Re: [PATCH v2 13/53] selftests/mm: khugepaged: use ksefltest framework

Sarthak Sharma
2026-04-28T13:07:11Z

Hi Mike!

On 4/18/26 4:24 PM, Mike Rapoport wrote:
> From: "Mike Rapoport (Microsoft)" <rppt@kernel.org>
>
> Convert khugepaged tests to use kselftest framework for reporting and
> tracking successful and failing runs.
>
> The conversion is mostly about replacing printf()/perror() + exit() pairs
> with their ksft_ counterparts.
>
> The nice colored success and failure indications are left intact.
>
> Replace the progress report in collapse_compound_extreme() with a single
> ksft_print_msg() to avoid headache with formatting and make the test output
> more concise.
>
> Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
> ---
> tools/testing/selftests/mm/khugepaged.c | 311 ++++++++++--------------
> 1 file changed, 128 insertions(+), 183 deletions(-)
>
> diff --git a/tools/testing/selftests/mm/khugepaged.c b/tools/testing/selftests/mm/khugepaged.c
> index 56494eea5ab3..da365f850365 100644
> --- a/tools/testing/selftests/mm/khugepaged.c
> +++ b/tools/testing/selftests/mm/khugepaged.c
> @@ -83,12 +83,13 @@ static void success(const char *msg)
> static void fail(const char *msg)
> {
> printf(" \e[31m%s\e[0m\n", msg);
> - exit_status++;
> + exit_status = KSFT_FAIL;
> }
>
> static void skip(const char *msg)
> {
> printf(" \e[33m%s\e[0m\n", msg);
> + exit_status = KSFT_SKIP;
> }
>
> static void restore_settings_atexit(void)
> @@ -96,22 +97,23 @@ static void restore_settings_atexit(void)
> if (skip_settings_restore)
> return;
>
> - printf("Restore THP and khugepaged settings...");
> + ksft_print_msg("Restore THP and khugepaged settings...");
> thp_restore_settings();
> success("OK");
>
> skip_settings_restore = true;
> + ksft_finished();
> }
>
> static void restore_settings(int sig)
> {
> /* exit() will invoke the restore_settings_atexit handler. */
> - exit(sig ? EXIT_FAILURE : exit_status);
> + exit(sig ? KSFT_FAIL : exit_status);
> }
>
> static void save_settings(void)
> {
> - printf("Save THP and khugepaged settings...");
> + ksft_print_msg("Save THP and khugepaged settings...");
> if (file_ops && finfo.type == VMA_FILE)
> thp_set_read_ahead_path(finfo.dev_queue_read_ahead_path);
> thp_save_settings();
> @@ -135,19 +137,13 @@ static void get_finfo(const char *dir)
>
> finfo.dir = dir;
> stat(finfo.dir, &path_stat);
> - if (!S_ISDIR(path_stat.st_mode)) {
> - printf("%s: Not a directory (%s)\n", __func__, finfo.dir);
> - exit(EXIT_FAILURE);
> - }
> + if (!S_ISDIR(path_stat.st_mode))
> + ksft_exit_fail_msg("%s: Not a directory (%s)\n", __func__, finfo.dir);
> if (snprintf(finfo.path, sizeof(finfo.path), "%s/" TEST_FILE,
> - finfo.dir) >= sizeof(finfo.path)) {
> - printf("%s: Pathname is too long\n", __func__);
> - exit(EXIT_FAILURE);
> - }
> - if (statfs(finfo.dir, &fs)) {
> - perror("statfs()");
> - exit(EXIT_FAILURE);
> - }
> + finfo.dir) >= sizeof(finfo.path))
> + ksft_exit_fail_msg("%s: Pathname is too long\n", __func__);
> + if (statfs(finfo.dir, &fs))
> + ksft_exit_fail_perror("statfs()");
> finfo.type = fs.f_type == TMPFS_MAGIC ? VMA_SHMEM : VMA_FILE;
> if (finfo.type == VMA_SHMEM)
> return;
> @@ -155,40 +151,30 @@ static void get_finfo(const char *dir)
> /* Find owning device's queue/read_ahead_kb control */
> if (snprintf(path, sizeof(path), "/sys/dev/block/%d:%d/uevent",
> major(path_stat.st_dev), minor(path_stat.st_dev))
> - >= sizeof(path)) {
> - printf("%s: Pathname is too long\n", __func__);
> - exit(EXIT_FAILURE);
> - }
> - if (read_file(path, buf, sizeof(buf)) < 0) {
> - perror("read_file(read_num)");
> - exit(EXIT_FAILURE);
> - }
> + >= sizeof(path))
> + ksft_exit_fail_msg("%s: Pathname is too long\n", __func__);
> + if (read_file(path, buf, sizeof(buf)) < 0)
> + ksft_exit_fail_perror("read_file(read_num)");
> if (strstr(buf, "DEVTYPE=disk")) {
> /* Found it */
> if (snprintf(finfo.dev_queue_read_ahead_path,
> sizeof(finfo.dev_queue_read_ahead_path),
> "/sys/dev/block/%d:%d/queue/read_ahead_kb",
> major(path_stat.st_dev), minor(path_stat.st_dev))
> - >= sizeof(finfo.dev_queue_read_ahead_path)) {
> - printf("%s: Pathname is too long\n", __func__);
> - exit(EXIT_FAILURE);
> - }
> + >= sizeof(finfo.dev_queue_read_ahead_path))
> + ksft_exit_fail_msg("%s: Pathname is too long\n", __func__);
> return;
> }
> - if (!strstr(buf, "DEVTYPE=partition")) {
> - printf("%s: Unknown device type: %s\n", __func__, path);
> - exit(EXIT_FAILURE);
> - }
> + if (!strstr(buf, "DEVTYPE=partition"))
> + ksft_exit_fail_msg("%s: Unknown device type: %s\n", __func__, path);
> /*
> * Partition of block device - need to find actual device.
> * Using naming convention that devnameN is partition of
> * device devname.
> */
> str = strstr(buf, "DEVNAME=");
> - if (!str) {
> - printf("%s: Could not read: %s", __func__, path);
> - exit(EXIT_FAILURE);
> - }
> + if (!str)
> + ksft_exit_fail_msg("%s: Could not read: %s", __func__, path);
> str += 8;
> end = str;
> while (*end) {
> @@ -197,16 +183,13 @@ static void get_finfo(const char *dir)
> if (snprintf(finfo.dev_queue_read_ahead_path,
> sizeof(finfo.dev_queue_read_ahead_path),
> "/sys/block/%s/queue/read_ahead_kb",
> - str) >= sizeof(finfo.dev_queue_read_ahead_path)) {
> - printf("%s: Pathname is too long\n", __func__);
> - exit(EXIT_FAILURE);
> - }
> + str) >= sizeof(finfo.dev_queue_read_ahead_path))
> + ksft_exit_fail_msg("%s: Pathname is too long\n", __func__);
> return;
> }
> ++end;
> }
> - printf("%s: Could not read: %s\n", __func__, path);
> - exit(EXIT_FAILURE);
> + ksft_exit_fail_msg("%s: Could not read: %s\n", __func__, path);
> }
>
> static bool check_swap(void *addr, unsigned long size)
> @@ -219,26 +202,19 @@ static bool check_swap(void *addr, unsigned long size)
>
> ret = snprintf(addr_pattern, MAX_LINE_LENGTH, "%08lx-",
> (unsigned long) addr);
> - if (ret >= MAX_LINE_LENGTH) {
> - printf("%s: Pattern is too long\n", __func__);
> - exit(EXIT_FAILURE);
> - }
> -
> + if (ret >= MAX_LINE_LENGTH)
> + ksft_exit_fail_msg("%s: Pattern is too long\n", __func__);
>
> fp = fopen(PID_SMAPS, "r");
> - if (!fp) {
> - printf("%s: Failed to open file %s\n", __func__, PID_SMAPS);
> - exit(EXIT_FAILURE);
> - }
> + if (!fp)
> + ksft_exit_fail_msg("%s: Failed to open file %s\n", __func__, PID_SMAPS);
> if (!check_for_pattern(fp, addr_pattern, buffer, sizeof(buffer)))
> goto err_out;
>
> ret = snprintf(addr_pattern, MAX_LINE_LENGTH, "Swap:%19ld kB",
> size >> 10);
> - if (ret >= MAX_LINE_LENGTH) {
> - printf("%s: Pattern is too long\n", __func__);
> - exit(EXIT_FAILURE);
> - }
> + if (ret >= MAX_LINE_LENGTH)
> + ksft_exit_fail_msg("%s: Pattern is too long\n", __func__);
> /*
> * Fetch the Swap: in the same block and check whether it got
> * the expected number of hugeepages next.
> @@ -261,10 +237,8 @@ static void *alloc_mapping(int nr)
>
> p = mmap(BASE_ADDR, nr * hpage_pmd_size, PROT_READ | PROT_WRITE,
> MAP_ANONYMOUS | MAP_PRIVATE, -1, 0);
> - if (p != BASE_ADDR) {
> - printf("Failed to allocate VMA at %p\n", BASE_ADDR);
> - exit(EXIT_FAILURE);
> - }
> + if (p != BASE_ADDR)
> + ksft_exit_fail_msg("Failed to allocate VMA at %p\n", BASE_ADDR);
>
> return p;
> }
> @@ -314,19 +288,13 @@ static void *alloc_hpage(struct mem_ops *ops)
> * khugepaged on low-load system (like a test machine), which
> * would cause MADV_COLLAPSE to fail with EAGAIN.
> */
> - printf("Allocate huge page...");
> - if (madvise_collapse_retry(p, hpage_pmd_size)) {
> - perror("madvise(MADV_COLLAPSE)");
> - exit(EXIT_FAILURE);
> - }
> - if (!ops->check_huge(p, 1)) {
> - perror("madvise(MADV_COLLAPSE)");
> - exit(EXIT_FAILURE);
> - }
> - if (madvise(p, hpage_pmd_size, MADV_HUGEPAGE)) {
> - perror("madvise(MADV_HUGEPAGE)");
> - exit(EXIT_FAILURE);
> - }
> + ksft_print_msg("Allocate huge page...");
> + if (madvise_collapse_retry(p, hpage_pmd_size))
> + ksft_exit_fail_perror("madvise(MADV_COLLAPSE)");
> + if (!ops->check_huge(p, 1))
> + ksft_exit_fail_perror("madvise(MADV_COLLAPSE)");
> + if (madvise(p, hpage_pmd_size, MADV_HUGEPAGE))
> + ksft_exit_fail_perror("madvise(MADV_HUGEPAGE)");
> success("OK");
> return p;
> }
> @@ -336,11 +304,9 @@ static void validate_memory(int *p, unsigned long start, unsigned long end)
> int i;
>
> for (i = start / page_size; i < end / page_size; i++) {
> - if (p[i * page_size / sizeof(*p)] != i + 0xdead0000) {
> - printf("Page %d is corrupted: %#x\n",
> - i, p[i * page_size / sizeof(*p)]);
> - exit(EXIT_FAILURE);
> - }
> + if (p[i * page_size / sizeof(*p)] != i + 0xdead0000)
> + ksft_exit_fail_msg("Page %d is corrupted: %#x\n",
> + i, p[i * page_size / sizeof(*p)]);
> }
> }
>
> @@ -371,14 +337,12 @@ static void *file_setup_area(int nr_hpages)
> unsigned long size;
>
> unlink(finfo.path); /* Cleanup from previous failed tests */
> - printf("Creating %s for collapse%s...", finfo.path,
> - finfo.type == VMA_SHMEM ? " (tmpfs)" : "");
> + ksft_print_msg("Creating %s for collapse%s...", finfo.path,
> + finfo.type == VMA_SHMEM ? " (tmpfs)" : "");
> fd = open(finfo.path, O_DSYNC | O_CREAT | O_RDWR | O_TRUNC | O_EXCL,
> 777);
> - if (fd < 0) {
> - perror("open()");
> - exit(EXIT_FAILURE);
> - }
> + if (fd < 0)
> + ksft_exit_fail_perror("open()");
>
> size = nr_hpages * hpage_pmd_size;
> p = alloc_mapping(nr_hpages);
> @@ -388,18 +352,14 @@ static void *file_setup_area(int nr_hpages)
> munmap(p, size);
> success("OK");
>
> - printf("Opening %s read only for collapse...", finfo.path);
> + ksft_print_msg("Opening %s read only for collapse...", finfo.path);
> finfo.fd = open(finfo.path, O_RDONLY, 777);
> - if (finfo.fd < 0) {
> - perror("open()");
> - exit(EXIT_FAILURE);
> - }
> + if (finfo.fd < 0)
> + ksft_exit_fail_perror("open()");
> p = mmap(BASE_ADDR, size, PROT_READ,
> MAP_PRIVATE, finfo.fd, 0);
> - if (p == MAP_FAILED || p != BASE_ADDR) {
> - perror("mmap()");
> - exit(EXIT_FAILURE);
> - }
> + if (p == MAP_FAILED || p != BASE_ADDR)
> + ksft_exit_fail_perror("mmap()");
>
> /* Drop page cache */
> write_file("/proc/sys/vm/drop_caches", "3", 2);
> @@ -416,10 +376,8 @@ static void file_cleanup_area(void *p, unsigned long size)
>
> static void file_fault(void *p, unsigned long start, unsigned long end)
> {
> - if (madvise(((char *)p) + start, end - start, MADV_POPULATE_READ)) {
> - perror("madvise(MADV_POPULATE_READ");
> - exit(EXIT_FAILURE);
> - }
> + if (madvise(((char *)p) + start, end - start, MADV_POPULATE_READ))
> + ksft_exit_fail_perror("madvise(MADV_POPULATE_READ");
> }
>
> static bool file_check_huge(void *addr, int nr_hpages)
> @@ -441,20 +399,14 @@ static void *shmem_setup_area(int nr_hpages)
> unsigned long size = nr_hpages * hpage_pmd_size;
>
> finfo.fd = memfd_create("khugepaged-selftest-collapse-shmem", 0);
> - if (finfo.fd < 0) {
> - perror("memfd_create()");
> - exit(EXIT_FAILURE);
> - }
> - if (ftruncate(finfo.fd, size)) {
> - perror("ftruncate()");
> - exit(EXIT_FAILURE);
> - }
> + if (finfo.fd < 0)
> + ksft_exit_fail_perror("memfd_create()");
> + if (ftruncate(finfo.fd, size))
> + ksft_exit_fail_perror("ftruncate()");
> p = mmap(BASE_ADDR, size, PROT_READ | PROT_WRITE, MAP_SHARED, finfo.fd,
> 0);
> - if (p != BASE_ADDR) {
> - perror("mmap()");
> - exit(EXIT_FAILURE);
> - }
> + if (p != BASE_ADDR)
> + ksft_exit_fail_perror("mmap()");
> return p;
> }
>
> @@ -499,7 +451,7 @@ static void __madvise_collapse(const char *msg, char *p, int nr_hpages,
> int ret;
> struct thp_settings settings = *thp_current_settings();
>
> - printf("%s...", msg);
> + ksft_print_msg("%s...", msg);
>
> /*
> * Prevent khugepaged interference and tests that MADV_COLLAPSE
> @@ -526,10 +478,8 @@ static void madvise_collapse(const char *msg, char *p, int nr_hpages,
> struct mem_ops *ops, bool expect)
> {
> /* Sanity check */
> - if (!ops->check_huge(p, 0)) {
> - printf("Unexpected huge page\n");
> - exit(EXIT_FAILURE);
> - }
> + if (!ops->check_huge(p, 0))
> + ksft_exit_fail_msg("Unexpected huge page\n");
> __madvise_collapse(msg, p, nr_hpages, ops, expect);
> }
>
> @@ -541,17 +491,15 @@ static bool wait_for_scan(const char *msg, char *p, int nr_hpages,
> int timeout = 6; /* 3 seconds */
>
> /* Sanity check */
> - if (!ops->check_huge(p, 0)) {
> - printf("Unexpected huge page\n");
> - exit(EXIT_FAILURE);
> - }
> + if (!ops->check_huge(p, 0))
> + ksft_exit_fail_msg("Unexpected huge page\n");
>
> madvise(p, nr_hpages * hpage_pmd_size, MADV_HUGEPAGE);
>
> /* Wait until the second full_scan completed */
> full_scans = thp_read_num("khugepaged/full_scans") + 2;
>
> - printf("%s...", msg);
> + ksft_print_msg("%s...", msg);
> while (timeout--) {
> if (ops->check_huge(p, nr_hpages))
> break;
> @@ -621,7 +569,7 @@ static void alloc_at_fault(void)
>
> p = alloc_mapping(1);
> *p = 1;
> - printf("Allocate huge page on fault...");
> + ksft_print_msg("Allocate huge page on fault...");
> if (check_huge_anon(p, 1, hpage_pmd_size))
> success("OK");
> else
> @@ -630,12 +578,14 @@ static void alloc_at_fault(void)
> thp_pop_settings();
>
> madvise(p, page_size, MADV_DONTNEED);
> - printf("Split huge PMD on MADV_DONTNEED...");
> + ksft_print_msg("Split huge PMD on MADV_DONTNEED...");
> if (check_huge_anon(p, 0, hpage_pmd_size))
> success("OK");
> else
> fail("Fail");
> munmap(p, hpage_pmd_size);
> +
> + ksft_test_result_report(exit_status, "allocate on fault and split\n");
> }
>
> static void collapse_full(struct collapse_context *c, struct mem_ops *ops)
> @@ -650,6 +600,8 @@ static void collapse_full(struct collapse_context *c, struct mem_ops *ops)
> ops, true);
> validate_memory(p, 0, size);
> ops->cleanup_area(p, size);
> +
> + ksft_test_result_report(exit_status, "%s\n", __func__);
> }
>
> static void collapse_empty(struct collapse_context *c, struct mem_ops *ops)
> @@ -659,6 +611,7 @@ static void collapse_empty(struct collapse_context *c, struct mem_ops *ops)
> p = ops->setup_area(1);
> c->collapse("Do not collapse empty PTE table", p, 1, ops, false);
> ops->cleanup_area(p, hpage_pmd_size);
> + ksft_test_result_report(exit_status, "%s\n", __func__);
> }
>
> static void collapse_single_pte_entry(struct collapse_context *c, struct mem_ops *ops)
> @@ -670,6 +623,7 @@ static void collapse_single_pte_entry(struct collapse_context *c, struct mem_ops
> c->collapse("Collapse PTE table with single PTE entry present", p,
> 1, ops, true);
> ops->cleanup_area(p, hpage_pmd_size);
> + ksft_test_result_report(exit_status, "%s\n", __func__);
> }
>
> static void collapse_max_ptes_none(struct collapse_context *c, struct mem_ops *ops)
> @@ -706,6 +660,7 @@ static void collapse_max_ptes_none(struct collapse_context *c, struct mem_ops *o
> skip:
> ops->cleanup_area(p, hpage_pmd_size);
> thp_pop_settings();
> + ksft_test_result_report(exit_status, "%s\n", __func__);
> }
>
> static void collapse_swapin_single_pte(struct collapse_context *c, struct mem_ops *ops)
> @@ -715,11 +670,9 @@ static void collapse_swapin_single_pte(struct collapse_context *c, struct mem_op
> p = ops->setup_area(1);
> ops->fault(p, 0, hpage_pmd_size);
>
> - printf("Swapout one page...");
> - if (madvise(p, page_size, MADV_PAGEOUT)) {
> - perror("madvise(MADV_PAGEOUT)");
> - exit(EXIT_FAILURE);
> - }
> + ksft_print_msg("Swapout one page...");
> + if (madvise(p, page_size, MADV_PAGEOUT))
> + ksft_exit_fail_perror("madvise(MADV_PAGEOUT)");
> if (check_swap(p, page_size)) {
> success("OK");
> } else {
> @@ -732,6 +685,7 @@ static void collapse_swapin_single_pte(struct collapse_context *c, struct mem_op
> validate_memory(p, 0, hpage_pmd_size);
> out:
> ops->cleanup_area(p, hpage_pmd_size);
> + ksft_test_result_report(exit_status, "%s\n", __func__);
> }
>
> static void collapse_max_ptes_swap(struct collapse_context *c, struct mem_ops *ops)
> @@ -742,11 +696,9 @@ static void collapse_max_ptes_swap(struct collapse_context *c, struct mem_ops *o
> p = ops->setup_area(1);
> ops->fault(p, 0, hpage_pmd_size);
>
> - printf("Swapout %d of %d pages...", max_ptes_swap + 1, hpage_pmd_nr);
> - if (madvise(p, (max_ptes_swap + 1) * page_size, MADV_PAGEOUT)) {
> - perror("madvise(MADV_PAGEOUT)");
> - exit(EXIT_FAILURE);
> - }
> + ksft_print_msg("Swapout %d of %d pages...", max_ptes_swap + 1, hpage_pmd_nr);
> + if (madvise(p, (max_ptes_swap + 1) * page_size, MADV_PAGEOUT))
> + ksft_exit_fail_perror("madvise(MADV_PAGEOUT)");
> if (check_swap(p, (max_ptes_swap + 1) * page_size)) {
> success("OK");
> } else {
> @@ -760,12 +712,10 @@ static void collapse_max_ptes_swap(struct collapse_context *c, struct mem_ops *o
>
> if (c->enforce_pte_scan_limits) {
> ops->fault(p, 0, hpage_pmd_size);
> - printf("Swapout %d of %d pages...", max_ptes_swap,
> + ksft_print_msg("Swapout %d of %d pages...", max_ptes_swap,
> hpage_pmd_nr);
> - if (madvise(p, max_ptes_swap * page_size, MADV_PAGEOUT)) {
> - perror("madvise(MADV_PAGEOUT)");
> - exit(EXIT_FAILURE);
> - }
> + if (madvise(p, max_ptes_swap * page_size, MADV_PAGEOUT))
> + ksft_exit_fail_perror("madvise(MADV_PAGEOUT)");
> if (check_swap(p, max_ptes_swap * page_size)) {
> success("OK");
> } else {
> @@ -779,6 +729,7 @@ static void collapse_max_ptes_swap(struct collapse_context *c, struct mem_ops *o
> }
> out:
> ops->cleanup_area(p, hpage_pmd_size);
> + ksft_test_result_report(exit_status, "%s\n", __func__);
> }
>
> static void collapse_single_pte_entry_compound(struct collapse_context *c, struct mem_ops *ops)
> @@ -792,7 +743,7 @@ static void collapse_single_pte_entry_compound(struct collapse_context *c, struc
> advise = MADV_REMOVE;
>
> madvise(p, hpage_pmd_size, MADV_NOHUGEPAGE);
> - printf("Split huge page leaving single PTE mapping compound page...");
> + ksft_print_msg("Split huge page leaving single PTE mapping compound page...");
> madvise(p + page_size, hpage_pmd_size - page_size, advise);
> if (ops->check_huge(p, 0))
> success("OK");
> @@ -803,6 +754,7 @@ static void collapse_single_pte_entry_compound(struct collapse_context *c, struc
> p, 1, ops, true);
> validate_memory(p, 0, page_size);
> ops->cleanup_area(p, hpage_pmd_size);
> + ksft_test_result_report(exit_status, "%s\n", __func__);
> }
>
> static void collapse_full_of_compound(struct collapse_context *c, struct mem_ops *ops)
> @@ -810,7 +762,7 @@ static void collapse_full_of_compound(struct collapse_context *c, struct mem_ops
> void *p;
>
> p = alloc_hpage(ops);
> - printf("Split huge page leaving single PTE page table full of compound pages...");
> + ksft_print_msg("Split huge page leaving single PTE page table full of compound pages...");
> madvise(p, page_size, MADV_NOHUGEPAGE);
> madvise(p, hpage_pmd_size, MADV_NOHUGEPAGE);
> if (ops->check_huge(p, 0))
> @@ -822,6 +774,7 @@ static void collapse_full_of_compound(struct collapse_context *c, struct mem_ops
> true);
> validate_memory(p, 0, hpage_pmd_size);
> ops->cleanup_area(p, hpage_pmd_size);
> + ksft_test_result_report(exit_status, "%s\n", __func__);
> }
>
> static void collapse_compound_extreme(struct collapse_context *c, struct mem_ops *ops)
> @@ -830,16 +783,12 @@ static void collapse_compound_extreme(struct collapse_context *c, struct mem_ops
> int i;
>
> p = ops->setup_area(1);
> + ksft_print_msg("Construct PTE page table full of different PTE-mapped compound pagesd\n");

A small typo here, "pagesd" should be "pages".

> for (i = 0; i < hpage_pmd_nr; i++) {
> - printf("\rConstruct PTE page table full of different PTE-mapped compound pages %3d/%d...",
> - i + 1, hpage_pmd_nr);
> -
> madvise(BASE_ADDR, hpage_pmd_size, MADV_HUGEPAGE);
> ops->fault(BASE_ADDR, 0, hpage_pmd_size);
> - if (!ops->check_huge(BASE_ADDR, 1)) {
> - printf("Failed to allocate huge page\n");
> - exit(EXIT_FAILURE);
> - }
> + if (!ops->check_huge(BASE_ADDR, 1))
> + ksft_exit_fail_msg("Failed to allocate huge page\n");

In case we are not able to allocate a hugepage at fault, should this be
reported as a per-test failure instead of bailing out the whole binary
with ksft_exit_fail_msg()? In alloc_at_fault(), a failure to allocate a
hugepage is reported as a normal test result via
ksft_test_result_report(), so should this case behave similarly or is it
intentionally treated as fatal? I realize it was being treated as fatal
before this patch as well, but just wanted to check whether that is
necessary.

Also, when ksft_exit_fail_msg() is called, totals are printed twice:
once from ksft_exit_fail_msg() itself, and then again when exit() runs
the restore_settings_atexit handler.

> madvise(BASE_ADDR, hpage_pmd_size, MADV_NOHUGEPAGE);
>
> p = mremap(BASE_ADDR - i * page_size,
> @@ -847,20 +796,16 @@ static void collapse_compound_extreme(struct collapse_context *c, struct mem_ops
> (i + 1) * page_size,
> MREMAP_MAYMOVE | MREMAP_FIXED,
> BASE_ADDR + 2 * hpage_pmd_size);
> - if (p == MAP_FAILED) {
> - perror("mremap+unmap");
> - exit(EXIT_FAILURE);
> - }
> + if (p == MAP_FAILED)
> + ksft_exit_fail_perror("mremap+unmap");
>
> p = mremap(BASE_ADDR + 2 * hpage_pmd_size,
> (i + 1) * page_size,
> (i + 1) * page_size + hpage_pmd_size,
> MREMAP_MAYMOVE | MREMAP_FIXED,
> BASE_ADDR - (i + 1) * page_size);
> - if (p == MAP_FAILED) {
> - perror("mremap+alloc");
> - exit(EXIT_FAILURE);
> - }
> + if (p == MAP_FAILED)
> + ksft_exit_fail_perror("mremap+alloc");
> }
>
> ops->cleanup_area(BASE_ADDR, hpage_pmd_size);
> @@ -875,6 +820,7 @@ static void collapse_compound_extreme(struct collapse_context *c, struct mem_ops
>
> validate_memory(p, 0, hpage_pmd_size);
> ops->cleanup_area(p, hpage_pmd_size);
> + ksft_test_result_report(exit_status, "%s\n", __func__);
> }
>
> static void collapse_fork(struct collapse_context *c, struct mem_ops *ops)
> @@ -884,18 +830,17 @@ static void collapse_fork(struct collapse_context *c, struct mem_ops *ops)
>
> p = ops->setup_area(1);
>
> - printf("Allocate small page...");
> + ksft_print_msg("Allocate small page...");
> ops->fault(p, 0, page_size);
> if (ops->check_huge(p, 0))
> success("OK");
> else
> fail("Fail");
>
> - printf("Share small page over fork()...");
> + ksft_print_msg("Share small page over fork()...");
> if (!fork()) {
> /* Do not touch settings on child exit */
> skip_settings_restore = true;
> - exit_status = 0;
>
> if (ops->check_huge(p, 0))
> success("OK");
> @@ -912,15 +857,16 @@ static void collapse_fork(struct collapse_context *c, struct mem_ops *ops)
> }
>
> wait(&wstatus);
> - exit_status += WEXITSTATUS(wstatus);
> + exit_status = WEXITSTATUS(wstatus);
>
> - printf("Check if parent still has small page...");
> + ksft_print_msg("Check if parent still has small page...");
> if (ops->check_huge(p, 0))
> success("OK");
> else
> fail("Fail");
> validate_memory(p, 0, page_size);
> ops->cleanup_area(p, hpage_pmd_size);
> + ksft_test_result_report(exit_status, "%s\n", __func__);
> }
>
> static void collapse_fork_compound(struct collapse_context *c, struct mem_ops *ops)
> @@ -929,18 +875,17 @@ static void collapse_fork_compound(struct collapse_context *c, struct mem_ops *o
> void *p;
>
> p = alloc_hpage(ops);
> - printf("Share huge page over fork()...");
> + ksft_print_msg("Share huge page over fork()...");
> if (!fork()) {
> /* Do not touch settings on child exit */
> skip_settings_restore = true;
> - exit_status = 0;
>
> if (ops->check_huge(p, 1))
> success("OK");
> else
> fail("Fail");
>
> - printf("Split huge page PMD in child process...");
> + ksft_print_msg("Split huge page PMD in child process...");
> madvise(p, page_size, MADV_NOHUGEPAGE);
> madvise(p, hpage_pmd_size, MADV_NOHUGEPAGE);
> if (ops->check_huge(p, 0))
> @@ -961,15 +906,16 @@ static void collapse_fork_compound(struct collapse_context *c, struct mem_ops *o
> }
>
> wait(&wstatus);
> - exit_status += WEXITSTATUS(wstatus);
> + exit_status = WEXITSTATUS(wstatus);
>
> - printf("Check if parent still has huge page...");
> + ksft_print_msg("Check if parent still has huge page...");
> if (ops->check_huge(p, 1))
> success("OK");
> else
> fail("Fail");
> validate_memory(p, 0, hpage_pmd_size);
> ops->cleanup_area(p, hpage_pmd_size);
> + ksft_test_result_report(exit_status, "%s\n", __func__);
> }
>
> static void collapse_max_ptes_shared(struct collapse_context *c, struct mem_ops *ops)
> @@ -979,18 +925,17 @@ static void collapse_max_ptes_shared(struct collapse_context *c, struct mem_ops
> void *p;
>
> p = alloc_hpage(ops);
> - printf("Share huge page over fork()...");
> + ksft_print_msg("Share huge page over fork()...");
> if (!fork()) {
> /* Do not touch settings on child exit */
> skip_settings_restore = true;
> - exit_status = 0;
>
> if (ops->check_huge(p, 1))
> success("OK");
> else
> fail("Fail");
>
> - printf("Trigger CoW on page %d of %d...",
> + ksft_print_msg("Trigger CoW on page %d of %d...",
> hpage_pmd_nr - max_ptes_shared - 1, hpage_pmd_nr);
> ops->fault(p, 0, (hpage_pmd_nr - max_ptes_shared - 1) * page_size);
> if (ops->check_huge(p, 0))
> @@ -1002,7 +947,7 @@ static void collapse_max_ptes_shared(struct collapse_context *c, struct mem_ops
> 1, ops, !c->enforce_pte_scan_limits);
>
> if (c->enforce_pte_scan_limits) {
> - printf("Trigger CoW on page %d of %d...",
> + ksft_print_msg("Trigger CoW on page %d of %d...",
> hpage_pmd_nr - max_ptes_shared, hpage_pmd_nr);
> ops->fault(p, 0, (hpage_pmd_nr - max_ptes_shared) *
> page_size);
> @@ -1021,15 +966,16 @@ static void collapse_max_ptes_shared(struct collapse_context *c, struct mem_ops
> }
>
> wait(&wstatus);
> - exit_status += WEXITSTATUS(wstatus);
> + exit_status = WEXITSTATUS(wstatus);
>
> - printf("Check if parent still has huge page...");
> + ksft_print_msg("Check if parent still has huge page...");
> if (ops->check_huge(p, 1))
> success("OK");
> else
> fail("Fail");
> validate_memory(p, 0, hpage_pmd_size);
> ops->cleanup_area(p, hpage_pmd_size);
> + ksft_test_result_report(exit_status, "%s\n", __func__);
> }
>
> static void madvise_collapse_existing_thps(struct collapse_context *c,
> @@ -1046,6 +992,7 @@ static void madvise_collapse_existing_thps(struct collapse_context *c,
> __madvise_collapse("Re-collapse PMD-mapped hugepage", p, 1, ops, true);
> validate_memory(p, 0, hpage_pmd_size);
> ops->cleanup_area(p, hpage_pmd_size);
> + ksft_test_result_report(exit_status, "%s\n", __func__);
> }
>
> /*
> @@ -1073,6 +1020,7 @@ static void madvise_retracted_page_tables(struct collapse_context *c,
> true);
> validate_memory(p, 0, size);
> ops->cleanup_area(p, size);
> + ksft_test_result_report(exit_status, "%s\n", __func__);
> }
>
> static void usage(void)
> @@ -1176,10 +1124,8 @@ static int nr_test_cases;
>
> #define TEST(t, c, o) do { \
> if (c && o) { \
> - if (nr_test_cases >= MAX_TEST_CASES) { \
> - printf("MAX_ADD_CASES is too small\n"); \
> - exit(EXIT_FAILURE); \
> - } \
> + if (nr_test_cases >= MAX_TEST_CASES) \
> + ksft_exit_fail_msg("MAX_ADD_CASES is too small\n"); \
> test_cases[nr_test_cases++] = (struct test_case){ \
> .ctx = c, \
> .ops = o, \
> @@ -1212,10 +1158,10 @@ int main(int argc, char **argv)
> .read_ahead_kb = 0,
> };
>
> - if (!thp_is_enabled()) {
> - printf("Transparent Hugepages not available\n");
> - return KSFT_SKIP;
> - }
> + ksft_print_header();
> +
> + if (!thp_is_enabled())
> + ksft_exit_skip("Transparent Hugepages not available\n");
>
> parse_test_type(argc, argv);
>
> @@ -1223,10 +1169,8 @@ int main(int argc, char **argv)
>
> page_size = getpagesize();
> hpage_pmd_size = read_pmd_pagesize();
> - if (!hpage_pmd_size) {
> - printf("Reading PMD pagesize failed");
> - exit(EXIT_FAILURE);
> - }
> + if (!hpage_pmd_size)
> + ksft_exit_fail_msg("Reading PMD pagesize failed\n");
> hpage_pmd_nr = hpage_pmd_size / page_size;
> hpage_pmd_order = __builtin_ctz(hpage_pmd_nr);
>
> @@ -1242,8 +1186,6 @@ int main(int argc, char **argv)
> save_settings();
> thp_push_settings(&default_settings);

Also, can save_settings() and thp_push_settings() be moved below
ksft_set_plan(), preserving their order? Since save_settings() is
printing a debug line of its own, it would look better if ksft plan is
printed just below the TAP version line.

>
> - alloc_at_fault();
> -
> TEST(collapse_full, khugepaged_context, anon_ops);
> TEST(collapse_full, khugepaged_context, file_ops);
> TEST(collapse_full, khugepaged_context, shmem_ops);
> @@ -1305,11 +1247,14 @@ int main(int argc, char **argv)
> TEST(madvise_retracted_page_tables, madvise_context, file_ops);
> TEST(madvise_retracted_page_tables, madvise_context, shmem_ops);
>
> + ksft_set_plan(nr_test_cases + 1);
> +
> + alloc_at_fault();
> for (int i = 0; i < nr_test_cases; i++) {
> struct test_case *t = &test_cases[i];
>
> exit_status = KSFT_PASS;
> - printf("\nRun test: %s: (%s:%s)\n", t->desc, t->ctx->name, t->ops->name);
> + ksft_print_msg("\nRun test: %s: (%s:%s)\n", t->desc, t->ctx->name, t->ops->name);
> t->fn(t->ctx, t->ops);
> }
>