Commit ad27ce20 authored by ZhangPeng's avatar ZhangPeng Committed by Andrew Morton
Browse files

mm/hugetlb: use a folio in copy_hugetlb_page_range() 

Patch series "Convert several functions in hugetlb.c to use a folio", v2.

This patch series converts three functions in hugetlb.c to use a folio,
which can remove several implicit calls to compound_head().


This patch (of 3):

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.

Link: https://lkml.kernel.org/r/20230606062013.2947002-1-zhangpeng362@huawei.com
Link: https://lkml.kernel.org/r/20230606062013.2947002-2-zhangpeng362@huawei.com


Signed-off-by: default avatarZhangPeng <zhangpeng362@huawei.com>
Suggested-by: default avatarMatthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: default avatarMuchun Song <songmuchun@bytedance.com>
Reviewed-by: default avatarSidhartha Kumar <sidhartha.kumar@oracle.com>
Reviewed-by: default avatarMatthew Wilcox (Oracle) <willy@infradead.org>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Nanyong Sun <sunnanyong@huawei.com>
Cc: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 9fc96c7c

mm/hugetlb.c

+11 −11
Original line number Diff line number Diff line
@@ -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),

							    pte_folio,

							    addr, dst_vma);

				put_page(ptepage);

				folio_put(pte_folio);

				if (ret) {

					folio_put(new_folio);

					break;