Re: [PATCH] mm/slub: Use folio_nr_pages() in __free_slab()

[Pedro Falcato <pfalcato@suse.de>]

On Tue, Sep 09, 2025 at 04:59:37PM +0800, Ye Liu wrote:
> 
> 在 2025/9/9 16:46, Dev Jain 写道:
> >
> > On 09/09/25 1:18 pm, Hu Song wrote:
> >> Use folio_nr_pages() helper instead of manual calculation (1 << order)
> >> for better code readability and maintainability.
> >>
> >> Signed-off-by: Hu Song <husong@kylinos.cn>
> >> ---
> >>   mm/slub.c | 2 +-
> >>   1 file changed, 1 insertion(+), 1 deletion(-)
> >>
> >> diff --git a/mm/slub.c b/mm/slub.c
> >> index d257141896c9..eba25461641a 100644
> >> --- a/mm/slub.c
> >> +++ b/mm/slub.c
> >> @@ -2719,7 +2719,7 @@ static void __free_slab(struct kmem_cache *s, struct slab *slab)
> >>   {
> >>       struct folio *folio = slab_folio(slab);
> >>       int order = folio_order(folio);
> >> -    int pages = 1 << order;
> >> +    int pages = folio_nr_pages(folio);
> >>         __slab_clear_pfmemalloc(slab);
> >>       folio->mapping = NULL;
> >
> > I don't know, the current version is more readable to me. We literally
> > compute the order before, so we do a simple 1 << order. I'll leave it
> > to the rest.
> >
> >
> Is the reason for calculating 'order' first because it's needed later.

Yes, we use it 6 lines down.

-- 
Pedro