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>
---
 tools/testing/selftests/mm/vm_util.c | 139 +++++++++++++++++++++++++++
 tools/testing/selftests/mm/vm_util.h |   2 +
 2 files changed, 141 insertions(+)

diff --git a/tools/testing/selftests/mm/vm_util.c b/tools/testing/selftests/mm/vm_util.c
index 9dafa7669ef9..373621145b2a 100644
--- a/tools/testing/selftests/mm/vm_util.c
+++ b/tools/testing/selftests/mm/vm_util.c
@@ -17,6 +17,12 @@
 #define STATUS_FILE_PATH "/proc/self/status"
 #define MAX_LINE_LENGTH 500
 
+#define PGMAP_PRESENT		(1UL << 63)
+#define KPF_COMPOUND_HEAD	(1UL << 15)
+#define KPF_COMPOUND_TAIL	(1UL << 16)
+#define KPF_THP			(1UL << 22)
+#define PFN_MASK     ((1UL<<55)-1)
+
 unsigned int __page_size;
 unsigned int __page_shift;
 
@@ -338,6 +344,139 @@ int detect_hugetlb_page_sizes(size_t sizes[], int max)
 	return count;
 }
 
+static int get_page_flags(uint64_t vpn, int pagemap_file, int kpageflags_file,
+			  uint64_t *flags)
+{
+	uint64_t pfn;
+	size_t count;
+
+	count = pread(pagemap_file, &pfn, sizeof(pfn),
+		      vpn * sizeof(pfn));
+
+	if (count != sizeof(pfn))
+		return -1;
+
+	/*
+	 * Treat non-present page as a page without any flag, so that
+	 * gather_folio_orders() just record the current folio order.
+	 */
+	if (!(pfn & PGMAP_PRESENT)) {
+		*flags = 0;
+		return 0;
+	}
+
+	count = pread(kpageflags_file, flags, sizeof(*flags),
+		      (pfn & PFN_MASK) * sizeof(*flags));
+
+	if (count != sizeof(*flags))
+		return -1;
+
+	return 0;
+}
+
+static int gather_folio_orders(uint64_t vpn_start, size_t nr_pages,
+			       int pagemap_file, int kpageflags_file,
+			       int orders[], int nr_orders)
+{
+	uint64_t page_flags = 0;
+	int cur_order = -1;
+	uint64_t vpn;
+
+	if (!pagemap_file || !kpageflags_file)
+		return -1;
+	if (nr_orders <= 0)
+		return -1;
+
+	for (vpn = vpn_start; vpn < vpn_start + nr_pages; ) {
+		uint64_t next_folio_vpn;
+		int status;
+
+		if (get_page_flags(vpn, pagemap_file, kpageflags_file, &page_flags))
+			return -1;
+
+		/* all order-0 pages with possible false postive (non folio) */
+		if (!(page_flags & (KPF_COMPOUND_HEAD | KPF_COMPOUND_TAIL))) {
+			orders[0]++;
+			vpn++;
+			continue;
+		}
+
+		/* skip non thp compound pages */
+		if (!(page_flags & KPF_THP)) {
+			vpn++;
+			continue;
+		}
+
+		/* vpn points to part of a THP at this point */
+		if (page_flags & KPF_COMPOUND_HEAD)
+			cur_order = 1;
+		else {
+			/* not a head nor a tail in a THP? */
+			if (!(page_flags & KPF_COMPOUND_TAIL))
+				return -1;
+			continue;
+		}
+
+		next_folio_vpn = vpn + (1 << cur_order);
+
+		if (next_folio_vpn >= vpn_start + nr_pages)
+			break;
+
+		while (!(status = get_page_flags(next_folio_vpn, pagemap_file,
+						 kpageflags_file,
+						 &page_flags))) {
+			/* next compound head page or order-0 page */
+			if ((page_flags & KPF_COMPOUND_HEAD) ||
+			    !(page_flags & (KPF_COMPOUND_HEAD |
+			      KPF_COMPOUND_TAIL))) {
+				if (cur_order < nr_orders) {
+					orders[cur_order]++;
+					cur_order = -1;
+					vpn = next_folio_vpn;
+				}
+				break;
+			}
+
+			/* not a head nor a tail in a THP? */
+			if (!(page_flags & KPF_COMPOUND_TAIL))
+				return -1;
+
+			cur_order++;
+			next_folio_vpn = vpn + (1 << cur_order);
+		}
+
+		if (status)
+			return status;
+	}
+	if (cur_order > 0 && cur_order < nr_orders)
+		orders[cur_order]++;
+	return 0;
+}
+
+int check_folio_orders(uint64_t vpn_start, size_t nr_pages, int pagemap_file,
+			int kpageflags_file, int orders[], int nr_orders)
+{
+	int vpn_orders[nr_orders];
+	int status;
+	int i;
+
+	memset(vpn_orders, 0, sizeof(int) * nr_orders);
+	status = gather_folio_orders(vpn_start, nr_pages, pagemap_file,
+				     kpageflags_file, vpn_orders, nr_orders);
+	if (status)
+		return status;
+
+	status = 0;
+	for (i = 0; i < nr_orders; i++)
+		if (vpn_orders[i] != orders[i]) {
+			ksft_print_msg("order %d: expected: %d got %d\n", i,
+				       orders[i], vpn_orders[i]);
+			status = -1;
+		}
+
+	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 b55d1809debc..dee9504a6129 100644
--- a/tools/testing/selftests/mm/vm_util.h
+++ b/tools/testing/selftests/mm/vm_util.h
@@ -85,6 +85,8 @@ 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(uint64_t vpn_start, size_t nr_pages, 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);
-- 
2.47.2

On 2025/8/6 10:20, 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>
> ---
>   tools/testing/selftests/mm/vm_util.c | 139 +++++++++++++++++++++++++++
>   tools/testing/selftests/mm/vm_util.h |   2 +
>   2 files changed, 141 insertions(+)
> 
> diff --git a/tools/testing/selftests/mm/vm_util.c b/tools/testing/selftests/mm/vm_util.c
> index 9dafa7669ef9..373621145b2a 100644
> --- a/tools/testing/selftests/mm/vm_util.c
> +++ b/tools/testing/selftests/mm/vm_util.c
> @@ -17,6 +17,12 @@
>   #define STATUS_FILE_PATH "/proc/self/status"
>   #define MAX_LINE_LENGTH 500
>   
> +#define PGMAP_PRESENT		(1UL << 63)
> +#define KPF_COMPOUND_HEAD	(1UL << 15)
> +#define KPF_COMPOUND_TAIL	(1UL << 16)
> +#define KPF_THP			(1UL << 22)
> +#define PFN_MASK     ((1UL<<55)-1)
> +
>   unsigned int __page_size;
>   unsigned int __page_shift;
>   
> @@ -338,6 +344,139 @@ int detect_hugetlb_page_sizes(size_t sizes[], int max)
>   	return count;
>   }
>   
> +static int get_page_flags(uint64_t vpn, int pagemap_file, int kpageflags_file,
> +			  uint64_t *flags)
> +{
> +	uint64_t pfn;
> +	size_t count;
> +
> +	count = pread(pagemap_file, &pfn, sizeof(pfn),
> +		      vpn * sizeof(pfn));
> +
> +	if (count != sizeof(pfn))
> +		return -1;
> +
> +	/*
> +	 * Treat non-present page as a page without any flag, so that
> +	 * gather_folio_orders() just record the current folio order.
> +	 */
> +	if (!(pfn & PGMAP_PRESENT)) {
> +		*flags = 0;
> +		return 0;
> +	}

It looks like you can reuse the helper pagemap_get_pfn() in this file?

> +
> +	count = pread(kpageflags_file, flags, sizeof(*flags),
> +		      (pfn & PFN_MASK) * sizeof(*flags));
> +
> +	if (count != sizeof(*flags))
> +		return -1;
> +
> +	return 0;
> +}
> +
> +static int gather_folio_orders(uint64_t vpn_start, size_t nr_pages,

In this file, other helper functions use userspace virtual address as 
parameters, so can we consistently use virtual address for calculations 
instead of the 'vpn_start'?

> +			       int pagemap_file, int kpageflags_file,
> +			       int orders[], int nr_orders)
> +{
> +	uint64_t page_flags = 0;
> +	int cur_order = -1;
> +	uint64_t vpn;
> +
> +	if (!pagemap_file || !kpageflags_file)
> +		return -1;
> +	if (nr_orders <= 0)
> +		return -1;
> +
> +	for (vpn = vpn_start; vpn < vpn_start + nr_pages; ) {
> +		uint64_t next_folio_vpn;
> +		int status;
> +
> +		if (get_page_flags(vpn, pagemap_file, kpageflags_file, &page_flags))
> +			return -1;
> +
> +		/* all order-0 pages with possible false postive (non folio) */
> +		if (!(page_flags & (KPF_COMPOUND_HEAD | KPF_COMPOUND_TAIL))) {
> +			orders[0]++;
> +			vpn++;
> +			continue;
> +		}
> +
> +		/* skip non thp compound pages */
> +		if (!(page_flags & KPF_THP)) {
> +			vpn++;
> +			continue;
> +		}
> +
> +		/* vpn points to part of a THP at this point */
> +		if (page_flags & KPF_COMPOUND_HEAD)
> +			cur_order = 1;
> +		else {
> +			/* not a head nor a tail in a THP? */
> +			if (!(page_flags & KPF_COMPOUND_TAIL))
> +				return -1;
> +			continue;
> +		}
> +
> +		next_folio_vpn = vpn + (1 << cur_order);
> +
> +		if (next_folio_vpn >= vpn_start + nr_pages)
> +			break;
> +
> +		while (!(status = get_page_flags(next_folio_vpn, pagemap_file,
> +						 kpageflags_file,
> +						 &page_flags))) {
> +			/* next compound head page or order-0 page */
> +			if ((page_flags & KPF_COMPOUND_HEAD) ||
> +			    !(page_flags & (KPF_COMPOUND_HEAD |
> +			      KPF_COMPOUND_TAIL))) {
> +				if (cur_order < nr_orders) {
> +					orders[cur_order]++;
> +					cur_order = -1;
> +					vpn = next_folio_vpn;
> +				}
> +				break;
> +			}
> +
> +			/* not a head nor a tail in a THP? */
> +			if (!(page_flags & KPF_COMPOUND_TAIL))
> +				return -1;
> +
> +			cur_order++;
> +			next_folio_vpn = vpn + (1 << cur_order);
> +		}
> +
> +		if (status)
> +			return status;
> +	}
> +	if (cur_order > 0 && cur_order < nr_orders)
> +		orders[cur_order]++;
> +	return 0;
> +}
> +
> +int check_folio_orders(uint64_t vpn_start, size_t nr_pages, int pagemap_file,
> +			int kpageflags_file, int orders[], int nr_orders)
> +{
> +	int vpn_orders[nr_orders];

IIRC, we should avoid using VLA (variable length arrays)?

> +	int status;
> +	int i;
> +
> +	memset(vpn_orders, 0, sizeof(int) * nr_orders);
> +	status = gather_folio_orders(vpn_start, nr_pages, pagemap_file,
> +				     kpageflags_file, vpn_orders, nr_orders);
> +	if (status)
> +		return status;
> +
> +	status = 0;
> +	for (i = 0; i < nr_orders; i++)
> +		if (vpn_orders[i] != orders[i]) {
> +			ksft_print_msg("order %d: expected: %d got %d\n", i,
> +				       orders[i], vpn_orders[i]);
> +			status = -1;
> +		}
> +
> +	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 b55d1809debc..dee9504a6129 100644
> --- a/tools/testing/selftests/mm/vm_util.h
> +++ b/tools/testing/selftests/mm/vm_util.h
> @@ -85,6 +85,8 @@ 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(uint64_t vpn_start, size_t nr_pages, 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);

On 7 Aug 2025, at 2:49, Baolin Wang wrote:

> On 2025/8/6 10:20, 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>
>> ---
>>   tools/testing/selftests/mm/vm_util.c | 139 +++++++++++++++++++++++++++
>>   tools/testing/selftests/mm/vm_util.h |   2 +
>>   2 files changed, 141 insertions(+)
>>
>> diff --git a/tools/testing/selftests/mm/vm_util.c b/tools/testing/selftests/mm/vm_util.c
>> index 9dafa7669ef9..373621145b2a 100644
>> --- a/tools/testing/selftests/mm/vm_util.c
>> +++ b/tools/testing/selftests/mm/vm_util.c
>> @@ -17,6 +17,12 @@
>>   #define STATUS_FILE_PATH "/proc/self/status"
>>   #define MAX_LINE_LENGTH 500
>>  +#define PGMAP_PRESENT		(1UL << 63)
>> +#define KPF_COMPOUND_HEAD	(1UL << 15)
>> +#define KPF_COMPOUND_TAIL	(1UL << 16)
>> +#define KPF_THP			(1UL << 22)
>> +#define PFN_MASK     ((1UL<<55)-1)
>> +
>>   unsigned int __page_size;
>>   unsigned int __page_shift;
>>  @@ -338,6 +344,139 @@ int detect_hugetlb_page_sizes(size_t sizes[], int max)
>>   	return count;
>>   }
>>  +static int get_page_flags(uint64_t vpn, int pagemap_file, int kpageflags_file,
>> +			  uint64_t *flags)
>> +{
>> +	uint64_t pfn;
>> +	size_t count;
>> +
>> +	count = pread(pagemap_file, &pfn, sizeof(pfn),
>> +		      vpn * sizeof(pfn));
>> +
>> +	if (count != sizeof(pfn))
>> +		return -1;
>> +
>> +	/*
>> +	 * Treat non-present page as a page without any flag, so that
>> +	 * gather_folio_orders() just record the current folio order.
>> +	 */
>> +	if (!(pfn & PGMAP_PRESENT)) {
>> +		*flags = 0;
>> +		return 0;
>> +	}
>
> It looks like you can reuse the helper pagemap_get_pfn() in this file?

Sure.

>
>> +
>> +	count = pread(kpageflags_file, flags, sizeof(*flags),
>> +		      (pfn & PFN_MASK) * sizeof(*flags));
>> +
>> +	if (count != sizeof(*flags))
>> +		return -1;
>> +
>> +	return 0;
>> +}
>> +
>> +static int gather_folio_orders(uint64_t vpn_start, size_t nr_pages,
>
> In this file, other helper functions use userspace virtual address as parameters, so can we consistently use virtual address for calculations instead of the 'vpn_start'?
>

Sure.

>> +			       int pagemap_file, int kpageflags_file,
>> +			       int orders[], int nr_orders)
>> +{
>> +	uint64_t page_flags = 0;
>> +	int cur_order = -1;
>> +	uint64_t vpn;
>> +
>> +	if (!pagemap_file || !kpageflags_file)
>> +		return -1;
>> +	if (nr_orders <= 0)
>> +		return -1;
>> +
>> +	for (vpn = vpn_start; vpn < vpn_start + nr_pages; ) {
>> +		uint64_t next_folio_vpn;
>> +		int status;
>> +
>> +		if (get_page_flags(vpn, pagemap_file, kpageflags_file, &page_flags))
>> +			return -1;
>> +
>> +		/* all order-0 pages with possible false postive (non folio) */
>> +		if (!(page_flags & (KPF_COMPOUND_HEAD | KPF_COMPOUND_TAIL))) {
>> +			orders[0]++;
>> +			vpn++;
>> +			continue;
>> +		}
>> +
>> +		/* skip non thp compound pages */
>> +		if (!(page_flags & KPF_THP)) {
>> +			vpn++;
>> +			continue;
>> +		}
>> +
>> +		/* vpn points to part of a THP at this point */
>> +		if (page_flags & KPF_COMPOUND_HEAD)
>> +			cur_order = 1;
>> +		else {
>> +			/* not a head nor a tail in a THP? */
>> +			if (!(page_flags & KPF_COMPOUND_TAIL))
>> +				return -1;
>> +			continue;
>> +		}
>> +
>> +		next_folio_vpn = vpn + (1 << cur_order);
>> +
>> +		if (next_folio_vpn >= vpn_start + nr_pages)
>> +			break;
>> +
>> +		while (!(status = get_page_flags(next_folio_vpn, pagemap_file,
>> +						 kpageflags_file,
>> +						 &page_flags))) {
>> +			/* next compound head page or order-0 page */
>> +			if ((page_flags & KPF_COMPOUND_HEAD) ||
>> +			    !(page_flags & (KPF_COMPOUND_HEAD |
>> +			      KPF_COMPOUND_TAIL))) {
>> +				if (cur_order < nr_orders) {
>> +					orders[cur_order]++;
>> +					cur_order = -1;
>> +					vpn = next_folio_vpn;
>> +				}
>> +				break;
>> +			}
>> +
>> +			/* not a head nor a tail in a THP? */
>> +			if (!(page_flags & KPF_COMPOUND_TAIL))
>> +				return -1;
>> +
>> +			cur_order++;
>> +			next_folio_vpn = vpn + (1 << cur_order);
>> +		}
>> +
>> +		if (status)
>> +			return status;
>> +	}
>> +	if (cur_order > 0 && cur_order < nr_orders)
>> +		orders[cur_order]++;
>> +	return 0;
>> +}
>> +
>> +int check_folio_orders(uint64_t vpn_start, size_t nr_pages, int pagemap_file,
>> +			int kpageflags_file, int orders[], int nr_orders)
>> +{
>> +	int vpn_orders[nr_orders];
>
> IIRC, we should avoid using VLA (variable length arrays)?

OK. I can change it to malloc.

Thanks.

>
>> +	int status;
>> +	int i;
>> +
>> +	memset(vpn_orders, 0, sizeof(int) * nr_orders);
>> +	status = gather_folio_orders(vpn_start, nr_pages, pagemap_file,
>> +				     kpageflags_file, vpn_orders, nr_orders);
>> +	if (status)
>> +		return status;
>> +
>> +	status = 0;
>> +	for (i = 0; i < nr_orders; i++)
>> +		if (vpn_orders[i] != orders[i]) {
>> +			ksft_print_msg("order %d: expected: %d got %d\n", i,
>> +				       orders[i], vpn_orders[i]);
>> +			status = -1;
>> +		}
>> +
>> +	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 b55d1809debc..dee9504a6129 100644
>> --- a/tools/testing/selftests/mm/vm_util.h
>> +++ b/tools/testing/selftests/mm/vm_util.h
>> @@ -85,6 +85,8 @@ 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(uint64_t vpn_start, size_t nr_pages, 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);


--
Best Regards,
Yan, Zi

Hi Zi,

Thanks for the patch.

I have a nit suggestion to centralize some of the macro definitions
for better consistency and reusability.

On [Date of patch], Zi Yan wrote:
> diff --git a/tools/testing/selftests/mm/vm_util.c b/tools/testing/selftests/mm/vm_util.c
> ...
> +#define PGMAP_PRESENT		(1UL << 63)
> +#define KPF_COMPOUND_HEAD	(1UL << 15)
> +#define KPF_COMPOUND_TAIL	(1UL << 16)
> +#define KPF_THP			(1UL << 22)
> +#define PFN_MASK		((1UL<<55)-1)

Currently, these macros and `PGMAP_PRESENT` are defined locally in
`vm_util.c`. It would be cleaner to move them to the shared header
`vm_util.h`.

This would also allow us to consistently use `PM_PRESENT` (from the
header) instead of the local `PGMAP_PRESENT` duplicate. I noticed the
patch is already moving in this direction, and we can complete this
cleanup.

How about a change like this?

--- a/tools/testing/selftests/mm/vm_util.c
+++ b/tools/testing/selftests/mm/vm_util.c
@@ -17,17 +17,6 @@
 #define STATUS_FILE_PATH "/proc/self/status"
 #define MAX_LINE_LENGTH 500
 
-#define PGMAP_PRESENT          (1UL << 63)
-#define KPF_COMPOUND_HEAD      (1UL << 15)
-#define KPF_COMPOUND_TAIL      (1UL << 16)
-#define KPF_THP                        (1UL << 22)
-#define PFN_MASK     ((1UL<<55)-1)
-
 unsigned int __page_size;
 unsigned int __page_shift;
 
@@ -360,7 +349,7 @@ static int get_page_flags(uint64_t vpn, int pagemap_file, int kpageflags_file,
 	 * Treat non-present page as a page without any flag, so that
 	 * gather_folio_orders() just record the current folio order.
 	 */
-	if (!(pfn & PGMAP_PRESENT)) {
+	if (!(pfn & PM_PRESENT)) {
 		*flags = 0;
 		return 0;
 	}
--- a/tools/testing/selftests/mm/vm_util.h
+++ b/tools/testing/selftests/mm/vm_util.h
@@ -17,6 +17,11 @@
 #define PM_FILE                        BIT_ULL(61)
 #define PM_SWAP                        BIT_ULL(62)
 #define PM_PRESENT             BIT_ULL(63)
+#define KPF_COMPOUND_HEAD      (1UL << 15)
+#define KPF_COMPOUND_TAIL      (1UL << 16)
+#define KPF_THP                        (1UL << 22)
+#define PFN_MASK     ((1UL<<55)-1)
 
 extern unsigned int __page_size;
 extern unsigned int __page_shift;


Best regards,
wang lian

On 6 Aug 2025, at 23:00, wang lian wrote:

> Hi Zi,
>
> Thanks for the patch.
>
> I have a nit suggestion to centralize some of the macro definitions
> for better consistency and reusability.
>
> On [Date of patch], Zi Yan wrote:
>> diff --git a/tools/testing/selftests/mm/vm_util.c b/tools/testing/selftests/mm/vm_util.c
>> ...
>> +#define PGMAP_PRESENT		(1UL << 63)
>> +#define KPF_COMPOUND_HEAD	(1UL << 15)
>> +#define KPF_COMPOUND_TAIL	(1UL << 16)
>> +#define KPF_THP			(1UL << 22)
>> +#define PFN_MASK		((1UL<<55)-1)
>
> Currently, these macros and `PGMAP_PRESENT` are defined locally in
> `vm_util.c`. It would be cleaner to move them to the shared header
> `vm_util.h`.
>
> This would also allow us to consistently use `PM_PRESENT` (from the
> header) instead of the local `PGMAP_PRESENT` duplicate. I noticed the
> patch is already moving in this direction, and we can complete this
> cleanup.
>
> How about a change like this?

I did not know about PM_PRESENT. Sure, will move the code like you
did below. Thanks.

>
> --- a/tools/testing/selftests/mm/vm_util.c
> +++ b/tools/testing/selftests/mm/vm_util.c
> @@ -17,17 +17,6 @@
>  #define STATUS_FILE_PATH "/proc/self/status"
>  #define MAX_LINE_LENGTH 500
>
> -#define PGMAP_PRESENT          (1UL << 63)
> -#define KPF_COMPOUND_HEAD      (1UL << 15)
> -#define KPF_COMPOUND_TAIL      (1UL << 16)
> -#define KPF_THP                        (1UL << 22)
> -#define PFN_MASK     ((1UL<<55)-1)
> -
>  unsigned int __page_size;
>  unsigned int __page_shift;
>
> @@ -360,7 +349,7 @@ static int get_page_flags(uint64_t vpn, int pagemap_file, int kpageflags_file,
>  	 * Treat non-present page as a page without any flag, so that
>  	 * gather_folio_orders() just record the current folio order.
>  	 */
> -	if (!(pfn & PGMAP_PRESENT)) {
> +	if (!(pfn & PM_PRESENT)) {
>  		*flags = 0;
>  		return 0;
>  	}
> --- a/tools/testing/selftests/mm/vm_util.h
> +++ b/tools/testing/selftests/mm/vm_util.h
> @@ -17,6 +17,11 @@
>  #define PM_FILE                        BIT_ULL(61)
>  #define PM_SWAP                        BIT_ULL(62)
>  #define PM_PRESENT             BIT_ULL(63)
> +#define KPF_COMPOUND_HEAD      (1UL << 15)
> +#define KPF_COMPOUND_TAIL      (1UL << 16)
> +#define KPF_THP                        (1UL << 22)
> +#define PFN_MASK     ((1UL<<55)-1)
>
>  extern unsigned int __page_size;
>  extern unsigned int __page_shift;
>
>
> Best regards,
> wang lian


--
Best Regards,
Yan, Zi