The following commit has been merged into the timers/core branch of tip:
Commit-ID: 263dda24fff0957f6b0a9abde2809122f7f0fad8
Gitweb: https://git.kernel.org/tip/263dda24fff0957f6b0a9abde2809122f7f0fad8
Author: Frederic Weisbecker <frederic@xxxxxxxxxx>
AuthorDate: Wed, 22 Feb 2023 15:46:49 +01:00
Committer: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
CommitterDate: Tue, 18 Apr 2023 16:35:13 +02:00
selftests/proc: Assert clock_gettime(CLOCK_BOOTTIME) VS /proc/uptime monotonicity
The first field of /proc/uptime relies on the CLOCK_BOOTTIME clock which
can also be fetched from clock_gettime() API.
Improve the test coverage while verifying the monotonicity of
CLOCK_BOOTTIME accross both interfaces.
Suggested-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Signed-off-by: Frederic Weisbecker <frederic@xxxxxxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20230222144649.624380-9-frederic@xxxxxxxxxx
---
tools/testing/selftests/proc/proc-uptime-001.c | 21 ++++++++++++----
tools/testing/selftests/proc/proc-uptime-002.c | 22 +++++++++++++----
tools/testing/selftests/proc/proc-uptime.h | 12 +++++++++-
3 files changed, 47 insertions(+), 8 deletions(-)
diff --git a/tools/testing/selftests/proc/proc-uptime-001.c b/tools/testing/selftests/proc/proc-uptime-001.c
index 35bddd9..f335eec 100644
--- a/tools/testing/selftests/proc/proc-uptime-001.c
+++ b/tools/testing/selftests/proc/proc-uptime-001.c
@@ -13,9 +13,9 @@
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
-// Test that boottime value in /proc/uptime increments monotonically.
-// We don't test idle time monotonicity due to broken iowait task
-// counting, cf: comment above get_cpu_idle_time_us()
+// Test that boottime value in /proc/uptime and CLOCK_BOOTTIME increment
+// monotonically. We don't test idle time monotonicity due to broken iowait
+// task counting, cf: comment above get_cpu_idle_time_us()
#undef NDEBUG
#include <assert.h>
#include <stdint.h>
@@ -27,7 +27,7 @@
int main(void)
{
- uint64_t start, u0, u1;
+ uint64_t start, u0, u1, c0, c1;
int fd;
fd = open("/proc/uptime", O_RDONLY);
@@ -35,10 +35,23 @@ int main(void)
u0 = proc_uptime(fd);
start = u0;
+ c0 = clock_boottime();
+
do {
u1 = proc_uptime(fd);
+ c1 = clock_boottime();
+
+ /* Is /proc/uptime monotonic ? */
assert(u1 >= u0);
+
+ /* Is CLOCK_BOOTTIME monotonic ? */
+ assert(c1 >= c0);
+
+ /* Is CLOCK_BOOTTIME VS /proc/uptime monotonic ? */
+ assert(c0 >= u0);
+
u0 = u1;
+ c0 = c1;
} while (u1 - start < 100);
return 0;
diff --git a/tools/testing/selftests/proc/proc-uptime-002.c b/tools/testing/selftests/proc/proc-uptime-002.c
index 7ad79d5..ae453da 100644
--- a/tools/testing/selftests/proc/proc-uptime-002.c
+++ b/tools/testing/selftests/proc/proc-uptime-002.c
@@ -13,9 +13,10 @@
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
-// Test that boottime value in /proc/uptime increments monotonically
-// while shifting across CPUs. We don't test idle time monotonicity
-// due to broken iowait task counting, cf: comment above get_cpu_idle_time_us()
+// Test that boottime value in /proc/uptime and CLOCK_BOOTTIME increment
+// monotonically while shifting across CPUs. We don't test idle time
+// monotonicity due to broken iowait task counting, cf: comment above
+// get_cpu_idle_time_us()
#undef NDEBUG
#include <assert.h>
#include <errno.h>
@@ -43,10 +44,10 @@ static inline int sys_sched_setaffinity(pid_t pid, unsigned int len, unsigned lo
int main(void)
{
+ uint64_t u0, u1, c0, c1;
unsigned int len;
unsigned long *m;
unsigned int cpu;
- uint64_t u0, u1;
int fd;
/* find out "nr_cpu_ids" */
@@ -62,6 +63,8 @@ int main(void)
assert(fd >= 0);
u0 = proc_uptime(fd);
+ c0 = clock_boottime();
+
for (cpu = 0; cpu < len * 8; cpu++) {
memset(m, 0, len);
m[cpu / (8 * sizeof(unsigned long))] |= 1UL << (cpu % (8 * sizeof(unsigned long)));
@@ -70,8 +73,19 @@ int main(void)
sys_sched_setaffinity(0, len, m);
u1 = proc_uptime(fd);
+ c1 = clock_boottime();
+
+ /* Is /proc/uptime monotonic ? */
assert(u1 >= u0);
+
+ /* Is CLOCK_BOOTTIME monotonic ? */
+ assert(c1 >= c0);
+
+ /* Is CLOCK_BOOTTIME VS /proc/uptime monotonic ? */
+ assert(c0 >= u0);
+
u0 = u1;
+ c0 = c1;
}
return 0;
diff --git a/tools/testing/selftests/proc/proc-uptime.h b/tools/testing/selftests/proc/proc-uptime.h
index ca55abe..730cce4 100644
--- a/tools/testing/selftests/proc/proc-uptime.h
+++ b/tools/testing/selftests/proc/proc-uptime.h
@@ -19,9 +19,21 @@
#include <string.h>
#include <stdlib.h>
#include <unistd.h>
+#include <time.h>
#include "proc.h"
+static uint64_t clock_boottime(void)
+{
+ struct timespec ts;
+ int err;
+
+ err = clock_gettime(CLOCK_BOOTTIME, &ts);
+ assert(err >= 0);
+
+ return (ts.tv_sec * 100) + (ts.tv_nsec / 10000000);
+}
+
static uint64_t proc_uptime(int fd)
{
uint64_t val1, val2;
|