This patchset expands set-timer-lat to cover one-shot timers. This is
inspired by a recent regression in the -stable tree, which caused one-shot
alarm timers to repeat at a 1 ns interval.
The first patch adjusts how early-firing timers are reported, so faulty
kernels won't cause the test to spam the console with failure messages.
The second patch actually adds the one-shot testcases.
Greg Hackmann (2):
kselftests: set-timer-lat: tweak reporting when timer fires early
kselftests: set-timer-lat: add one-shot timer test cases
tools/testing/selftests/timers/set-timer-lat.c | 103 +++++++++++++++++++++----
1 file changed, 90 insertions(+), 13 deletions(-)
--
2.14.0.rc0.400.g1c36432dff-goog
These testcases are motivated by a recent alarmtimer regression, which
caused one-shot CLOCK_{BOOTTIME,REALTIME}_ALARM timers to become
periodic timers.
The new testcases are very similar to the existing testcases for
repeating timers. But rather than waiting for 5 alarms, they wait for 5
seconds and verify that the alarm fired exactly once.
Signed-off-by: Greg Hackmann <[email protected]>
---
tools/testing/selftests/timers/set-timer-lat.c | 86 ++++++++++++++++++++++----
1 file changed, 73 insertions(+), 13 deletions(-)
diff --git a/tools/testing/selftests/timers/set-timer-lat.c b/tools/testing/selftests/timers/set-timer-lat.c
index 10c2e18737c0..15434da23b04 100644
--- a/tools/testing/selftests/timers/set-timer-lat.c
+++ b/tools/testing/selftests/timers/set-timer-lat.c
@@ -20,6 +20,7 @@
*/
+#include <errno.h>
#include <stdio.h>
#include <unistd.h>
#include <time.h>
@@ -122,17 +123,17 @@ void sigalarm(int signo)
max_latency_ns = delta_ns;
}
-void describe_timer(int flags)
+void describe_timer(int flags, int interval)
{
- printf("%-22s %s ",
+ printf("%-22s %s %s ",
clockstring(clock_id),
- flags ? "ABSTIME":"RELTIME");
+ flags ? "ABSTIME":"RELTIME",
+ interval ? "PERIODIC":"ONE-SHOT");
}
-int do_timer(int clock_id, int flags)
+int setup_timer(int clock_id, int flags, int interval, timer_t *tm1)
{
struct sigevent se;
- timer_t tm1;
struct itimerspec its1, its2;
int err;
@@ -146,7 +147,7 @@ int do_timer(int clock_id, int flags)
alarmcount = 0;
timer_fired_early = 0;
- err = timer_create(clock_id, &se, &tm1);
+ err = timer_create(clock_id, &se, tm1);
if (err) {
if ((clock_id == CLOCK_REALTIME_ALARM) ||
(clock_id == CLOCK_BOOTTIME_ALARM)) {
@@ -167,19 +168,23 @@ int do_timer(int clock_id, int flags)
its1.it_value.tv_sec = TIMER_SECS;
its1.it_value.tv_nsec = 0;
}
- its1.it_interval.tv_sec = TIMER_SECS;
+ its1.it_interval.tv_sec = interval;
its1.it_interval.tv_nsec = 0;
- err = timer_settime(tm1, flags, &its1, &its2);
+ err = timer_settime(*tm1, flags, &its1, &its2);
if (err) {
printf("%s - timer_settime() failed\n", clockstring(clock_id));
return -1;
}
- while (alarmcount < 5)
- sleep(1);
+ return 0;
+}
- describe_timer(flags);
+int check_timer_latency(int flags, int interval)
+{
+ int err = 0;
+
+ describe_timer(flags, interval);
printf("timer fired early: %7d : ", timer_fired_early);
if (!timer_fired_early) {
printf("[OK]\n");
@@ -188,10 +193,9 @@ int do_timer(int clock_id, int flags)
err = -1;
}
- describe_timer(flags);
+ describe_timer(flags, interval);
printf("max latency: %10lld ns : ", max_latency_ns);
- timer_delete(tm1);
if (max_latency_ns < UNRESONABLE_LATENCY) {
printf("[OK]\n");
} else {
@@ -201,6 +205,60 @@ int do_timer(int clock_id, int flags)
return err;
}
+int check_alarmcount(int flags, int interval)
+{
+ describe_timer(flags, interval);
+ printf("count: %19d : ", alarmcount);
+ if (alarmcount == 1) {
+ printf("[OK]\n");
+ return 0;
+ }
+ printf("[FAILED]\n");
+ return -1;
+}
+
+int do_timer(int clock_id, int flags)
+{
+ timer_t tm1;
+ const int interval = TIMER_SECS;
+ int err;
+
+ err = setup_timer(clock_id, flags, interval, &tm1);
+ if (err)
+ return err;
+
+ while (alarmcount < 5)
+ sleep(1);
+
+ timer_delete(tm1);
+ return check_timer_latency(flags, interval);
+}
+
+int do_timer_oneshot(int clock_id, int flags)
+{
+ timer_t tm1;
+ const int interval = 0;
+ struct timeval timeout;
+ fd_set fds;
+ int err;
+
+ err = setup_timer(clock_id, flags, interval, &tm1);
+ if (err)
+ return err;
+
+ memset(&timeout, 0, sizeof(timeout));
+ timeout.tv_sec = 5;
+ FD_ZERO(&fds);
+ do {
+ err = select(FD_SETSIZE, &fds, NULL, NULL, &timeout);
+ } while (err == -1 && errno == EINTR);
+
+ timer_delete(tm1);
+ err = check_timer_latency(flags, interval);
+ err |= check_alarmcount(flags, interval);
+ return err;
+}
+
int main(void)
{
struct sigaction act;
@@ -226,6 +284,8 @@ int main(void)
ret |= do_timer(clock_id, TIMER_ABSTIME);
ret |= do_timer(clock_id, 0);
+ ret |= do_timer_oneshot(clock_id, TIMER_ABSTIME);
+ ret |= do_timer_oneshot(clock_id, 0);
}
if (ret)
return ksft_exit_fail();
--
2.14.0.rc0.400.g1c36432dff-goog
Rather than printing an error inside the alarm signal handler, set a
flag that we check later. This keeps the test from spamming the console
every time the alarm fires early. It also fixes the test exiting with
error code 0 if this was the only test failure.
Signed-off-by: Greg Hackmann <[email protected]>
---
tools/testing/selftests/timers/set-timer-lat.c | 33 +++++++++++++++++++-------
1 file changed, 25 insertions(+), 8 deletions(-)
diff --git a/tools/testing/selftests/timers/set-timer-lat.c b/tools/testing/selftests/timers/set-timer-lat.c
index 4fc98c5b0899..10c2e18737c0 100644
--- a/tools/testing/selftests/timers/set-timer-lat.c
+++ b/tools/testing/selftests/timers/set-timer-lat.c
@@ -63,6 +63,7 @@ int alarmcount;
int clock_id;
struct timespec start_time;
long long max_latency_ns;
+int timer_fired_early;
char *clockstring(int clockid)
{
@@ -115,12 +116,19 @@ void sigalarm(int signo)
delta_ns -= NSEC_PER_SEC * TIMER_SECS * alarmcount;
if (delta_ns < 0)
- printf("%s timer fired early: FAIL\n", clockstring(clock_id));
+ timer_fired_early = 1;
if (delta_ns > max_latency_ns)
max_latency_ns = delta_ns;
}
+void describe_timer(int flags)
+{
+ printf("%-22s %s ",
+ clockstring(clock_id),
+ flags ? "ABSTIME":"RELTIME");
+}
+
int do_timer(int clock_id, int flags)
{
struct sigevent se;
@@ -136,6 +144,7 @@ int do_timer(int clock_id, int flags)
max_latency_ns = 0;
alarmcount = 0;
+ timer_fired_early = 0;
err = timer_create(clock_id, &se, &tm1);
if (err) {
@@ -170,18 +179,26 @@ int do_timer(int clock_id, int flags)
while (alarmcount < 5)
sleep(1);
- printf("%-22s %s max latency: %10lld ns : ",
- clockstring(clock_id),
- flags ? "ABSTIME":"RELTIME",
- max_latency_ns);
+ describe_timer(flags);
+ printf("timer fired early: %7d : ", timer_fired_early);
+ if (!timer_fired_early) {
+ printf("[OK]\n");
+ } else {
+ printf("[FAILED]\n");
+ err = -1;
+ }
+
+ describe_timer(flags);
+ printf("max latency: %10lld ns : ", max_latency_ns);
timer_delete(tm1);
if (max_latency_ns < UNRESONABLE_LATENCY) {
printf("[OK]\n");
- return 0;
+ } else {
+ printf("[FAILED]\n");
+ err = -1;
}
- printf("[FAILED]\n");
- return -1;
+ return err;
}
int main(void)
--
2.14.0.rc0.400.g1c36432dff-goog