Re: [PATCH v4 08/16] slab: Remove folio references from kfree()

[Harry Yoo <harry.yoo@oracle.com>]

On Thu, Nov 13, 2025 at 12:09:22AM +0000, Matthew Wilcox (Oracle) wrote:
> This should generate identical code to the previous version, but
> without any dependency on how folios work.
> 
> Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
> ---

Looks good to me,
Reviewed-by: Harry Yoo <harry.yoo@oracle.com>

with a nit below.

>  mm/slub.c | 10 +++++-----
>  1 file changed, 5 insertions(+), 5 deletions(-)
> 
> diff --git a/mm/slub.c b/mm/slub.c
> index 976e116580a6..184bab91e0af 100644
> --- a/mm/slub.c
> +++ b/mm/slub.c
> @@ -6866,7 +6866,7 @@ void kvfree_rcu_cb(struct rcu_head *head)
>   */
>  void kfree(const void *object)
>  {
> -	struct folio *folio;
> +	struct page *page;
>  	struct slab *slab;
>  	struct kmem_cache *s;
>  	void *x = (void *)object;
> @@ -6876,13 +6876,13 @@ void kfree(const void *object)
>  	if (unlikely(ZERO_OR_NULL_PTR(object)))
>  		return;
>  
> -	folio = virt_to_folio(object);
> -	if (unlikely(!folio_test_slab(folio))) {
> -		free_large_kmalloc(&folio->page, (void *)object);
> +	page = virt_to_page(object);
> +	slab = page_slab(page);
> +	if (!slab) {

nit: is it intentional to remove unlikely() hint?

> +		free_large_kmalloc(page, (void *)object);
>  		return;
>  	}
>  
> -	slab = folio_slab(folio);
>  	s = slab->slab_cache;
>  	slab_free(s, slab, x, _RET_IP_);
>  }
> -- 
> 2.47.2

-- 
Cheers,
Harry / Hyeonggon