Re: [PATCH v5 03/10] selftests/mm: test splitting file-backed THP to any lower order.

On 2025/1/17 05:10, Zi Yan wrote:

Now split_huge_page*() supports shmem THP split to any lower order. Test it.

The test now reads file content out after split to check if the split corrupts the file data.

Signed-off-by: Zi Yan ziy@nvidia.com

LGTM. Reviewed-by: Baolin Wang baolin.wang@linux.alibaba.com Tested-by: Baolin Wang baolin.wang@linux.alibaba.com

---

.../selftests/mm/split_huge_page_test.c | 30 ++++++++++++++----- 1 file changed, 23 insertions(+), 7 deletions(-)

diff --git a/tools/testing/selftests/mm/split_huge_page_test.c b/tools/testing/selftests/mm/split_huge_page_test.c index eccaa347140b..766c1f3a1d78 100644 --- a/tools/testing/selftests/mm/split_huge_page_test.c +++ b/tools/testing/selftests/mm/split_huge_page_test.c @@ -261,14 +261,16 @@ void split_pte_mapped_thp(void) close(kpageflags_fd); } -void split_file_backed_thp(void) +void split_file_backed_thp(int order) { int status; int fd, shmem_sysctl_fd; ssize_t num_written, num_read; char tmpfs_template[] = "/tmp/thp_split_XXXXXX"; const char *tmpfs_loc = mkdtemp(tmpfs_template);

• char testfile[INPUT_MAX], sysctl_buf[INPUT_MAX] = {0};

• char testfile[INPUT_MAX];
• char sysctl_buf[INPUT_MAX] = {0};
• char file_buf[INPUT_MAX] = {0}; uint64_t pgoff_start = 0, pgoff_end = 1024; const char *shmem_sysctl = "/sys/kernel/mm/transparent_hugepage/shmem_enabled"; char *opt1, *opt2;

@@ -314,7 +316,7 @@ void split_file_backed_thp(void) ksft_exit_fail_msg("Fail to create file-backed THP split testing file\n"); }

• fd = open(testfile, O_CREAT|O_WRONLY, 0664);

• fd = open(testfile, O_CREAT|O_RDWR, 0664); if (fd == -1) { ksft_perror("Cannot open testing file"); goto cleanup;

@@ -322,7 +324,6 @@ void split_file_backed_thp(void) /* write something to the file, so a file-backed THP can be allocated */ num_written = write(fd, tmpfs_loc, strlen(tmpfs_loc) + 1);

• close(fd);

if (num_written < 1) { ksft_perror("Fail to write data to testing file"); @@ -330,8 +331,22 @@ void split_file_backed_thp(void) } /* split the file-backed THP */

• write_debugfs(PATH_FMT, testfile, pgoff_start, pgoff_end, 0);

• write_debugfs(PATH_FMT, testfile, pgoff_start, pgoff_end, order);
• /* check file content after split */
• num_read = lseek(fd, 0, SEEK_SET);
• if (num_read == -1) {

• ksft_perror("Cannot lseek file");
  

• goto cleanup;
  

• }

• num_read = read(fd, file_buf, num_written);
• if (num_read < 1 || strncmp(file_buf, tmpfs_loc, num_read)) {

• ksft_print_msg("File content changed, origin: %s, now: %s\n", tmpfs_loc, file_buf);
  

• goto cleanup;
  

• }
• close(fd); status = unlink(testfile); if (status) { ksft_perror("Cannot remove testing file");

@@ -520,7 +535,7 @@ int main(int argc, char **argv) if (argc > 1) optional_xfs_path = argv[1];

• ksft_set_plan(1+8+2+9);

• ksft_set_plan(1+8+1+9+9);

pagesize = getpagesize(); pageshift = ffs(pagesize) - 1; @@ -537,7 +552,8 @@ int main(int argc, char **argv) split_pmd_thp_to_order(i); split_pte_mapped_thp();

• split_file_backed_thp();

• for (i = 0; i < 9; i++)

• split_file_backed_thp(i);
  

created_tmp = prepare_thp_fs(optional_xfs_path, fs_loc_template, &fs_loc);