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.
Save the original value before the test and restore it from an atexit() handler, so the sysctl is also restored when the test exits early via ksft_exit_fail_msg(), as hugepage_restore_settings_atexit() in hugepage_settings.c already does. Use read_num()/write_num() from vm_util instead of the hand-rolled popen()/fopen() helpers. Signed-off-by: Song Hu <[email protected]> --- .../selftests/mm/hugetlb-soft-offline.c | 35 +++++++------------ 1 file changed, 12 insertions(+), 23 deletions(-) diff --git a/tools/testing/selftests/mm/hugetlb-soft-offline.c b/tools/testing/selftests/mm/hugetlb-soft-offline.c index bc202e4ed2bd..86259921d54c 100644 --- a/tools/testing/selftests/mm/hugetlb-soft-offline.c +++ b/tools/testing/selftests/mm/hugetlb-soft-offline.c @@ -23,6 +23,7 @@ #include <sys/types.h> #include "kselftest.h" +#include "vm_util.h" #include "hugepage_settings.h" #ifndef MADV_SOFT_OFFLINE @@ -31,6 +32,8 @@ #define EPREFIX " !!! " +#define ENABLE_SOFT_OFFLINE_PATH "/proc/sys/vm/enable_soft_offline" + static int do_soft_offline(int fd, size_t len, int expect_errno) { char *filemap = NULL; @@ -77,26 +80,12 @@ static int do_soft_offline(int fd, size_t len, int expect_errno) return ret; } -static int set_enable_soft_offline(int value) -{ - char cmd[256] = {0}; - FILE *cmdfile = NULL; - - if (value != 0 && value != 1) - return -EINVAL; - - sprintf(cmd, "echo %d > /proc/sys/vm/enable_soft_offline", value); - cmdfile = popen(cmd, "r"); - - if (cmdfile) - ksft_print_msg("enable_soft_offline => %d\n", value); - else { - ksft_perror(EPREFIX "failed to set enable_soft_offline"); - return errno; - } +static unsigned long orig_enable_soft_offline = -1UL; - pclose(cmdfile); - return 0; +static void restore_enable_soft_offline(void) +{ + if (orig_enable_soft_offline != -1UL) + write_num(ENABLE_SOFT_OFFLINE_PATH, orig_enable_soft_offline); } static int create_hugetlbfs_file(struct statfs *file_stat) @@ -145,10 +134,7 @@ static void test_soft_offline_common(int enable_soft_offline) hugepagesize_kb = file_stat.f_bsize / 1024; ksft_print_msg("Hugepagesize is %ldkB\n", hugepagesize_kb); - if (set_enable_soft_offline(enable_soft_offline) != 0) { - close(fd); - ksft_exit_fail_msg("Failed to set enable_soft_offline\n"); - } + write_num(ENABLE_SOFT_OFFLINE_PATH, enable_soft_offline); nr_hugepages_before = hugetlb_nr_default_pages(); @@ -192,6 +178,9 @@ int main(int argc, char **argv) ksft_set_plan(2); + orig_enable_soft_offline = read_num(ENABLE_SOFT_OFFLINE_PATH); + atexit(restore_enable_soft_offline); + test_soft_offline_common(1); test_soft_offline_common(0); -- 2.43.0
