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

Sarthak Sharma
2026-05-06T11:04:49Z

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;