[PATCH v2 03/10] mm: huge_memory: use a folio in __split_huge_pmd_locked()

Kefeng Wang
2023-11-04T03:55:50Z

Use a folio in __split_huge_pmd_locked() which replaces five
compound_head() call with two page_folio() calls.

Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
---
mm/huge_memory.c | 19 ++++++++++---------
1 file changed, 10 insertions(+), 9 deletions(-)

diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index f31f02472396..34dd01970927 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -2117,6 +2117,7 @@ static void __split_huge_pmd_locked(struct vm_area_struct *vma, pmd_t *pmd,
count_vm_event(THP_SPLIT_PMD);

if (!vma_is_anonymous(vma)) {
+ struct folio *folio;
old_pmd = pmdp_huge_clear_flush(vma, haddr, pmd);
/*
* We are going to unmap this huge page. So
@@ -2130,17 +2131,17 @@ static void __split_huge_pmd_locked(struct vm_area_struct *vma, pmd_t *pmd,
swp_entry_t entry;

entry = pmd_to_swp_entry(old_pmd);
- page = pfn_swap_entry_to_page(entry);
+ folio = pfn_swap_entry_to_folio(entry);
} else {
- page = pmd_page(old_pmd);
- if (!PageDirty(page) && pmd_dirty(old_pmd))
- set_page_dirty(page);
- if (!PageReferenced(page) && pmd_young(old_pmd))
- SetPageReferenced(page);
- page_remove_rmap(page, vma, true);
- put_page(page);
+ folio = page_folio(pmd_page(old_pmd));
+ if (!folio_test_dirty(folio) && pmd_dirty(old_pmd))
+ folio_set_dirty(folio);
+ if (!folio_test_referenced(folio) && pmd_young(old_pmd))
+ folio_set_referenced(folio);
+ page_remove_rmap(&folio->page, vma, true);
+ folio_put(folio);
}
- add_mm_counter(mm, mm_counter_file(page), -HPAGE_PMD_NR);
+ add_mm_counter(mm, mm_counter_file(&folio->page), -HPAGE_PMD_NR);
return;
}

--
2.27.0