Re: [PATCH 3/4] mm, swap: cleanup swap entry allocation parameter

[Nhat Pham]

On Mon, Oct 6, 2025 at 1:08 PM Kairui Song <ryncsn@xxxxxxxxx> wrote:
>
> On Tue, Oct 7, 2025 at 4:03 AM Kairui Song <ryncsn@xxxxxxxxx> wrote:
> >
> > From: Kairui Song <kasong@xxxxxxxxxxx>
> >
> > We no longer need this GFP parameter after commit 8578e0c00dcf ("mm, swap:
> > use the swap table for the swap cache and switch API"). Before that
> > commit the GFP parameter is already almost identical for all callers, so
> > nothing changed by that commit. Swap table just moved the GFP to lower
> > layer and make it more defined and changes depend on atomic or sleep
> > allocation.
> >
> > Now this parameter is no longer used, just remove it. No behavior
> > change.
> >
> > Signed-off-by: Kairui Song <kasong@xxxxxxxxxxx>
> > ---
> >  include/linux/swap.h | 4 ++--
> >  mm/shmem.c           | 2 +-
> >  mm/swapfile.c        | 2 +-
> >  mm/vmscan.c          | 4 ++--
> >  4 files changed, 6 insertions(+), 6 deletions(-)
> >
> > diff --git a/include/linux/swap.h b/include/linux/swap.h
> > index e818fbade1e2..a4b264817735 100644
> > --- a/include/linux/swap.h
> > +++ b/include/linux/swap.h
> > @@ -462,7 +462,7 @@ static inline long get_nr_swap_pages(void)
> >  }
> >
> >  extern void si_swapinfo(struct sysinfo *);
> > -int folio_alloc_swap(struct folio *folio, gfp_t gfp_mask);
> > +int folio_alloc_swap(struct folio *folio);
> >  bool folio_free_swap(struct folio *folio);
> >  void put_swap_folio(struct folio *folio, swp_entry_t entry);
> >  extern swp_entry_t get_swap_page_of_type(int);
> > @@ -560,7 +560,7 @@ static inline int swp_swapcount(swp_entry_t entry)
> >         return 0;
> >  }
> >
> > -static inline int folio_alloc_swap(struct folio *folio, gfp_t gfp_mask)
> > +static inline int folio_alloc_swap(struct folio *folio)
> >  {
> >         return -EINVAL;
> >  }
> > diff --git a/mm/shmem.c b/mm/shmem.c
> > index 45f51745ad88..63092cc0b141 100644
> > --- a/mm/shmem.c
> > +++ b/mm/shmem.c
> > @@ -1617,7 +1617,7 @@ int shmem_writeout(struct folio *folio, struct swap_iocb **plug,
> >                 folio_mark_uptodate(folio);
> >         }
> >
> > -       if (!folio_alloc_swap(folio, __GFP_HIGH | __GFP_NOMEMALLOC | __GFP_NOWARN)) {
> > +       if (!folio_alloc_swap(folio)) {
> >                 bool first_swapped = shmem_recalc_inode(inode, 0, nr_pages);
> >                 int error;
> >
> > diff --git a/mm/swapfile.c b/mm/swapfile.c
> > index 732e07c70ce9..534b21aeef5a 100644
> > --- a/mm/swapfile.c
> > +++ b/mm/swapfile.c
> > @@ -1425,7 +1425,7 @@ static bool swap_sync_discard(void)
> >   * Context: Caller needs to hold the folio lock.
> >   * Return: Whether the folio was added to the swap cache.
> >   */
> > -int folio_alloc_swap(struct folio *folio, gfp_t gfp)
> > +int folio_alloc_swap(struct folio *folio)
> >  {
> >         unsigned int order = folio_order(folio);
> >         unsigned int size = 1 << order;
>
> One trivial issue for myself, I better update the kerneldoc too...
> sorry about this:
>

LGTM, with the kerneldoc update:

Acked-by: Nhat Pham <nphamcs@xxxxxxxxx>