be without the pgtable locks since we could
* sleep during the process.
*/
- if (!PageAnon(ptepage)) {
- page_dup_file_rmap(ptepage, true);
- } else if (page_try_dup_anon_rmap(ptepage, true,
- src_vma)) {
+ if (!folio_test_anon(pte_folio)) {
+ page_dup_file_rmap(&pte_folio->page, true);
+ } else if (page_try_dup_anon_rmap(&pte_folio->page,
+ true, src_vma)) {
pte_t src_pte_old = entry;
struct folio *new_folio;

@@ -5140,14 +5140,14 @@ int copy_hugetlb_page_range(struct mm_struct *dst, struct mm_struct *src,
/* Do not use reserve as it's private owned */
new_folio = alloc_hugetlb_folio(dst_vma, addr, 1);
if (IS_ERR(new_folio)) {
- put_page(ptepage);
+ folio_put(pte_folio);
ret = PTR_ERR(new_folio);
break;
}
ret = copy_user_large_folio(new_folio,
- page_folio(ptepage),
- addr, dst_vma);
- put_page(ptepage);
+ pte_folio,
+ addr, dst_vma);
+ folio_put(pte_folio);
if (ret) {
folio_put(new_folio);
break;
--
2.25.1