Hi,
On Wed, Aug 12, 2026 at 08:08:21PM +0800, Song Hu wrote:
> hugetlb-soft-offline toggles /proc/sys/vm/enable_soft_offline between 1 and
> 0 (test_soft_offline_common(1) then (0)) and leaves it at 0 when it
> finishes, silently disabling soft offlining for the whole system after the
> run. Read the original value before the test and restore it before
> ksft_finished().
>
> Signed-off-by: Song Hu <[email protected]>
> ---
> .../selftests/mm/hugetlb-soft-offline.c | 24 +++++++++++++++++++
> 1 file changed, 24 insertions(+)
>
> diff --git a/tools/testing/selftests/mm/hugetlb-soft-offline.c
> b/tools/testing/selftests/mm/hugetlb-soft-offline.c
> index bc202e4ed2bd..35dcf661b091 100644
> --- a/tools/testing/selftests/mm/hugetlb-soft-offline.c
> +++ b/tools/testing/selftests/mm/hugetlb-soft-offline.c
> @@ -99,6 +99,23 @@ static int set_enable_soft_offline(int value)
> return 0;
> }
>
> +static int get_enable_soft_offline(void)
> +{
> + FILE *fp = fopen("/proc/sys/vm/enable_soft_offline", "r");
> + int value = -1;
> +
> + if (!fp) {
> + ksft_perror(EPREFIX "failed to read enable_soft_offline");
> + return -1;
> + }
> + if (fscanf(fp, "%d", &value) != 1) {
> + ksft_perror(EPREFIX "failed to parse enable_soft_offline");
> + value = -1;
> + }
> + fclose(fp);
> + return value;
> +}
We have read_num() in vm_util and write_num() that can replace
set_enable_soft_offline().
> +
> static int create_hugetlbfs_file(struct statfs *file_stat)
> {
> int fd;
> @@ -185,6 +202,8 @@ static void test_soft_offline_common(int
> enable_soft_offline)
>
> int main(int argc, char **argv)
> {
> + int orig;
Please spell out what orig is this.
> +
> ksft_print_header();
>
> if (!hugetlb_setup_default(8))
> @@ -192,8 +211,13 @@ int main(int argc, char **argv)
>
> ksft_set_plan(2);
>
> + orig = get_enable_soft_offline();
> +
> test_soft_offline_common(1);
> test_soft_offline_common(0);
>
> + if (orig >= 0)
> + set_enable_soft_offline(orig);
> +
> ksft_finished();
> }
> --
> 2.43.0
>
--
Sincerely yours,
Mike.
