[4/7] selftests/mm: khugepaged: conform test to TAP format output

  Conform the layout, informational and status messages to TAP. No
functional change is intended other than the layout of output messages.

Signed-off-by: Muhammad Usama Anjum <usama.anjum@collabora.com>
---
 tools/testing/selftests/mm/khugepaged.c | 378 ++++++++++--------------
 1 file changed, 160 insertions(+), 218 deletions(-)
  

Sorry, forgot to remvove 2 lines. I'll resend if there aren't any comments
until tomorrow.

On 1/11/24 4:56 PM, Muhammad Usama Anjum wrote:
> Conform the layout, informational and status messages to TAP. No
> functional change is intended other than the layout of output messages.
> 
> Signed-off-by: Muhammad Usama Anjum <usama.anjum@collabora.com>
> ---
>  tools/testing/selftests/mm/khugepaged.c | 378 ++++++++++--------------
>  1 file changed, 160 insertions(+), 218 deletions(-)
> 
> diff --git a/tools/testing/selftests/mm/khugepaged.c b/tools/testing/selftests/mm/khugepaged.c
> index 829320a519e7..0ed82b8b31fa 100644
> --- a/tools/testing/selftests/mm/khugepaged.c
> +++ b/tools/testing/selftests/mm/khugepaged.c
> @@ -23,6 +23,7 @@
>  
>  #include "vm_util.h"
>  #include "thp_settings.h"
> +#include "../kselftest.h"
>  
>  #define BASE_ADDR ((void *)(1UL << 30))
>  static unsigned long hpage_pmd_size;
> @@ -73,22 +74,20 @@ struct file_info {
>  
>  static struct file_info finfo;
>  static bool skip_settings_restore;
> -static int exit_status;
>  
>  static void success(const char *msg)
>  {
> -	printf(" \e[32m%s\e[0m\n", msg);
> +	ksft_test_result_pass("%s\n", msg);
>  }
>  
>  static void fail(const char *msg)
>  {
> -	printf(" \e[31m%s\e[0m\n", msg);
> -	exit_status++;
> +	ksft_test_result_fail("%s\n", msg);
>  }
>  
>  static void skip(const char *msg)
>  {
> -	printf(" \e[33m%s\e[0m\n", msg);
> +	ksft_test_result_skip("\e%s\n", msg);
>  }
>  
>  static void restore_settings_atexit(void)
> @@ -96,9 +95,8 @@ static void restore_settings_atexit(void)
>  	if (skip_settings_restore)
>  		return;
>  
> -	printf("Restore THP and khugepaged settings...");
>  	thp_restore_settings();
> -	success("OK");
> +	ksft_print_msg("Restored THP and khugepaged settings...\n");
>  
>  	skip_settings_restore = true;
>  }
> @@ -106,12 +104,12 @@ static void restore_settings_atexit(void)
>  static void restore_settings(int sig)
>  {
>  	/* exit() will invoke the restore_settings_atexit handler. */
> -	exit(sig ? EXIT_FAILURE : exit_status);
> +	ksft_finished();
>  }
>  
>  static void save_settings(void)
>  {
> -	printf("Save THP and khugepaged settings...");
> +	ksft_print_msg("Save THP and khugepaged settings...\n");
>  	if (file_ops && finfo.type == VMA_FILE)
>  		thp_set_read_ahead_path(finfo.dev_queue_read_ahead_path);
>  	thp_save_settings();
> @@ -135,60 +133,50 @@ 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_msg("statfs(): %s\n", strerror(errno));
> +
>  	finfo.type = fs.f_type == TMPFS_MAGIC ? VMA_SHMEM : VMA_FILE;
>  	if (finfo.type == VMA_SHMEM)
>  		return;
>  
>  	/* 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);
> -	}
> +		     major(path_stat.st_dev), minor(path_stat.st_dev)) >= sizeof(path))
> +		ksft_exit_fail_msg("%s: Pathname is too long\n", __func__);
> +
> +	if (read_file(path, buf, sizeof(buf)) < 0)
> +		ksft_exit_fail_msg("read_file(read_num): %s\n", strerror(errno));
> +
>  	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: %s\n", __func__,
> +					   strerror(errno));
>  		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 +185,14 @@ 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 +205,21 @@ 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 +242,8 @@ 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 +293,16 @@ 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...\n");
> +	if (madvise_collapse_retry(p, hpage_pmd_size))
> +		ksft_exit_fail_msg("madvise(MADV_COLLAPSE): %s\n", strerror(errno));
> +
> +	if (!ops->check_huge(p, 1))
> +		ksft_exit_fail_msg("madvise(MADV_COLLAPSE): %s\n", strerror(errno));
> +
> +	if (madvise(p, hpage_pmd_size, MADV_HUGEPAGE))
> +		ksft_exit_fail_msg("madvise(MADV_HUGEPAGE): %s\n", strerror(errno));
> +
>  	success("OK");
>  	return p;
>  }
> @@ -335,13 +311,12 @@ 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);
> -		}
> -	}
> +	for (i = start / page_size; i < end / page_size; i++)
> +		if (p[i * page_size / sizeof(*p)] != i + 0xdead0000)
> +			ksft_print_msg("Page %d is corrupted: %#x\n",
> +				       i, p[i * page_size / sizeof(*p)]);
> +
> +	ksft_test_result(i == end/page_size, "Validated memory\n");
>  }
>  
>  static void *anon_setup_area(int nr_hpages)
> @@ -371,14 +346,12 @@ 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...\n", 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_msg("open(): %s\n", strerror(errno));
>  
>  	size = nr_hpages * hpage_pmd_size;
>  	p = alloc_mapping(nr_hpages);
> @@ -388,18 +361,15 @@ 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...\n", 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_msg("open(): %s\n", strerror(errno));
> +
>  	p = mmap(BASE_ADDR, size, PROT_READ | PROT_EXEC,
>  		 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_msg("mmap(): %s\n", strerror(errno));
>  
>  	/* Drop page cache */
>  	write_file("/proc/sys/vm/drop_caches", "3", 2);
> @@ -416,10 +386,8 @@ 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_msg("madvise(MADV_POPULATE_READ: %s\n", strerror(errno));
>  }
>  
>  static bool file_check_huge(void *addr, int nr_hpages)
> @@ -430,7 +398,7 @@ static bool file_check_huge(void *addr, int nr_hpages)
>  	case VMA_SHMEM:
>  		return check_huge_shmem(addr, nr_hpages, hpage_pmd_size);
>  	default:
> -		exit(EXIT_FAILURE);
> +		ksft_exit_fail_msg("Wrong type\n");
>  		return false;
>  	}
>  }
> @@ -441,20 +409,16 @@ 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);
> -	}
> -	p = mmap(BASE_ADDR, size, PROT_READ | PROT_WRITE, MAP_SHARED, finfo.fd,
> -		 0);
> -	if (p != BASE_ADDR) {
> -		perror("mmap()");
> -		exit(EXIT_FAILURE);
> -	}
> +	if (finfo.fd < 0)
> +		ksft_exit_fail_msg("memfd_create(): %s\n", strerror(errno));
> +
> +	if (ftruncate(finfo.fd, size))
> +		ksft_exit_fail_msg("ftruncate(): %s\n", strerror(errno));
> +
> +	p = mmap(BASE_ADDR, size, PROT_READ | PROT_WRITE, MAP_SHARED, finfo.fd, 0);
> +	if (p != BASE_ADDR)
> +		ksft_exit_fail_msg("mmap(): %s\n", strerror(errno));
> +
>  	return p;
>  }
>  
> @@ -499,7 +463,7 @@ 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...\n", msg);
>  
>  	/*
>  	 * Prevent khugepaged interference and tests that MADV_COLLAPSE
> @@ -526,10 +490,9 @@ 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);
>  }
>  
> @@ -541,23 +504,20 @@ 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...\n", msg);
>  	while (timeout--) {
>  		if (ops->check_huge(p, nr_hpages))
>  			break;
>  		if (thp_read_num("khugepaged/full_scans") >= full_scans)
>  			break;
> -		printf(".");
>  		usleep(TICK);
>  	}
>  
> @@ -623,7 +583,7 @@ 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...\n");
>  	if (check_huge_anon(p, 1, hpage_pmd_size))
>  		success("OK");
>  	else
> @@ -632,7 +592,7 @@ 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...\n");
>  	if (check_huge_anon(p, 0, hpage_pmd_size))
>  		success("OK");
>  	else
> @@ -688,7 +648,7 @@ static void collapse_max_ptes_none(struct collapse_context *c, struct mem_ops *o
>  
>  	if (is_tmpfs(ops)) {
>  		/* shmem pages always in the page cache */
> -		printf("tmpfs...");
> +		ksft_print_msg("tmpfs...\n");
>  		skip("Skip");
>  		goto skip;
>  	}
> @@ -717,11 +677,10 @@ 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...\n");
> +	if (madvise(p, page_size, MADV_PAGEOUT))
> +		ksft_exit_fail_msg("madvise(MADV_PAGEOUT): %s\n", strerror(errno));
> +
>  	if (check_swap(p, page_size)) {
>  		success("OK");
>  	} else {
> @@ -744,11 +703,10 @@ 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...\n", max_ptes_swap + 1, hpage_pmd_nr);
> +	if (madvise(p, (max_ptes_swap + 1) * page_size, MADV_PAGEOUT))
> +		ksft_exit_fail_msg("madvise(MADV_PAGEOUT): %s\n", strerror(errno));
> +
>  	if (check_swap(p, (max_ptes_swap + 1) * page_size)) {
>  		success("OK");
>  	} else {
> @@ -762,12 +720,11 @@ 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...\n", 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_msg("madvise(MADV_PAGEOUT): %s\n", strerror(errno));
> +
>  		if (check_swap(p, max_ptes_swap * page_size)) {
>  			success("OK");
>  		} else {
> @@ -791,13 +748,13 @@ static void collapse_single_pte_entry_compound(struct collapse_context *c, struc
>  
>  	if (is_tmpfs(ops)) {
>  		/* MADV_DONTNEED won't evict tmpfs pages */
> -		printf("tmpfs...");
> +		ksft_print_msg("tmpfs...\n");
>  		skip("Skip");
>  		goto skip;
>  	}
>  
>  	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...\n");
>  	madvise(p + page_size, hpage_pmd_size - page_size, MADV_DONTNEED);
>  	if (ops->check_huge(p, 0))
>  		success("OK");
> @@ -816,7 +773,7 @@ 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...\n");
>  	madvise(p, page_size, MADV_NOHUGEPAGE);
>  	madvise(p, hpage_pmd_size, MADV_NOHUGEPAGE);
>  	if (ops->check_huge(p, 0))
> @@ -837,15 +794,14 @@ static void collapse_compound_extreme(struct collapse_context *c, struct mem_ops
>  
>  	p = ops->setup_area(1);
>  	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);
> +		ksft_print_msg("\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");
> +
>  		madvise(BASE_ADDR, hpage_pmd_size, MADV_NOHUGEPAGE);
>  
>  		p = mremap(BASE_ADDR - i * page_size,
> @@ -853,22 +809,20 @@ 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_msg("mremap+unmap: %s\n", strerror(errno));
>  
>  		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_msg("mremap+alloc: %s\n", strerror(errno));
>  	}
>  
> +	ksft_print_msg("\n");
> +
>  	ops->cleanup_area(BASE_ADDR, hpage_pmd_size);
>  	ops->fault(p, 0, hpage_pmd_size);
>  	if (!ops->check_huge(p, 1))
> @@ -890,23 +844,19 @@ 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...\n");
>  	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()...\n");
>  	if (!fork()) {
>  		/* Do not touch settings on child exit */
>  		skip_settings_restore = true;
> -		exit_status = 0;
>  
> -		if (ops->check_huge(p, 0))
> -			success("OK");
> -		else
> -			fail("Fail");
> +		ksft_test_result(ops->check_huge(p, 0), "%s: child\n", __func__);
>  
>  		ops->fault(p, page_size, 2 * page_size);
>  		c->collapse("Collapse PTE table with single page shared with parent process",
> @@ -914,13 +864,13 @@ static void collapse_fork(struct collapse_context *c, struct mem_ops *ops)
>  
>  		validate_memory(p, 0, page_size);
>  		ops->cleanup_area(p, hpage_pmd_size);
> -		exit(exit_status);
> +		exit(0);
>  	}
>  
>  	wait(&wstatus);
> -	exit_status += WEXITSTATUS(wstatus);
> +//	exit_status += WEXITSTATUS(wstatus);
Remove this line

>  
> -	printf("Check if parent still has small page...");
> +	ksft_print_msg("Check if parent still has small page...\n");
>  	if (ops->check_huge(p, 0))
>  		success("OK");
>  	else
> @@ -935,18 +885,14 @@ 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()...\n");
>  	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");
> +		ksft_test_result(ops->check_huge(p, 1), "%s: child\n", __func__);
>  
> -		printf("Split huge page PMD in child process...");
> +		ksft_print_msg("Split huge page PMD in child process...\n");
>  		madvise(p, page_size, MADV_NOHUGEPAGE);
>  		madvise(p, hpage_pmd_size, MADV_NOHUGEPAGE);
>  		if (ops->check_huge(p, 0))
> @@ -963,13 +909,13 @@ static void collapse_fork_compound(struct collapse_context *c, struct mem_ops *o
>  
>  		validate_memory(p, 0, hpage_pmd_size);
>  		ops->cleanup_area(p, hpage_pmd_size);
> -		exit(exit_status);
> +		exit(0);
>  	}
>  
>  	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...\n");
>  	if (ops->check_huge(p, 1))
>  		success("OK");
>  	else
> @@ -985,19 +931,15 @@ 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()...\n");
>  	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");
> +		ksft_test_result(ops->check_huge(p, 1), "%s: child\n", __func__);
>  
> -		printf("Trigger CoW on page %d of %d...",
> -				hpage_pmd_nr - max_ptes_shared - 1, hpage_pmd_nr);
> +		ksft_print_msg("Trigger CoW on page %d of %d...\n",
> +			       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))
>  			success("OK");
> @@ -1008,8 +950,8 @@ 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...",
> -			       hpage_pmd_nr - max_ptes_shared, hpage_pmd_nr);
> +			ksft_print_msg("Trigger CoW on page %d of %d...\n",
> +				       hpage_pmd_nr - max_ptes_shared, hpage_pmd_nr);
>  			ops->fault(p, 0, (hpage_pmd_nr - max_ptes_shared) *
>  				    page_size);
>  			if (ops->check_huge(p, 0))
> @@ -1023,13 +965,13 @@ static void collapse_max_ptes_shared(struct collapse_context *c, struct mem_ops
>  
>  		validate_memory(p, 0, hpage_pmd_size);
>  		ops->cleanup_area(p, hpage_pmd_size);
> -		exit(exit_status);
> +		exit(0);
>  	}
>  
>  	wait(&wstatus);
> -	exit_status += WEXITSTATUS(wstatus);
> +//	exit_status += WEXITSTATUS(wstatus);
Remove this line

>  
> -	printf("Check if parent still has huge page...");
> +	ksft_print_msg("Check if parent still has huge page...\n");
>  	if (ops->check_huge(p, 1))
>  		success("OK");
>  	else
> @@ -1083,20 +1025,19 @@ static void madvise_retracted_page_tables(struct collapse_context *c,
>  
>  static void usage(void)
>  {
> -	fprintf(stderr, "\nUsage: ./khugepaged [OPTIONS] <test type> [dir]\n\n");
> -	fprintf(stderr, "\t<test type>\t: <context>:<mem_type>\n");
> -	fprintf(stderr, "\t<context>\t: [all|khugepaged|madvise]\n");
> -	fprintf(stderr, "\t<mem_type>\t: [all|anon|file|shmem]\n");
> -	fprintf(stderr, "\n\t\"file,all\" mem_type requires [dir] argument\n");
> -	fprintf(stderr, "\n\t\"file,all\" mem_type requires kernel built with\n");
> -	fprintf(stderr,	"\tCONFIG_READ_ONLY_THP_FOR_FS=y\n");
> -	fprintf(stderr, "\n\tif [dir] is a (sub)directory of a tmpfs mount, tmpfs must be\n");
> -	fprintf(stderr,	"\tmounted with huge=madvise option for khugepaged tests to work\n");
> -	fprintf(stderr,	"\n\tSupported Options:\n");
> -	fprintf(stderr,	"\t\t-h: This help message.\n");
> -	fprintf(stderr,	"\t\t-s: mTHP size, expressed as page order.\n");
> -	fprintf(stderr,	"\t\t    Defaults to 0. Use this size for anon allocations.\n");
> -	exit(1);
> +	ksft_print_msg("\nUsage: ./khugepaged [OPTIONS] <test type> [dir]\n\n");
> +	ksft_print_msg("\t<test type>\t: <context>:<mem_type>\n");
> +	ksft_print_msg("\t<context>\t: [all|khugepaged|madvise]\n");
> +	ksft_print_msg("\t<mem_type>\t: [all|anon|file|shmem]\n");
> +	ksft_print_msg("\n\t\"file,all\" mem_type requires [dir] argument\n");
> +	ksft_print_msg("\n\t\"file,all\" mem_type requires kernel built with\n");
> +	ksft_print_msg("\tCONFIG_READ_ONLY_THP_FOR_FS=y\n");
> +	ksft_print_msg("\n\tif [dir] is a (sub)directory of a tmpfs mount, tmpfs must be\n");
> +	ksft_print_msg("\tmounted with huge=madvise option for khugepaged tests to work\n");
> +	ksft_print_msg("\n\tSupported Options:\n");
> +	ksft_print_msg("\t\t-h: This help message.\n");
> +	ksft_print_msg("\t\t-s: mTHP size, expressed as page order.\n");
> +	ksft_exit_fail_msg("\t\t    Defaults to 0. Use this size for anon allocations.\n");
>  }
>  
>  static void parse_test_type(int argc, char **argv)
> @@ -1190,16 +1131,17 @@ int main(int argc, char **argv)
>  		.read_ahead_kb = 0,
>  	};
>  
> +	ksft_print_header();
> +	ksft_set_plan(65);
> +
>  	parse_test_type(argc, argv);
>  
>  	setbuf(stdout, NULL);
>  
>  	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);
>  
> @@ -1217,7 +1159,7 @@ int main(int argc, char **argv)
>  
>  #define TEST(t, c, o) do { \
>  	if (c && o) { \
> -		printf("\nRun test: " #t " (%s:%s)\n", c->name, o->name); \
> +		ksft_print_msg("Run test: " #t " (%s:%s)\n", c->name, o->name); \
>  		t(c, o); \
>  	} \
>  	} while (0)
> @@ -1281,5 +1223,5 @@ int main(int argc, char **argv)
>  	TEST(madvise_retracted_page_tables, madvise_context, file_ops);
>  	TEST(madvise_retracted_page_tables, madvise_context, shmem_ops);
>  
> -	restore_settings(0);
> +	ksft_finished();
>  }