Re: [PATCH v4 09/16] slab: Remove folio references from __do_krealloc()

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

On Thu, Nov 13, 2025 at 12:09:23AM +0000, Matthew Wilcox (Oracle) wrote:
> One slight tweak I made is to calculate 'ks' earlier, which means we
> can reuse it in the warning rather than calculating the object size twice.
> 
> Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
> ---

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

>  mm/slub.c | 14 +++++++-------
>  1 file changed, 7 insertions(+), 7 deletions(-)
> 
> diff --git a/mm/slub.c b/mm/slub.c
> index 184bab91e0af..4570d1dce271 100644
> --- a/mm/slub.c
> +++ b/mm/slub.c
> @@ -6977,16 +6977,16 @@ __do_krealloc(const void *p, size_t new_size, unsigned long align, gfp_t flags,
>  	if (is_kfence_address(p)) {
>  		ks = orig_size = kfence_ksize(p);
>  	} else {
> -		struct folio *folio;
> +		struct page *page = virt_to_page(p);
> +		struct slab *slab = page_slab(page);
>  
> -		folio = virt_to_folio(p);
> -		if (unlikely(!folio_test_slab(folio))) {
> +		if (!slab) {

nit: unlikely() is gone.

>  			/* Big kmalloc object */
> -			WARN_ON(folio_size(folio) <= KMALLOC_MAX_CACHE_SIZE);
> -			WARN_ON(p != folio_address(folio));
> -			ks = folio_size(folio);
> +			ks = page_size(page);
> +			WARN_ON(ks <= KMALLOC_MAX_CACHE_SIZE);
> +			WARN_ON(p != page_address(page));
>  		} else {
> -			s = folio_slab(folio)->slab_cache;
> +			s = slab->slab_cache;
>  			orig_size = get_orig_size(s, (void *)p);
>  			ks = s->object_size;
>  		}
> -- 
> 2.47.2

-- 
Cheers,
Harry / Hyeonggon