Re: [PATCH v7 0/7] selftests/mm: skip several tests when thp is not available

Andrew Morton
2026-03-30T19:25:09Z

On Mon, 30 Mar 2026 23:14:56 +0800 Chunyu Hu <chuhu@redhat.com> wrote:

> There are several tests requires transprarent hugepages, when run on thp
> disabled kernel such as realtime kernel, there will be false negative.
> Mark those tests as skip when thp is not available.

Thanks, I updated mm.git's mm-unstable branch to this version.

> Changes in v7:
> - patch 1 add reviewed-by from Lorenzo
> - patch 4 new patch to make ksft_exit_fail_perror variable length
> arguments
> - patch 5 change to use %.*s to print the buf when error happened
> Limit the buflen arg as 2 minimum. Check the error path (numwritten
> < 0).
> And use the ksft_exit_fail_perror to print the logs in error path

Here's how v7 altered mm.git.

tools/testing/selftests/kselftest.h | 21 ++++++++++++++++++---
tools/testing/selftests/mm/vm_util.c | 14 +++++++-------
2 files changed, 25 insertions(+), 10 deletions(-)

--- a/tools/testing/selftests/kselftest.h~b
+++ a/tools/testing/selftests/kselftest.h
@@ -43,7 +43,7 @@
* the program is aborting before finishing all tests):
*
* ksft_exit_fail_msg(fmt, ...);
- * ksft_exit_fail_perror(msg);
+ * ksft_exit_fail_perror(fmt, ...);
*
*/
#ifndef __KSELFTEST_H
@@ -417,9 +417,24 @@ static inline __noreturn __printf(1, 2)
exit(KSFT_FAIL);
}

-static inline __noreturn void ksft_exit_fail_perror(const char *msg)
+static inline __noreturn __printf(1, 2) void ksft_exit_fail_perror(const char *msg, ...)
{
- ksft_exit_fail_msg("%s: %s (%d)\n", msg, strerror(errno), errno);
+ va_list args;
+ char *buf = NULL;
+ int saved_errno = errno;
+
+ va_start(args, msg);
+ if (vasprintf(&buf, msg, args) == -1) {
+ va_end(args);
+ ksft_exit_fail_msg("vasprintf failed: %s (%d)\n", strerror(saved_errno),
+ saved_errno);
+ }
+ va_end(args);
+
+ errno = saved_errno;
+ ksft_exit_fail_msg("%s: %s (%d)\n", buf, strerror(errno), errno);
+
+ free(buf);
}

static inline __noreturn void ksft_exit_xfail(void)
--- a/tools/testing/selftests/mm/vm_util.c~b
+++ a/tools/testing/selftests/mm/vm_util.c
@@ -782,21 +782,21 @@ void write_file(const char *path, const
int fd, saved_errno;
ssize_t numwritten;

- if (buflen < 1)
+ if (buflen < 2)
ksft_exit_fail_msg("Incorrect buffer len: %zu\n", buflen);

fd = open(path, O_WRONLY);
if (fd == -1)
- ksft_exit_fail_msg("%s open failed: %s\n", path, strerror(errno));
+ ksft_exit_fail_perror("%s open failed", path);

numwritten = write(fd, buf, buflen - 1);
saved_errno = errno;
close(fd);
errno = saved_errno;
- if (numwritten < 1)
- ksft_exit_fail_msg("%s write(%s) failed: %s\n", path, buf,
- strerror(errno));
+ if (numwritten < 0)
+ ksft_exit_fail_perror("%s write(%.*s) failed", path, (int)(buflen - 1),
+ buf);
if (numwritten != buflen - 1)
- ksft_exit_fail_msg("%s write(%s) is truncated, expected %zu bytes, got %zd bytes\n",
- path, buf, buflen - 1, numwritten);
+ ksft_exit_fail_msg("%s write(%.*s) is truncated, expected %zu bytes, got %zd bytes\n",
+ path, (int)(buflen - 1), buf, buflen - 1, numwritten);
}
_