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4f19048f | 1 | // SPDX-License-Identifier: GPL-2.0-only |
0bc4b0cf FW |
2 | /* |
3 | * Copyright (C) 2013 Red Hat, Inc., Frederic Weisbecker <fweisbec@redhat.com> | |
4 | * | |
0bc4b0cf FW |
5 | * Selftests for a few posix timers interface. |
6 | * | |
7 | * Kernel loop code stolen from Steven Rostedt <srostedt@redhat.com> | |
8 | */ | |
9 | ||
10 | #include <sys/time.h> | |
11 | #include <stdio.h> | |
12 | #include <signal.h> | |
13 | #include <unistd.h> | |
14 | #include <time.h> | |
15 | #include <pthread.h> | |
16 | ||
88471649 SK |
17 | #include "../kselftest.h" |
18 | ||
0bc4b0cf FW |
19 | #define DELAY 2 |
20 | #define USECS_PER_SEC 1000000 | |
21 | ||
22 | static volatile int done; | |
23 | ||
24 | /* Busy loop in userspace to elapse ITIMER_VIRTUAL */ | |
25 | static void user_loop(void) | |
26 | { | |
27 | while (!done); | |
28 | } | |
29 | ||
30 | /* | |
31 | * Try to spend as much time as possible in kernelspace | |
32 | * to elapse ITIMER_PROF. | |
33 | */ | |
34 | static void kernel_loop(void) | |
35 | { | |
36 | void *addr = sbrk(0); | |
2430ec65 | 37 | int err = 0; |
0bc4b0cf | 38 | |
2430ec65 JS |
39 | while (!done && !err) { |
40 | err = brk(addr + 4096); | |
41 | err |= brk(addr); | |
0bc4b0cf FW |
42 | } |
43 | } | |
44 | ||
45 | /* | |
46 | * Sleep until ITIMER_REAL expiration. | |
47 | */ | |
48 | static void idle_loop(void) | |
49 | { | |
50 | pause(); | |
51 | } | |
52 | ||
53 | static void sig_handler(int nr) | |
54 | { | |
55 | done = 1; | |
56 | } | |
57 | ||
58 | /* | |
59 | * Check the expected timer expiration matches the GTOD elapsed delta since | |
60 | * we armed the timer. Keep a 0.5 sec error margin due to various jitter. | |
61 | */ | |
62 | static int check_diff(struct timeval start, struct timeval end) | |
63 | { | |
64 | long long diff; | |
65 | ||
66 | diff = end.tv_usec - start.tv_usec; | |
67 | diff += (end.tv_sec - start.tv_sec) * USECS_PER_SEC; | |
68 | ||
ed366de8 | 69 | if (llabs(diff - DELAY * USECS_PER_SEC) > USECS_PER_SEC / 2) { |
0bc4b0cf FW |
70 | printf("Diff too high: %lld..", diff); |
71 | return -1; | |
72 | } | |
73 | ||
74 | return 0; | |
75 | } | |
76 | ||
77 | static int check_itimer(int which) | |
78 | { | |
071af0c9 | 79 | const char *name; |
0bc4b0cf FW |
80 | int err; |
81 | struct timeval start, end; | |
82 | struct itimerval val = { | |
83 | .it_value.tv_sec = DELAY, | |
84 | }; | |
85 | ||
0bc4b0cf | 86 | if (which == ITIMER_VIRTUAL) |
071af0c9 | 87 | name = "ITIMER_VIRTUAL"; |
0bc4b0cf | 88 | else if (which == ITIMER_PROF) |
071af0c9 | 89 | name = "ITIMER_PROF"; |
0bc4b0cf | 90 | else if (which == ITIMER_REAL) |
071af0c9 MB |
91 | name = "ITIMER_REAL"; |
92 | else | |
93 | return -1; | |
0bc4b0cf FW |
94 | |
95 | done = 0; | |
96 | ||
97 | if (which == ITIMER_VIRTUAL) | |
98 | signal(SIGVTALRM, sig_handler); | |
99 | else if (which == ITIMER_PROF) | |
100 | signal(SIGPROF, sig_handler); | |
101 | else if (which == ITIMER_REAL) | |
102 | signal(SIGALRM, sig_handler); | |
103 | ||
104 | err = gettimeofday(&start, NULL); | |
105 | if (err < 0) { | |
071af0c9 | 106 | ksft_perror("Can't call gettimeofday()"); |
0bc4b0cf FW |
107 | return -1; |
108 | } | |
109 | ||
110 | err = setitimer(which, &val, NULL); | |
111 | if (err < 0) { | |
071af0c9 | 112 | ksft_perror("Can't set timer"); |
0bc4b0cf FW |
113 | return -1; |
114 | } | |
115 | ||
116 | if (which == ITIMER_VIRTUAL) | |
117 | user_loop(); | |
118 | else if (which == ITIMER_PROF) | |
119 | kernel_loop(); | |
120 | else if (which == ITIMER_REAL) | |
121 | idle_loop(); | |
122 | ||
c3cb8356 | 123 | err = gettimeofday(&end, NULL); |
0bc4b0cf | 124 | if (err < 0) { |
071af0c9 | 125 | ksft_perror("Can't call gettimeofday()"); |
0bc4b0cf FW |
126 | return -1; |
127 | } | |
128 | ||
071af0c9 | 129 | ksft_test_result(check_diff(start, end) == 0, "%s\n", name); |
0bc4b0cf FW |
130 | |
131 | return 0; | |
132 | } | |
133 | ||
134 | static int check_timer_create(int which) | |
135 | { | |
071af0c9 | 136 | const char *type; |
0bc4b0cf FW |
137 | int err; |
138 | timer_t id; | |
139 | struct timeval start, end; | |
140 | struct itimerspec val = { | |
141 | .it_value.tv_sec = DELAY, | |
142 | }; | |
143 | ||
0bc4b0cf | 144 | if (which == CLOCK_THREAD_CPUTIME_ID) { |
071af0c9 | 145 | type = "thread"; |
0bc4b0cf | 146 | } else if (which == CLOCK_PROCESS_CPUTIME_ID) { |
071af0c9 MB |
147 | type = "process"; |
148 | } else { | |
149 | ksft_print_msg("Unknown timer_create() type %d\n", which); | |
150 | return -1; | |
0bc4b0cf | 151 | } |
0bc4b0cf FW |
152 | |
153 | done = 0; | |
c88b05b2 | 154 | err = timer_create(which, NULL, &id); |
0bc4b0cf | 155 | if (err < 0) { |
071af0c9 | 156 | ksft_perror("Can't create timer"); |
0bc4b0cf FW |
157 | return -1; |
158 | } | |
159 | signal(SIGALRM, sig_handler); | |
160 | ||
161 | err = gettimeofday(&start, NULL); | |
162 | if (err < 0) { | |
071af0c9 | 163 | ksft_perror("Can't call gettimeofday()"); |
0bc4b0cf FW |
164 | return -1; |
165 | } | |
166 | ||
167 | err = timer_settime(id, 0, &val, NULL); | |
168 | if (err < 0) { | |
071af0c9 | 169 | ksft_perror("Can't set timer"); |
0bc4b0cf FW |
170 | return -1; |
171 | } | |
172 | ||
173 | user_loop(); | |
174 | ||
c3cb8356 | 175 | err = gettimeofday(&end, NULL); |
0bc4b0cf | 176 | if (err < 0) { |
071af0c9 | 177 | ksft_perror("Can't call gettimeofday()"); |
0bc4b0cf FW |
178 | return -1; |
179 | } | |
180 | ||
071af0c9 MB |
181 | ksft_test_result(check_diff(start, end) == 0, |
182 | "timer_create() per %s\n", type); | |
0bc4b0cf FW |
183 | |
184 | return 0; | |
185 | } | |
186 | ||
6d029c25 ON |
187 | static pthread_t ctd_thread; |
188 | static volatile int ctd_count, ctd_failed; | |
e797203f | 189 | |
6d029c25 | 190 | static void ctd_sighandler(int sig) |
e797203f | 191 | { |
6d029c25 ON |
192 | if (pthread_self() != ctd_thread) |
193 | ctd_failed = 1; | |
194 | ctd_count--; | |
e797203f DV |
195 | } |
196 | ||
6d029c25 | 197 | static void *ctd_thread_func(void *arg) |
e797203f | 198 | { |
e797203f DV |
199 | struct itimerspec val = { |
200 | .it_value.tv_sec = 0, | |
201 | .it_value.tv_nsec = 1000 * 1000, | |
202 | .it_interval.tv_sec = 0, | |
203 | .it_interval.tv_nsec = 1000 * 1000, | |
204 | }; | |
6d029c25 | 205 | timer_t id; |
e797203f | 206 | |
6d029c25 ON |
207 | /* 1/10 seconds to ensure the leader sleeps */ |
208 | usleep(10000); | |
e797203f | 209 | |
6d029c25 ON |
210 | ctd_count = 100; |
211 | if (timer_create(CLOCK_PROCESS_CPUTIME_ID, NULL, &id)) | |
212 | return "Can't create timer\n"; | |
213 | if (timer_settime(id, 0, &val, NULL)) | |
214 | return "Can't set timer\n"; | |
e797203f | 215 | |
6d029c25 ON |
216 | while (ctd_count > 0 && !ctd_failed) |
217 | ; | |
e797203f | 218 | |
6d029c25 ON |
219 | if (timer_delete(id)) |
220 | return "Can't delete timer\n"; | |
e797203f | 221 | |
6d029c25 ON |
222 | return NULL; |
223 | } | |
224 | ||
225 | /* | |
226 | * Test that only the running thread receives the timer signal. | |
227 | */ | |
228 | static int check_timer_distribution(void) | |
229 | { | |
230 | const char *errmsg; | |
e797203f | 231 | |
6d029c25 ON |
232 | signal(SIGALRM, ctd_sighandler); |
233 | ||
234 | errmsg = "Can't create thread\n"; | |
235 | if (pthread_create(&ctd_thread, NULL, ctd_thread_func, NULL)) | |
236 | goto err; | |
237 | ||
238 | errmsg = "Can't join thread\n"; | |
239 | if (pthread_join(ctd_thread, (void **)&errmsg) || errmsg) | |
240 | goto err; | |
241 | ||
242 | if (!ctd_failed) | |
243 | ksft_test_result_pass("check signal distribution\n"); | |
244 | else if (ksft_min_kernel_version(6, 3)) | |
245 | ksft_test_result_fail("check signal distribution\n"); | |
246 | else | |
247 | ksft_test_result_skip("check signal distribution (old kernel)\n"); | |
e797203f | 248 | return 0; |
6d029c25 | 249 | err: |
e4a6bcea | 250 | ksft_print_msg("%s", errmsg); |
6d029c25 | 251 | return -1; |
e797203f DV |
252 | } |
253 | ||
0bc4b0cf FW |
254 | int main(int argc, char **argv) |
255 | { | |
071af0c9 MB |
256 | ksft_print_header(); |
257 | ksft_set_plan(6); | |
258 | ||
259 | ksft_print_msg("Testing posix timers. False negative may happen on CPU execution \n"); | |
260 | ksft_print_msg("based timers if other threads run on the CPU...\n"); | |
0bc4b0cf FW |
261 | |
262 | if (check_itimer(ITIMER_VIRTUAL) < 0) | |
88471649 | 263 | return ksft_exit_fail(); |
0bc4b0cf FW |
264 | |
265 | if (check_itimer(ITIMER_PROF) < 0) | |
88471649 | 266 | return ksft_exit_fail(); |
0bc4b0cf FW |
267 | |
268 | if (check_itimer(ITIMER_REAL) < 0) | |
88471649 | 269 | return ksft_exit_fail(); |
0bc4b0cf FW |
270 | |
271 | if (check_timer_create(CLOCK_THREAD_CPUTIME_ID) < 0) | |
88471649 | 272 | return ksft_exit_fail(); |
0bc4b0cf FW |
273 | |
274 | /* | |
275 | * It's unfortunately hard to reliably test a timer expiration | |
276 | * on parallel multithread cputime. We could arm it to expire | |
277 | * on DELAY * nr_threads, with nr_threads busy looping, then wait | |
278 | * the normal DELAY since the time is elapsing nr_threads faster. | |
279 | * But for that we need to ensure we have real physical free CPUs | |
280 | * to ensure true parallelism. So test only one thread until we | |
281 | * find a better solution. | |
282 | */ | |
283 | if (check_timer_create(CLOCK_PROCESS_CPUTIME_ID) < 0) | |
88471649 | 284 | return ksft_exit_fail(); |
0bc4b0cf | 285 | |
e797203f DV |
286 | if (check_timer_distribution() < 0) |
287 | return ksft_exit_fail(); | |
288 | ||
071af0c9 | 289 | ksft_finished(); |
0bc4b0cf | 290 | } |