Commit acd7ccb284b8 ("mm: shmem: add large folio support for tmpfs")
changes huge=always to allocate THP/mTHP based on write size and
split_huge_page_test does not write PMD size data, so file-back THP is not
created during the test.
Set /sys/kernel/mm/transparent_hugepage/shmem_enabled to "force" to force
THP allocation.
Signed-off-by: Zi Yan <ziy@xxxxxxxxxx>
---
.../selftests/mm/split_huge_page_test.c | 47 +++++++++++++++++--
1 file changed, 43 insertions(+), 4 deletions(-)
diff --git a/tools/testing/selftests/mm/split_huge_page_test.c b/tools/testing/selftests/mm/split_huge_page_test.c
index 3f353f3d070f..eccaa347140b 100644
--- a/tools/testing/selftests/mm/split_huge_page_test.c
+++ b/tools/testing/selftests/mm/split_huge_page_test.c
@@ -264,15 +264,46 @@ void split_pte_mapped_thp(void)
void split_file_backed_thp(void)
{
int status;
- int fd;
- ssize_t num_written;
+ 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];
+ char testfile[INPUT_MAX], sysctl_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;
ksft_print_msg("Please enable pr_debug in split_huge_pages_in_file() for more info.\n");
+ shmem_sysctl_fd = open(shmem_sysctl, O_RDWR);
+ if (shmem_sysctl_fd == -1) {
+ ksft_perror("cannot open shmem sysctl");
+ goto out;
+ }
+
+ num_read = read(shmem_sysctl_fd, sysctl_buf, INPUT_MAX);
+ if (num_read < 1) {
+ ksft_perror("Failed to read shmem sysctl");
+ goto out;
+ }
+
+ opt1 = strchr(sysctl_buf, '[');
+ opt2 = strchr(sysctl_buf, ']');
+ if (!opt1 || !opt2) {
+ ksft_perror("cannot read shmem sysctl config");
+ goto out;
+ }
+
+ /* get existing shmem sysctl config into sysctl_buf */
+ strncpy(sysctl_buf, opt1 + 1, opt2 - opt1 - 1);
+ memset(sysctl_buf + (opt2 - opt1 - 1), 0, INPUT_MAX);
+
+ num_written = write(shmem_sysctl_fd, "force", sizeof("force"));
+ if (num_written < 1) {
+ ksft_perror("Fail to write force to shmem sysctl");
+ goto out;
+ }
+
status = mount("tmpfs", tmpfs_loc, "tmpfs", 0, "huge=always,size=4m");
if (status)
@@ -317,13 +348,21 @@ void split_file_backed_thp(void)
if (status)
ksft_exit_fail_msg("cannot remove tmp dir: %s\n", strerror(errno));
+ num_written = write(shmem_sysctl_fd, sysctl_buf, strlen(sysctl_buf) + 1);
+ if (num_written < 1)
+ ksft_perror("Fail to restore shmem sysctl");
+
ksft_print_msg("Please check dmesg for more information\n");
- ksft_test_result_pass("File-backed THP split test done\n");
+ ksft_test_result_pass("File-backed THP split to order %d test done\n", order);
return;
cleanup:
+ num_written = write(shmem_sysctl_fd, sysctl_buf, strlen(sysctl_buf) + 1);
+ if (num_written < 1)
+ ksft_perror("Fail to restore shmem sysctl");
umount(tmpfs_loc);
rmdir(tmpfs_loc);
+out:
ksft_exit_fail_msg("Error occurred\n");
}
--
2.45.2
