Re: [PATCH 2/2] mm: use a folio in fault_dirty_shared_page()

Sidhartha Kumar
2023-06-30T15:59:23Z

On 6/30/23 5:13 AM, Peng Zhang wrote:
> From: ZhangPeng <zhangpeng362@huawei.com>
>
> We can replace four implicit calls to compound_head() with one by using
> folio.
>
> Signed-off-by: ZhangPeng <zhangpeng362@huawei.com>
> ---
> mm/memory.c | 10 +++++-----
> 1 file changed, 5 insertions(+), 5 deletions(-)
>
> diff --git a/mm/memory.c b/mm/memory.c
> index 6921df44a99f..73b03706451c 100644
> --- a/mm/memory.c
> +++ b/mm/memory.c
> @@ -2967,20 +2967,20 @@ static vm_fault_t fault_dirty_shared_page(struct vm_fault *vmf)
> {
> struct vm_area_struct *vma = vmf->vma;
> struct address_space *mapping;
> - struct page *page = vmf->page;
> + struct folio *folio = page_folio(vmf->page);
> bool dirtied;
> bool page_mkwrite = vma->vm_ops && vma->vm_ops->page_mkwrite;
>
> - dirtied = set_page_dirty(page);
> - VM_BUG_ON_PAGE(PageAnon(page), page);
> + dirtied = folio_mark_dirty(folio);
> + VM_BUG_ON_FOLIO(folio_test_anon(folio), folio);
> /*
> * Take a local copy of the address_space - page.mapping may be zeroed
> * by truncate after unlock_page(). The address_space itself remains
> * pinned by vma->vm_file's reference. We rely on unlock_page()'s
> * release semantics to prevent the compiler from undoing this copying.
> */
> - mapping = folio_raw_mapping(page_folio(page));
> - unlock_page(page);
> + mapping = folio_raw_mapping(folio);
> + folio_unlock(folio);
>
> if (!page_mkwrite)
> file_update_time(vma->vm_file);
Reviewed-by: Sidhartha Kumar <sidhartha.kumar@oracle.com>