From 14ddee4126fecff5c5c0a84940ba34f0bfe3e708 Mon Sep 17 00:00:00 2001 From: "Matthew Wilcox (Oracle)" Date: Mon, 16 Jan 2023 19:18:13 +0000 Subject: [PATCH] mm: use a folio in copy_present_pte() We still have to keep the page around because we need to know which page in the folio we're copying, but we can replace five implict calls to compound_head() with one. Link: https://lkml.kernel.org/r/20230116191813.2145215-6-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) Reviewed-by: Zi Yan Signed-off-by: Andrew Morton --- mm/memory.c | 15 +++++++++------ 1 file changed, 9 insertions(+), 6 deletions(-) diff --git a/mm/memory.c b/mm/memory.c index 20a5c8087a5a..029f838587d1 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -906,25 +906,28 @@ copy_present_pte(struct vm_area_struct *dst_vma, struct vm_area_struct *src_vma, unsigned long vm_flags = src_vma->vm_flags; pte_t pte = *src_pte; struct page *page; + struct folio *folio; page = vm_normal_page(src_vma, addr, pte); - if (page && PageAnon(page)) { + if (page) + folio = page_folio(page); + if (page && folio_test_anon(folio)) { /* * If this page may have been pinned by the parent process, * copy the page immediately for the child so that we'll always * guarantee the pinned page won't be randomly replaced in the * future. */ - get_page(page); + folio_get(folio); if (unlikely(page_try_dup_anon_rmap(page, false, src_vma))) { - /* Page maybe pinned, we have to copy. */ - put_page(page); + /* Page may be pinned, we have to copy. */ + folio_put(folio); return copy_present_page(dst_vma, src_vma, dst_pte, src_pte, addr, rss, prealloc, page); } rss[MM_ANONPAGES]++; } else if (page) { - get_page(page); + folio_get(folio); page_dup_file_rmap(page, false); rss[mm_counter_file(page)]++; } @@ -937,7 +940,7 @@ copy_present_pte(struct vm_area_struct *dst_vma, struct vm_area_struct *src_vma, ptep_set_wrprotect(src_mm, addr, src_pte); pte = pte_wrprotect(pte); } - VM_BUG_ON(page && PageAnon(page) && PageAnonExclusive(page)); + VM_BUG_ON(page && folio_test_anon(folio) && PageAnonExclusive(page)); /* * If it's a shared mapping, mark it clean in