Re: [PATCH v2 2/3] selftests/mm: add check_folio_orders() helper.

[Baolin Wang <baolin.wang@linux.alibaba.com>]

On 2025/8/9 03:01, Zi Yan wrote:
> The helper gathers an folio order statistics of folios within a virtual
> address range and checks it against a given order list. It aims to provide
> a more precise folio order check instead of just checking the existence of
> PMD folios.
> 
> Signed-off-by: Zi Yan <ziy@nvidia.com>
> ---
>   .../selftests/mm/split_huge_page_test.c       |   4 +-
>   tools/testing/selftests/mm/vm_util.c          | 133 ++++++++++++++++++
>   tools/testing/selftests/mm/vm_util.h          |   7 +
>   3 files changed, 141 insertions(+), 3 deletions(-)
> 

[snip]

> +
> +int check_folio_orders(char *vaddr_start, size_t len, int pagemap_file,
> +			int kpageflags_file, int orders[], int nr_orders)
> +{
> +	int *vaddr_orders;
> +	int status;
> +	int i;
> +
> +	vaddr_orders = (int *)malloc(sizeof(int) * nr_orders);
> +
> +	if (!vaddr_orders)
> +		ksft_exit_fail_msg("Cannot allocate memory for vaddr_orders");
> +
> +	memset(vaddr_orders, 0, sizeof(int) * nr_orders);
> +	status = gather_folio_orders(vaddr_start, len, pagemap_file,
> +				     kpageflags_file, vaddr_orders, nr_orders);
> +	if (status)

Missed calling free(vaddr_orders) before returning.

> +		return status;
> +
> +	status = 0;
> +	for (i = 0; i < nr_orders; i++)
> +		if (vaddr_orders[i] != orders[i]) {
> +			ksft_print_msg("order %d: expected: %d got %d\n", i,
> +				       orders[i], vaddr_orders[i]);
> +			status = -1;
> +		}
> +

Ditto.

> +	return status;
> +}
> +
>   /* If `ioctls' non-NULL, the allowed ioctls will be returned into the var */
>   int uffd_register_with_ioctls(int uffd, void *addr, uint64_t len,
>   			      bool miss, bool wp, bool minor, uint64_t *ioctls)
> diff --git a/tools/testing/selftests/mm/vm_util.h b/tools/testing/selftests/mm/vm_util.h
> index 1843ad48d32b..02e3f1e7065b 100644
> --- a/tools/testing/selftests/mm/vm_util.h
> +++ b/tools/testing/selftests/mm/vm_util.h
> @@ -18,6 +18,11 @@
>   #define PM_SWAP                       BIT_ULL(62)
>   #define PM_PRESENT                    BIT_ULL(63)
>   
> +#define KPF_COMPOUND_HEAD             BIT_ULL(15)
> +#define KPF_COMPOUND_TAIL             BIT_ULL(16)
> +#define KPF_THP                       BIT_ULL(22)
> +
> +
>   /*
>    * Ignore the checkpatch warning, we must read from x but don't want to do
>    * anything with it in order to trigger a read page fault. We therefore must use
> @@ -85,6 +90,8 @@ bool check_huge_shmem(void *addr, int nr_hpages, uint64_t hpage_size);
>   int64_t allocate_transhuge(void *ptr, int pagemap_fd);
>   unsigned long default_huge_page_size(void);
>   int detect_hugetlb_page_sizes(size_t sizes[], int max);
> +int check_folio_orders(char *vaddr_start, size_t len, int pagemap_file,
> +			int kpageflags_file, int orders[], int nr_orders);
>   
>   int uffd_register(int uffd, void *addr, uint64_t len,
>   		  bool miss, bool wp, bool minor);