1 | /* set_timer latency test |
2 | * John Stultz (john.stultz@linaro.org) |
3 | * (C) Copyright Linaro 2014 |
4 | * Licensed under the GPLv2 |
5 | * |
6 | * This test makes sure the set_timer api is correct |
7 | * |
8 | * To build: |
9 | * $ gcc set-timer-lat.c -o set-timer-lat -lrt |
10 | * |
11 | * This program is free software: you can redistribute it and/or modify |
12 | * it under the terms of the GNU General Public License as published by |
13 | * the Free Software Foundation, either version 2 of the License, or |
14 | * (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 of |
18 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
19 | * 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 0 |
34 | #define CLOCK_MONOTONIC 1 |
35 | #define CLOCK_PROCESS_CPUTIME_ID 2 |
36 | #define CLOCK_THREAD_CPUTIME_ID 3 |
37 | #define CLOCK_MONOTONIC_RAW 4 |
38 | #define CLOCK_REALTIME_COARSE 5 |
39 | #define CLOCK_MONOTONIC_COARSE 6 |
40 | #define CLOCK_BOOTTIME 7 |
41 | #define CLOCK_REALTIME_ALARM 8 |
42 | #define CLOCK_BOOTTIME_ALARM 9 |
43 | #define CLOCK_HWSPECIFIC 10 |
44 | #define CLOCK_TAI 11 |
45 | #define NR_CLOCKIDS 12 |
46 | |
47 | |
48 | #define NSEC_PER_SEC 1000000000ULL |
49 | #define UNRESONABLE_LATENCY 40000000 /* 40ms in nanosecs */ |
50 | |
51 | #define TIMER_SECS 1 |
52 | int alarmcount; |
53 | int clock_id; |
54 | struct timespec start_time; |
55 | long long max_latency_ns; |
56 | int timer_fired_early; |
57 | |
58 | char *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 | |
88 | long 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 | |
97 | void 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(a: start_time, b: 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 | |
115 | void describe_timer(int flags, int interval) |
116 | { |
117 | printf("%-22s %s %s " , |
118 | clockstring(clockid: clock_id), |
119 | flags ? "ABSTIME" :"RELTIME" , |
120 | interval ? "PERIODIC" :"ONE-SHOT" ); |
121 | } |
122 | |
123 | int 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(clockid: 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(clockid: 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(clockid: clock_id)); |
167 | return -1; |
168 | } |
169 | |
170 | return 0; |
171 | } |
172 | |
173 | int 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 | |
198 | int 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 | |
210 | int 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 | |
228 | int 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 | |
252 | int 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, flags: TIMER_ABSTIME); |
276 | ret |= do_timer(clock_id, flags: 0); |
277 | ret |= do_timer_oneshot(clock_id, flags: TIMER_ABSTIME); |
278 | ret |= do_timer_oneshot(clock_id, flags: 0); |
279 | } |
280 | if (ret) |
281 | return ksft_exit_fail(); |
282 | return ksft_exit_pass(); |
283 | } |
284 | |