Frederic Weisbecker | 0bc4b0c | 2013-06-28 00:06:43 +0000 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2013 Red Hat, Inc., Frederic Weisbecker <fweisbec@redhat.com> |
| 3 | * |
| 4 | * Licensed under the terms of the GNU GPL License version 2 |
| 5 | * |
| 6 | * Selftests for a few posix timers interface. |
| 7 | * |
| 8 | * Kernel loop code stolen from Steven Rostedt <srostedt@redhat.com> |
| 9 | */ |
| 10 | |
| 11 | #include <sys/time.h> |
| 12 | #include <stdio.h> |
| 13 | #include <signal.h> |
| 14 | #include <unistd.h> |
| 15 | #include <time.h> |
| 16 | #include <pthread.h> |
| 17 | |
Shuah Khan | 8847164 | 2014-10-03 09:08:56 -0600 | [diff] [blame] | 18 | #include "../kselftest.h" |
| 19 | |
Frederic Weisbecker | 0bc4b0c | 2013-06-28 00:06:43 +0000 | [diff] [blame] | 20 | #define DELAY 2 |
| 21 | #define USECS_PER_SEC 1000000 |
| 22 | |
| 23 | static volatile int done; |
| 24 | |
| 25 | /* Busy loop in userspace to elapse ITIMER_VIRTUAL */ |
| 26 | static void user_loop(void) |
| 27 | { |
| 28 | while (!done); |
| 29 | } |
| 30 | |
| 31 | /* |
| 32 | * Try to spend as much time as possible in kernelspace |
| 33 | * to elapse ITIMER_PROF. |
| 34 | */ |
| 35 | static void kernel_loop(void) |
| 36 | { |
| 37 | void *addr = sbrk(0); |
John Stultz | 2430ec6 | 2015-03-11 17:39:58 -0700 | [diff] [blame] | 38 | int err = 0; |
Frederic Weisbecker | 0bc4b0c | 2013-06-28 00:06:43 +0000 | [diff] [blame] | 39 | |
John Stultz | 2430ec6 | 2015-03-11 17:39:58 -0700 | [diff] [blame] | 40 | while (!done && !err) { |
| 41 | err = brk(addr + 4096); |
| 42 | err |= brk(addr); |
Frederic Weisbecker | 0bc4b0c | 2013-06-28 00:06:43 +0000 | [diff] [blame] | 43 | } |
| 44 | } |
| 45 | |
| 46 | /* |
| 47 | * Sleep until ITIMER_REAL expiration. |
| 48 | */ |
| 49 | static void idle_loop(void) |
| 50 | { |
| 51 | pause(); |
| 52 | } |
| 53 | |
| 54 | static void sig_handler(int nr) |
| 55 | { |
| 56 | done = 1; |
| 57 | } |
| 58 | |
| 59 | /* |
| 60 | * Check the expected timer expiration matches the GTOD elapsed delta since |
| 61 | * we armed the timer. Keep a 0.5 sec error margin due to various jitter. |
| 62 | */ |
| 63 | static int check_diff(struct timeval start, struct timeval end) |
| 64 | { |
| 65 | long long diff; |
| 66 | |
| 67 | diff = end.tv_usec - start.tv_usec; |
| 68 | diff += (end.tv_sec - start.tv_sec) * USECS_PER_SEC; |
| 69 | |
| 70 | if (abs(diff - DELAY * USECS_PER_SEC) > USECS_PER_SEC / 2) { |
| 71 | printf("Diff too high: %lld..", diff); |
| 72 | return -1; |
| 73 | } |
| 74 | |
| 75 | return 0; |
| 76 | } |
| 77 | |
| 78 | static int check_itimer(int which) |
| 79 | { |
| 80 | int err; |
| 81 | struct timeval start, end; |
| 82 | struct itimerval val = { |
| 83 | .it_value.tv_sec = DELAY, |
| 84 | }; |
| 85 | |
| 86 | printf("Check itimer "); |
| 87 | |
| 88 | if (which == ITIMER_VIRTUAL) |
| 89 | printf("virtual... "); |
| 90 | else if (which == ITIMER_PROF) |
| 91 | printf("prof... "); |
| 92 | else if (which == ITIMER_REAL) |
| 93 | printf("real... "); |
| 94 | |
| 95 | fflush(stdout); |
| 96 | |
| 97 | done = 0; |
| 98 | |
| 99 | if (which == ITIMER_VIRTUAL) |
| 100 | signal(SIGVTALRM, sig_handler); |
| 101 | else if (which == ITIMER_PROF) |
| 102 | signal(SIGPROF, sig_handler); |
| 103 | else if (which == ITIMER_REAL) |
| 104 | signal(SIGALRM, sig_handler); |
| 105 | |
| 106 | err = gettimeofday(&start, NULL); |
| 107 | if (err < 0) { |
| 108 | perror("Can't call gettimeofday()\n"); |
| 109 | return -1; |
| 110 | } |
| 111 | |
| 112 | err = setitimer(which, &val, NULL); |
| 113 | if (err < 0) { |
| 114 | perror("Can't set timer\n"); |
| 115 | return -1; |
| 116 | } |
| 117 | |
| 118 | if (which == ITIMER_VIRTUAL) |
| 119 | user_loop(); |
| 120 | else if (which == ITIMER_PROF) |
| 121 | kernel_loop(); |
| 122 | else if (which == ITIMER_REAL) |
| 123 | idle_loop(); |
| 124 | |
| 125 | gettimeofday(&end, NULL); |
| 126 | if (err < 0) { |
| 127 | perror("Can't call gettimeofday()\n"); |
| 128 | return -1; |
| 129 | } |
| 130 | |
| 131 | if (!check_diff(start, end)) |
| 132 | printf("[OK]\n"); |
| 133 | else |
| 134 | printf("[FAIL]\n"); |
| 135 | |
| 136 | return 0; |
| 137 | } |
| 138 | |
| 139 | static int check_timer_create(int which) |
| 140 | { |
| 141 | int err; |
| 142 | timer_t id; |
| 143 | struct timeval start, end; |
| 144 | struct itimerspec val = { |
| 145 | .it_value.tv_sec = DELAY, |
| 146 | }; |
| 147 | |
| 148 | printf("Check timer_create() "); |
| 149 | if (which == CLOCK_THREAD_CPUTIME_ID) { |
| 150 | printf("per thread... "); |
| 151 | } else if (which == CLOCK_PROCESS_CPUTIME_ID) { |
| 152 | printf("per process... "); |
| 153 | } |
| 154 | fflush(stdout); |
| 155 | |
| 156 | done = 0; |
Felipe Pena | c88b05b | 2013-10-16 13:46:58 -0700 | [diff] [blame] | 157 | err = timer_create(which, NULL, &id); |
Frederic Weisbecker | 0bc4b0c | 2013-06-28 00:06:43 +0000 | [diff] [blame] | 158 | if (err < 0) { |
| 159 | perror("Can't create timer\n"); |
| 160 | return -1; |
| 161 | } |
| 162 | signal(SIGALRM, sig_handler); |
| 163 | |
| 164 | err = gettimeofday(&start, NULL); |
| 165 | if (err < 0) { |
| 166 | perror("Can't call gettimeofday()\n"); |
| 167 | return -1; |
| 168 | } |
| 169 | |
| 170 | err = timer_settime(id, 0, &val, NULL); |
| 171 | if (err < 0) { |
| 172 | perror("Can't set timer\n"); |
| 173 | return -1; |
| 174 | } |
| 175 | |
| 176 | user_loop(); |
| 177 | |
| 178 | gettimeofday(&end, NULL); |
| 179 | if (err < 0) { |
| 180 | perror("Can't call gettimeofday()\n"); |
| 181 | return -1; |
| 182 | } |
| 183 | |
| 184 | if (!check_diff(start, end)) |
| 185 | printf("[OK]\n"); |
| 186 | else |
| 187 | printf("[FAIL]\n"); |
| 188 | |
| 189 | return 0; |
| 190 | } |
| 191 | |
| 192 | int main(int argc, char **argv) |
| 193 | { |
Frederic Weisbecker | 0bc4b0c | 2013-06-28 00:06:43 +0000 | [diff] [blame] | 194 | printf("Testing posix timers. False negative may happen on CPU execution \n"); |
| 195 | printf("based timers if other threads run on the CPU...\n"); |
| 196 | |
| 197 | if (check_itimer(ITIMER_VIRTUAL) < 0) |
Shuah Khan | 8847164 | 2014-10-03 09:08:56 -0600 | [diff] [blame] | 198 | return ksft_exit_fail(); |
Frederic Weisbecker | 0bc4b0c | 2013-06-28 00:06:43 +0000 | [diff] [blame] | 199 | |
| 200 | if (check_itimer(ITIMER_PROF) < 0) |
Shuah Khan | 8847164 | 2014-10-03 09:08:56 -0600 | [diff] [blame] | 201 | return ksft_exit_fail(); |
Frederic Weisbecker | 0bc4b0c | 2013-06-28 00:06:43 +0000 | [diff] [blame] | 202 | |
| 203 | if (check_itimer(ITIMER_REAL) < 0) |
Shuah Khan | 8847164 | 2014-10-03 09:08:56 -0600 | [diff] [blame] | 204 | return ksft_exit_fail(); |
Frederic Weisbecker | 0bc4b0c | 2013-06-28 00:06:43 +0000 | [diff] [blame] | 205 | |
| 206 | if (check_timer_create(CLOCK_THREAD_CPUTIME_ID) < 0) |
Shuah Khan | 8847164 | 2014-10-03 09:08:56 -0600 | [diff] [blame] | 207 | return ksft_exit_fail(); |
Frederic Weisbecker | 0bc4b0c | 2013-06-28 00:06:43 +0000 | [diff] [blame] | 208 | |
| 209 | /* |
| 210 | * It's unfortunately hard to reliably test a timer expiration |
| 211 | * on parallel multithread cputime. We could arm it to expire |
| 212 | * on DELAY * nr_threads, with nr_threads busy looping, then wait |
| 213 | * the normal DELAY since the time is elapsing nr_threads faster. |
| 214 | * But for that we need to ensure we have real physical free CPUs |
| 215 | * to ensure true parallelism. So test only one thread until we |
| 216 | * find a better solution. |
| 217 | */ |
| 218 | if (check_timer_create(CLOCK_PROCESS_CPUTIME_ID) < 0) |
Shuah Khan | 8847164 | 2014-10-03 09:08:56 -0600 | [diff] [blame] | 219 | return ksft_exit_fail(); |
Frederic Weisbecker | 0bc4b0c | 2013-06-28 00:06:43 +0000 | [diff] [blame] | 220 | |
Shuah Khan | 8847164 | 2014-10-03 09:08:56 -0600 | [diff] [blame] | 221 | return ksft_exit_pass(); |
Frederic Weisbecker | 0bc4b0c | 2013-06-28 00:06:43 +0000 | [diff] [blame] | 222 | } |