[PATCH 3/6] kselftests: timers: set-timer-lat: Tweak reporting when timer fires early

From: John Stultz
Date: Fri Aug 18 2017 - 14:52:31 EST


From: Greg Hackmann <ghackmann@xxxxxxxxxx>

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.

Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Miroslav Lichvar <mlichvar@xxxxxxxxxx>
Cc: Richard Cochran <richardcochran@xxxxxxxxx>
Cc: Prarit Bhargava <prarit@xxxxxxxxxx>
Cc: Stephen Boyd <stephen.boyd@xxxxxxxxxx>
Cc: Shuah Khan <shuah@xxxxxxxxxx>
Cc: linux-kselftest@xxxxxxxxxxxxxxx
Signed-off-by: Greg Hackmann <ghackmann@xxxxxxxxxx>
Signed-off-by: John Stultz <john.stultz@xxxxxxxxxx>
---
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 4fc98c5..10c2e18 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)
--
2.7.4