diff options
Diffstat (limited to 'kernel/tools/testing/selftests/timers/set-timer-lat.c')
| -rw-r--r-- | kernel/tools/testing/selftests/timers/set-timer-lat.c | 216 |
1 files changed, 216 insertions, 0 deletions
diff --git a/kernel/tools/testing/selftests/timers/set-timer-lat.c b/kernel/tools/testing/selftests/timers/set-timer-lat.c new file mode 100644 index 000000000..4fc98c5b0 --- /dev/null +++ b/kernel/tools/testing/selftests/timers/set-timer-lat.c @@ -0,0 +1,216 @@ +/* set_timer latency test + * John Stultz (john.stultz@linaro.org) + * (C) Copyright Linaro 2014 + * Licensed under the GPLv2 + * + * This test makes sure the set_timer api is correct + * + * To build: + * $ gcc set-timer-lat.c -o set-timer-lat -lrt + * + * This program is free software: you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation, either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ + + +#include <stdio.h> +#include <unistd.h> +#include <time.h> +#include <string.h> +#include <signal.h> +#include <stdlib.h> +#include <pthread.h> +#ifdef KTEST +#include "../kselftest.h" +#else +static inline int ksft_exit_pass(void) +{ + exit(0); +} +static inline int ksft_exit_fail(void) +{ + exit(1); +} +#endif + +#define CLOCK_REALTIME 0 +#define CLOCK_MONOTONIC 1 +#define CLOCK_PROCESS_CPUTIME_ID 2 +#define CLOCK_THREAD_CPUTIME_ID 3 +#define CLOCK_MONOTONIC_RAW 4 +#define CLOCK_REALTIME_COARSE 5 +#define CLOCK_MONOTONIC_COARSE 6 +#define CLOCK_BOOTTIME 7 +#define CLOCK_REALTIME_ALARM 8 +#define CLOCK_BOOTTIME_ALARM 9 +#define CLOCK_HWSPECIFIC 10 +#define CLOCK_TAI 11 +#define NR_CLOCKIDS 12 + + +#define NSEC_PER_SEC 1000000000ULL +#define UNRESONABLE_LATENCY 40000000 /* 40ms in nanosecs */ + +#define TIMER_SECS 1 +int alarmcount; +int clock_id; +struct timespec start_time; +long long max_latency_ns; + +char *clockstring(int clockid) +{ + switch (clockid) { + case CLOCK_REALTIME: + return "CLOCK_REALTIME"; + case CLOCK_MONOTONIC: + return "CLOCK_MONOTONIC"; + case CLOCK_PROCESS_CPUTIME_ID: + return "CLOCK_PROCESS_CPUTIME_ID"; + case CLOCK_THREAD_CPUTIME_ID: + return "CLOCK_THREAD_CPUTIME_ID"; + case CLOCK_MONOTONIC_RAW: + return "CLOCK_MONOTONIC_RAW"; + case CLOCK_REALTIME_COARSE: + return "CLOCK_REALTIME_COARSE"; + case CLOCK_MONOTONIC_COARSE: + return "CLOCK_MONOTONIC_COARSE"; + case CLOCK_BOOTTIME: + return "CLOCK_BOOTTIME"; + case CLOCK_REALTIME_ALARM: + return "CLOCK_REALTIME_ALARM"; + case CLOCK_BOOTTIME_ALARM: + return "CLOCK_BOOTTIME_ALARM"; + case CLOCK_TAI: + return "CLOCK_TAI"; + }; + return "UNKNOWN_CLOCKID"; +} + + +long long timespec_sub(struct timespec a, struct timespec b) +{ + long long ret = NSEC_PER_SEC * b.tv_sec + b.tv_nsec; + + ret -= NSEC_PER_SEC * a.tv_sec + a.tv_nsec; + return ret; +} + + +void sigalarm(int signo) +{ + long long delta_ns; + struct timespec ts; + + clock_gettime(clock_id, &ts); + alarmcount++; + + delta_ns = timespec_sub(start_time, ts); + delta_ns -= NSEC_PER_SEC * TIMER_SECS * alarmcount; + + if (delta_ns < 0) + printf("%s timer fired early: FAIL\n", clockstring(clock_id)); + + if (delta_ns > max_latency_ns) + max_latency_ns = delta_ns; +} + +int do_timer(int clock_id, int flags) +{ + struct sigevent se; + timer_t tm1; + struct itimerspec its1, its2; + int err; + + /* Set up timer: */ + memset(&se, 0, sizeof(se)); + se.sigev_notify = SIGEV_SIGNAL; + se.sigev_signo = SIGRTMAX; + se.sigev_value.sival_int = 0; + + max_latency_ns = 0; + alarmcount = 0; + + err = timer_create(clock_id, &se, &tm1); + if (err) { + if ((clock_id == CLOCK_REALTIME_ALARM) || + (clock_id == CLOCK_BOOTTIME_ALARM)) { + printf("%-22s %s missing CAP_WAKE_ALARM? : [UNSUPPORTED]\n", + clockstring(clock_id), + flags ? "ABSTIME":"RELTIME"); + return 0; + } + printf("%s - timer_create() failed\n", clockstring(clock_id)); + return -1; + } + + clock_gettime(clock_id, &start_time); + if (flags) { + its1.it_value = start_time; + its1.it_value.tv_sec += TIMER_SECS; + } else { + its1.it_value.tv_sec = TIMER_SECS; + its1.it_value.tv_nsec = 0; + } + its1.it_interval.tv_sec = TIMER_SECS; + its1.it_interval.tv_nsec = 0; + + 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); + + printf("%-22s %s max latency: %10lld ns : ", + clockstring(clock_id), + flags ? "ABSTIME":"RELTIME", + max_latency_ns); + + timer_delete(tm1); + if (max_latency_ns < UNRESONABLE_LATENCY) { + printf("[OK]\n"); + return 0; + } + printf("[FAILED]\n"); + return -1; +} + +int main(void) +{ + struct sigaction act; + int signum = SIGRTMAX; + int ret = 0; + + /* Set up signal handler: */ + sigfillset(&act.sa_mask); + act.sa_flags = 0; + act.sa_handler = sigalarm; + sigaction(signum, &act, NULL); + + printf("Setting timers for every %i seconds\n", TIMER_SECS); + for (clock_id = 0; clock_id < NR_CLOCKIDS; clock_id++) { + + if ((clock_id == CLOCK_PROCESS_CPUTIME_ID) || + (clock_id == CLOCK_THREAD_CPUTIME_ID) || + (clock_id == CLOCK_MONOTONIC_RAW) || + (clock_id == CLOCK_REALTIME_COARSE) || + (clock_id == CLOCK_MONOTONIC_COARSE) || + (clock_id == CLOCK_HWSPECIFIC)) + continue; + + ret |= do_timer(clock_id, TIMER_ABSTIME); + ret |= do_timer(clock_id, 0); + } + if (ret) + return ksft_exit_fail(); + return ksft_exit_pass(); +} |