284 lines · c
1/* set_timer latency test2 * John Stultz (john.stultz@linaro.org)3 * (C) Copyright Linaro 20144 * Licensed under the GPLv25 *6 * This test makes sure the set_timer api is correct7 *8 * To build:9 * $ gcc set-timer-lat.c -o set-timer-lat -lrt10 *11 * This program is free software: you can redistribute it and/or modify12 * it under the terms of the GNU General Public License as published by13 * the Free Software Foundation, either version 2 of the License, or14 * (at your option) any later version.15 *16 * This program is distributed in the hope that it will be useful,17 * but WITHOUT ANY WARRANTY; without even the implied warranty of18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the19 * GNU General Public License for more details.20 */21 22 23#include <errno.h>24#include <stdio.h>25#include <unistd.h>26#include <time.h>27#include <string.h>28#include <signal.h>29#include <stdlib.h>30#include <pthread.h>31#include "../kselftest.h"32 33#define CLOCK_REALTIME 034#define CLOCK_MONOTONIC 135#define CLOCK_PROCESS_CPUTIME_ID 236#define CLOCK_THREAD_CPUTIME_ID 337#define CLOCK_MONOTONIC_RAW 438#define CLOCK_REALTIME_COARSE 539#define CLOCK_MONOTONIC_COARSE 640#define CLOCK_BOOTTIME 741#define CLOCK_REALTIME_ALARM 842#define CLOCK_BOOTTIME_ALARM 943#define CLOCK_HWSPECIFIC 1044#define CLOCK_TAI 1145#define NR_CLOCKIDS 1246 47 48#define NSEC_PER_SEC 1000000000ULL49#define UNRESONABLE_LATENCY 40000000 /* 40ms in nanosecs */50 51#define TIMER_SECS 152int alarmcount;53int clock_id;54struct timespec start_time;55long long max_latency_ns;56int timer_fired_early;57 58char *clockstring(int clockid)59{60 switch (clockid) {61 case CLOCK_REALTIME:62 return "CLOCK_REALTIME";63 case CLOCK_MONOTONIC:64 return "CLOCK_MONOTONIC";65 case CLOCK_PROCESS_CPUTIME_ID:66 return "CLOCK_PROCESS_CPUTIME_ID";67 case CLOCK_THREAD_CPUTIME_ID:68 return "CLOCK_THREAD_CPUTIME_ID";69 case CLOCK_MONOTONIC_RAW:70 return "CLOCK_MONOTONIC_RAW";71 case CLOCK_REALTIME_COARSE:72 return "CLOCK_REALTIME_COARSE";73 case CLOCK_MONOTONIC_COARSE:74 return "CLOCK_MONOTONIC_COARSE";75 case CLOCK_BOOTTIME:76 return "CLOCK_BOOTTIME";77 case CLOCK_REALTIME_ALARM:78 return "CLOCK_REALTIME_ALARM";79 case CLOCK_BOOTTIME_ALARM:80 return "CLOCK_BOOTTIME_ALARM";81 case CLOCK_TAI:82 return "CLOCK_TAI";83 };84 return "UNKNOWN_CLOCKID";85}86 87 88long long timespec_sub(struct timespec a, struct timespec b)89{90 long long ret = NSEC_PER_SEC * b.tv_sec + b.tv_nsec;91 92 ret -= NSEC_PER_SEC * a.tv_sec + a.tv_nsec;93 return ret;94}95 96 97void sigalarm(int signo)98{99 long long delta_ns;100 struct timespec ts;101 102 clock_gettime(clock_id, &ts);103 alarmcount++;104 105 delta_ns = timespec_sub(start_time, ts);106 delta_ns -= NSEC_PER_SEC * TIMER_SECS * alarmcount;107 108 if (delta_ns < 0)109 timer_fired_early = 1;110 111 if (delta_ns > max_latency_ns)112 max_latency_ns = delta_ns;113}114 115void describe_timer(int flags, int interval)116{117 printf("%-22s %s %s ",118 clockstring(clock_id),119 flags ? "ABSTIME":"RELTIME",120 interval ? "PERIODIC":"ONE-SHOT");121}122 123int setup_timer(int clock_id, int flags, int interval, timer_t *tm1)124{125 struct sigevent se;126 struct itimerspec its1, its2;127 int err;128 129 /* Set up timer: */130 memset(&se, 0, sizeof(se));131 se.sigev_notify = SIGEV_SIGNAL;132 se.sigev_signo = SIGRTMAX;133 se.sigev_value.sival_int = 0;134 135 max_latency_ns = 0;136 alarmcount = 0;137 timer_fired_early = 0;138 139 err = timer_create(clock_id, &se, tm1);140 if (err) {141 if ((clock_id == CLOCK_REALTIME_ALARM) ||142 (clock_id == CLOCK_BOOTTIME_ALARM)) {143 printf("%-22s %s missing CAP_WAKE_ALARM? : [UNSUPPORTED]\n",144 clockstring(clock_id),145 flags ? "ABSTIME":"RELTIME");146 /* Indicate timer isn't set, so caller doesn't wait */147 return 1;148 }149 printf("%s - timer_create() failed\n", clockstring(clock_id));150 return -1;151 }152 153 clock_gettime(clock_id, &start_time);154 if (flags) {155 its1.it_value = start_time;156 its1.it_value.tv_sec += TIMER_SECS;157 } else {158 its1.it_value.tv_sec = TIMER_SECS;159 its1.it_value.tv_nsec = 0;160 }161 its1.it_interval.tv_sec = interval;162 its1.it_interval.tv_nsec = 0;163 164 err = timer_settime(*tm1, flags, &its1, &its2);165 if (err) {166 printf("%s - timer_settime() failed\n", clockstring(clock_id));167 return -1;168 }169 170 return 0;171}172 173int check_timer_latency(int flags, int interval)174{175 int err = 0;176 177 describe_timer(flags, interval);178 printf("timer fired early: %7d : ", timer_fired_early);179 if (!timer_fired_early) {180 printf("[OK]\n");181 } else {182 printf("[FAILED]\n");183 err = -1;184 }185 186 describe_timer(flags, interval);187 printf("max latency: %10lld ns : ", max_latency_ns);188 189 if (max_latency_ns < UNRESONABLE_LATENCY) {190 printf("[OK]\n");191 } else {192 printf("[FAILED]\n");193 err = -1;194 }195 return err;196}197 198int check_alarmcount(int flags, int interval)199{200 describe_timer(flags, interval);201 printf("count: %19d : ", alarmcount);202 if (alarmcount == 1) {203 printf("[OK]\n");204 return 0;205 }206 printf("[FAILED]\n");207 return -1;208}209 210int do_timer(int clock_id, int flags)211{212 timer_t tm1;213 const int interval = TIMER_SECS;214 int err;215 216 err = setup_timer(clock_id, flags, interval, &tm1);217 /* Unsupported case - return 0 to not fail the test */218 if (err)219 return err == 1 ? 0 : err;220 221 while (alarmcount < 5)222 sleep(1);223 224 timer_delete(tm1);225 return check_timer_latency(flags, interval);226}227 228int do_timer_oneshot(int clock_id, int flags)229{230 timer_t tm1;231 const int interval = 0;232 struct timeval timeout;233 int err;234 235 err = setup_timer(clock_id, flags, interval, &tm1);236 /* Unsupported case - return 0 to not fail the test */237 if (err)238 return err == 1 ? 0 : err;239 240 memset(&timeout, 0, sizeof(timeout));241 timeout.tv_sec = 5;242 do {243 err = select(0, NULL, NULL, NULL, &timeout);244 } while (err == -1 && errno == EINTR);245 246 timer_delete(tm1);247 err = check_timer_latency(flags, interval);248 err |= check_alarmcount(flags, interval);249 return err;250}251 252int main(void)253{254 struct sigaction act;255 int signum = SIGRTMAX;256 int ret = 0;257 258 /* Set up signal handler: */259 sigfillset(&act.sa_mask);260 act.sa_flags = 0;261 act.sa_handler = sigalarm;262 sigaction(signum, &act, NULL);263 264 printf("Setting timers for every %i seconds\n", TIMER_SECS);265 for (clock_id = 0; clock_id < NR_CLOCKIDS; clock_id++) {266 267 if ((clock_id == CLOCK_PROCESS_CPUTIME_ID) ||268 (clock_id == CLOCK_THREAD_CPUTIME_ID) ||269 (clock_id == CLOCK_MONOTONIC_RAW) ||270 (clock_id == CLOCK_REALTIME_COARSE) ||271 (clock_id == CLOCK_MONOTONIC_COARSE) ||272 (clock_id == CLOCK_HWSPECIFIC))273 continue;274 275 ret |= do_timer(clock_id, TIMER_ABSTIME);276 ret |= do_timer(clock_id, 0);277 ret |= do_timer_oneshot(clock_id, TIMER_ABSTIME);278 ret |= do_timer_oneshot(clock_id, 0);279 }280 if (ret)281 ksft_exit_fail();282 ksft_exit_pass();283}284