Re: [PATCH v3 26/54] selftests/mm: hugepage_settings: rename get_free_hugepages()

[Sarthak Sharma <sarthak.sharma@arm.com>]

On 4/29/26 2:12 AM, Mike Rapoport wrote:
> From: "Mike Rapoport (Microsoft)" <rppt@kernel.org>
> 
> ... to hugetlb_free_default_hugepages() for consistency with
> hugetlb_nr_default_pages().
> 
> Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>

Small nit, the commit message says hugetlb_free_default_hugepages() but
the actual function added is hugetlb_free_default_pages().

This change looks good to me. All modified tests produce the same output
as before the patch.

Tested-by: Sarthak Sharma <sarthak.sharma@arm.com>

> ---
>  .../testing/selftests/mm/hugepage_settings.c  | 28 ++++++-------------
>  .../testing/selftests/mm/hugepage_settings.h  | 12 +++++++-
>  tools/testing/selftests/mm/hugetlb-madvise.c  |  4 +--
>  tools/testing/selftests/mm/hugetlb_dio.c      |  6 ++--
>  .../selftests/mm/hugetlb_fault_after_madv.c   |  2 +-
>  .../selftests/mm/hugetlb_madv_vs_map.c        |  2 +-
>  tools/testing/selftests/mm/uffd-stress.c      |  2 +-
>  7 files changed, 28 insertions(+), 28 deletions(-)
> 
> diff --git a/tools/testing/selftests/mm/hugepage_settings.c b/tools/testing/selftests/mm/hugepage_settings.c
> index 5961229b9931..4ae7332b5e1b 100644
> --- a/tools/testing/selftests/mm/hugepage_settings.c
> +++ b/tools/testing/selftests/mm/hugepage_settings.c
> @@ -446,25 +446,6 @@ unsigned long default_huge_page_size(void)
>  	return hps;
>  }
>  
> -unsigned long get_free_hugepages(void)
> -{
> -	unsigned long fhp = 0;
> -	char *line = NULL;
> -	size_t linelen = 0;
> -	FILE *f = fopen("/proc/meminfo", "r");
> -
> -	if (!f)
> -		return fhp;
> -	while (getline(&line, &linelen, f) > 0) {
> -		if (sscanf(line, "HugePages_Free:      %lu", &fhp) == 1)
> -			break;
> -	}
> -
> -	free(line);
> -	fclose(f);
> -	return fhp;
> -}
> -
>  static void hugetlb_sysfs_path(char *buf, size_t buflen,
>  			       unsigned long size, const char *attr)
>  {
> @@ -489,3 +470,12 @@ void hugetlb_set_nr_pages(unsigned long size, unsigned long nr)
>  
>  	write_num(path, nr);
>  }
> +
> +unsigned long hugetlb_free_pages(unsigned long size)
> +{
> +	char path[PATH_MAX];
> +
> +	hugetlb_sysfs_path(path, sizeof(path), size, "free_hugepages");
> +
> +	return read_num(path);
> +}
> diff --git a/tools/testing/selftests/mm/hugepage_settings.h b/tools/testing/selftests/mm/hugepage_settings.h
> index d6f41a45e8ee..57fbf2f57e13 100644
> --- a/tools/testing/selftests/mm/hugepage_settings.h
> +++ b/tools/testing/selftests/mm/hugepage_settings.h
> @@ -92,10 +92,10 @@ bool thp_is_enabled(void);
>  
>  int detect_hugetlb_page_sizes(unsigned long sizes[], int max);
>  unsigned long default_huge_page_size(void);
> -unsigned long get_free_hugepages(void);
>  
>  unsigned long hugetlb_nr_pages(unsigned long size);
>  void hugetlb_set_nr_pages(unsigned long size, unsigned long nr);
> +unsigned long hugetlb_free_pages(unsigned long size);
>  
>  static inline unsigned long hugetlb_nr_default_pages(void)
>  {
> @@ -117,4 +117,14 @@ static inline void hugetlb_set_nr_default_pages(unsigned long nr)
>  	hugetlb_set_nr_pages(size, nr);
>  }
>  
> +static inline unsigned long hugetlb_free_default_pages(void)
> +{
> +	unsigned long size = default_huge_page_size();
> +
> +	if (!size)
> +		return 0;
> +
> +	return hugetlb_free_pages(size);
> +}
> +
>  #endif /* __THP_SETTINGS_H__ */
> diff --git a/tools/testing/selftests/mm/hugetlb-madvise.c b/tools/testing/selftests/mm/hugetlb-madvise.c
> index 316384d919db..3c08eb6db6a2 100644
> --- a/tools/testing/selftests/mm/hugetlb-madvise.c
> +++ b/tools/testing/selftests/mm/hugetlb-madvise.c
> @@ -27,7 +27,7 @@
>  
>  #define validate_free_pages(exp_free)					\
>  	do {								\
> -		unsigned long fhp = get_free_hugepages();		\
> +		unsigned long fhp = hugetlb_free_default_pages();		\
>  		if (fhp != (exp_free))					\
>  			ksft_exit_fail_msg("Unexpected number of free "	\
>  				"huge pages %ld, expected %ld line %d\n", \
> @@ -68,7 +68,7 @@ int main(int argc, char **argv)
>  	if (!base_page_size)
>  		ksft_exit_fail_msg("Unable to determine base page size\n");
>  
> -	free_hugepages = get_free_hugepages();
> +	free_hugepages = hugetlb_free_default_pages();
>  	if (free_hugepages < MIN_FREE_PAGES)
>  		ksft_exit_skip("Not enough free huge pages (have %lu, need %d)\n", free_hugepages, MIN_FREE_PAGES);
>  
> diff --git a/tools/testing/selftests/mm/hugetlb_dio.c b/tools/testing/selftests/mm/hugetlb_dio.c
> index 81e3f7bc8e76..47019433ddaf 100644
> --- a/tools/testing/selftests/mm/hugetlb_dio.c
> +++ b/tools/testing/selftests/mm/hugetlb_dio.c
> @@ -93,7 +93,7 @@ static void run_dio_using_hugetlb(int fd, unsigned int start_off,
>  		ksft_exit_fail_perror("lseek failed\n");
>  
>  	/* Get the free huge pages before allocation */
> -	free_hpage_b = get_free_hugepages();
> +	free_hpage_b = hugetlb_free_default_pages();
>  	if (free_hpage_b == 0) {
>  		close(fd);
>  		ksft_exit_skip("No free hugepage, exiting!\n");
> @@ -121,7 +121,7 @@ static void run_dio_using_hugetlb(int fd, unsigned int start_off,
>  	munmap(orig_buffer, h_pagesize);
>  
>  	/* Get the free huge pages after unmap*/
> -	free_hpage_a = get_free_hugepages();
> +	free_hpage_a = hugetlb_free_default_pages();
>  
>  	ksft_print_msg("No. Free pages before allocation : %d\n", free_hpage_b);
>  	ksft_print_msg("No. Free pages after munmap : %d\n", free_hpage_a);
> @@ -142,7 +142,7 @@ int main(void)
>  	ksft_print_header();
>  
>  	/* Check if huge pages are free */
> -	if (!get_free_hugepages())
> +	if (!hugetlb_free_default_pages())
>  		ksft_exit_skip("No free hugepage, exiting\n");
>  
>  	fd = open("/tmp", O_TMPFILE | O_RDWR | O_DIRECT, 0664);
> diff --git a/tools/testing/selftests/mm/hugetlb_fault_after_madv.c b/tools/testing/selftests/mm/hugetlb_fault_after_madv.c
> index abc3904c5268..c718dd065d53 100644
> --- a/tools/testing/selftests/mm/hugetlb_fault_after_madv.c
> +++ b/tools/testing/selftests/mm/hugetlb_fault_after_madv.c
> @@ -78,7 +78,7 @@ int main(void)
>  	ksft_print_msg("[INFO] detected default hugetlb page size: %zu KiB\n",
>  		       huge_page_size / 1024);
>  
> -	free_hugepages = get_free_hugepages();
> +	free_hugepages = hugetlb_free_default_pages();
>  	if (free_hugepages != 1) {
>  		ksft_exit_skip("This test needs one and only one page to execute. Got %lu\n",
>  			       free_hugepages);
> diff --git a/tools/testing/selftests/mm/hugetlb_madv_vs_map.c b/tools/testing/selftests/mm/hugetlb_madv_vs_map.c
> index ac60b4f18784..dfbd71a7f709 100644
> --- a/tools/testing/selftests/mm/hugetlb_madv_vs_map.c
> +++ b/tools/testing/selftests/mm/hugetlb_madv_vs_map.c
> @@ -89,7 +89,7 @@ int main(void)
>  	ksft_print_header();
>  	ksft_set_plan(1);
>  
> -	free_hugepages = get_free_hugepages();
> +	free_hugepages = hugetlb_free_default_pages();
>  
>  	if (free_hugepages != 1)
>  		ksft_exit_skip("This test needs one and only one page to execute. Got %lu\n",
> diff --git a/tools/testing/selftests/mm/uffd-stress.c b/tools/testing/selftests/mm/uffd-stress.c
> index e92a85463eb1..7e37cf3d27f6 100644
> --- a/tools/testing/selftests/mm/uffd-stress.c
> +++ b/tools/testing/selftests/mm/uffd-stress.c
> @@ -480,7 +480,7 @@ int main(int argc, char **argv)
>  	 * for racy extra reservation of hugepages.
>  	 */
>  	if (gopts->test_type == TEST_HUGETLB &&
> -	   get_free_hugepages() < 2 * (bytes / gopts->page_size) + gopts->nr_parallel - 1)
> +	   hugetlb_free_default_pages() < 2 * (bytes / gopts->page_size) + gopts->nr_parallel - 1)
>  		ksft_exit_skip("Skipping userfaultfd... not enough hugepages\n");
>  
>  	gopts->nr_pages_per_cpu = bytes / gopts->page_size / gopts->nr_parallel;