Re: [PATCH 1/2] mm: remove page_rmapping()

[zhangpeng (AS)]

On 2023/7/1 0:03, Sidhartha Kumar wrote:

> On 6/30/23 5:13 AM, Peng Zhang wrote:
> > From: ZhangPeng <zhangpeng362@xxxxxxxxxx>
> >
> > After converting the last user to folio_raw_mapping(), we can safely
> > remove the function.
> >
> > Signed-off-by: ZhangPeng <zhangpeng362@xxxxxxxxxx>
> > ---
> >   include/linux/mm.h | 1 -
> >   mm/memory.c        | 2 +-
> >   mm/util.c          | 6 ------
> >   3 files changed, 1 insertion(+), 8 deletions(-)
> >
> > diff --git a/include/linux/mm.h b/include/linux/mm.h
> > index 9ecb8b9c07f6..8c7eba7370b2 100644
> > --- a/include/linux/mm.h
> > +++ b/include/linux/mm.h
> > @@ -2129,7 +2129,6 @@ static inline void *folio_address(const struct 
> > folio *folio)
> >       return page_address(&folio->page);
> >   }
> >   -extern void *page_rmapping(struct page *page);
> >   extern pgoff_t __page_file_index(struct page *page);
> >     /*
> > diff --git a/mm/memory.c b/mm/memory.c
> > index 21fab2727209..6921df44a99f 100644
> > --- a/mm/memory.c
> > +++ b/mm/memory.c
> > @@ -2979,7 +2979,7 @@ static vm_fault_t 
> > fault_dirty_shared_page(struct vm_fault *vmf)
> >        * pinned by vma->vm_file's reference.  We rely on unlock_page()'s
> >        * release semantics to prevent the compiler from undoing this 
> > copying.
> >        */
>
>
>     struct page *page = vmf->page;
>
>     ...
>
>     dirtied = set_page_dirty(page);
>     VM_BUG_ON_PAGE(PageAnon(page), page);
>
> Can this earlier part of the function be converted to folios so a 
> folio can be passed directly in folio_raw_mapping()?

Thanks for your feedback.

I convert the last user to use a folio in patch 2. I'll reverse the order of the two patches.

Best Regards,
Peng

> > -    mapping = page_rmapping(page);
> > +    mapping = folio_raw_mapping(page_folio(page));
> >       unlock_page(page);
> >         if (!page_mkwrite)
> > diff --git a/mm/util.c b/mm/util.c
> > index dd12b9531ac4..5e9305189c3f 100644
> > --- a/mm/util.c
> > +++ b/mm/util.c
> > @@ -734,12 +734,6 @@ void *vcalloc(size_t n, size_t size)
> >   }
> >   EXPORT_SYMBOL(vcalloc);
> >   -/* Neutral page->mapping pointer to address_space or anon_vma or 
> > other */
> > -void *page_rmapping(struct page *page)
> > -{
> > -    return folio_raw_mapping(page_folio(page));
> > -}
> > -
> >   struct anon_vma *folio_anon_vma(struct folio *folio)
> >   {
> >       unsigned long mapping = (unsigned long)folio->mapping;