Re: [PATCH 1/4] mm/memory: convert do_page_mkwrite() to use folios

zhangpeng (AS)
2023-07-03T09:29:25Z

On 2023/7/3 13:58, Sidhartha Kumar wrote:

> Saves one implicit call to compound_head();
>
> Signed-off-by: Sidhartha Kumar <sidhartha.kumar@oracle.com>
> ---
> mm/memory.c | 10 +++++-----
> 1 file changed, 5 insertions(+), 5 deletions(-)
>
> diff --git a/mm/memory.c b/mm/memory.c
> index 21fab27272092..098fac2f5efc0 100644
> --- a/mm/memory.c
> +++ b/mm/memory.c
> @@ -2932,7 +2932,7 @@ static gfp_t __get_fault_gfp_mask(struct vm_area_struct *vma)
> static vm_fault_t do_page_mkwrite(struct vm_fault *vmf)
> {
> vm_fault_t ret;
> - struct page *page = vmf->page;
> + struct folio *folio = page_folio(vmf->page);
> unsigned int old_flags = vmf->flags;
>
> vmf->flags = FAULT_FLAG_WRITE|FAULT_FLAG_MKWRITE;
> @@ -2947,14 +2947,14 @@ static vm_fault_t do_page_mkwrite(struct vm_fault *vmf)
> if (unlikely(ret & (VM_FAULT_ERROR | VM_FAULT_NOPAGE)))
> return ret;
> if (unlikely(!(ret & VM_FAULT_LOCKED))) {
> - lock_page(page);
> - if (!page->mapping) {
> - unlock_page(page);
> + folio_lock(folio);
> + if (!folio_mapping(folio)) {

Could page->mapping be directly converted to folio->mapping?

Thanks,
Peng

> + folio_unlock(folio);
> return 0; /* retry */
> }
> ret |= VM_FAULT_LOCKED;
> } else
> - VM_BUG_ON_PAGE(!PageLocked(page), page);
> + VM_BUG_ON_FOLIO(!folio_test_locked(folio), folio);
> return ret;
> }
>