Re: [PATCH 1/4] mm: debug_vm_pgtable: add debug_vm_pgtable_free_huge_page()

[Kefeng Wang <wangkefeng.wang@huawei.com>]

On 2025/9/11 14:56, Kefeng Wang wrote:
> Add a new helper to free huge page to be consistency to
> debug_vm_pgtable_alloc_huge_page(), also move the
> free_contig_range() under CONFIG_ALLOC_CONTIG since all
> caller are built with CONFIG_ALLOC_CONTIG.
> 
> Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
> ---
>   include/linux/gfp.h   |  2 +-
>   mm/debug_vm_pgtable.c | 35 ++++++++++++++++-------------------
>   mm/page_alloc.c       |  2 +-
>   3 files changed, 18 insertions(+), 21 deletions(-)
> 
> diff --git a/include/linux/gfp.h b/include/linux/gfp.h
> index 5ebf26fcdcfa..651acd42256f 100644
> --- a/include/linux/gfp.h
> +++ b/include/linux/gfp.h
> @@ -437,8 +437,8 @@ extern struct page *alloc_contig_pages_noprof(unsigned long nr_pages, gfp_t gfp_
>   					      int nid, nodemask_t *nodemask);
>   #define alloc_contig_pages(...)			alloc_hooks(alloc_contig_pages_noprof(__VA_ARGS__))
>   
> -#endif
>   void free_contig_range(unsigned long pfn, unsigned long nr_pages);
> +#endif
>   
>   #ifdef CONFIG_CONTIG_ALLOC
>   static inline struct folio *folio_alloc_gigantic_noprof(int order, gfp_t gfp,
> diff --git a/mm/debug_vm_pgtable.c b/mm/debug_vm_pgtable.c
> index 830107b6dd08..767321a8b26c 100644
> --- a/mm/debug_vm_pgtable.c
> +++ b/mm/debug_vm_pgtable.c
> @@ -946,22 +946,26 @@ static unsigned long __init get_random_vaddr(void)
>   	return random_vaddr;
>   }
>   
> -static void __init destroy_args(struct pgtable_debug_args *args)
> +static void __init
> +debug_vm_pgtable_free_huge_page(struct pgtable_debug_args *args,
> +		unsigned long pfn, int order)
>   {
> -	struct page *page = NULL;
> +#ifdef CONFIG_CONTIG_ALLOC
> +	if (args->is_contiguous_page) {
> +		free_contig_range(pfn, 1 << order);
> +		return;
> +	}
> +#endif
> +	__free_pages(pfn_to_page(pfn), order);
> +}
>   
> +static void __init destroy_args(struct pgtable_debug_args *args)
> +{
>   	/* Free (huge) page */
>   	if (IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE) &&
>   	    has_transparent_pud_hugepage() &&
>   	    args->pud_pfn != ULONG_MAX) {
> -		if (args->is_contiguous_page) {
> -			free_contig_range(args->pud_pfn,
> -					  (1 << (HPAGE_PUD_SHIFT - PAGE_SHIFT)));
> -		} else {
> -			page = pfn_to_page(args->pud_pfn);
> -			__free_pages(page, HPAGE_PUD_SHIFT - PAGE_SHIFT);
> -		}
> -
> +		debug_vm_pgtable_free_huge_page(args, args->pud_pfn, HPAGE_PMD_ORDER);

Should be HPAGE_PUD_ORDER, will fix it.