xref: /dpdk/app/test/test_timer.c (revision daa02b5cddbb8e11b31d41e2bf7bb1ae64dcae2f)
1 /* SPDX-License-Identifier: BSD-3-Clause
2  * Copyright(c) 2010-2014 Intel Corporation
3  */
4 
5 #include "test.h"
6 
7 /*
8  * Timer
9  * =====
10  *
11  * #. Stress test 1.
12  *
13  *    The objective of the timer stress tests is to check that there are no
14  *    race conditions in list and status management. This test launches,
15  *    resets and stops the timer very often on many cores at the same
16  *    time.
17  *
18  *    - Only one timer is used for this test.
19  *    - On each core, the rte_timer_manage() function is called from the main
20  *      loop every 3 microseconds.
21  *    - In the main loop, the timer may be reset (randomly, with a
22  *      probability of 0.5 %) 100 microseconds later on a random core, or
23  *      stopped (with a probability of 0.5 % also).
24  *    - In callback, the timer is can be reset (randomly, with a
25  *      probability of 0.5 %) 100 microseconds later on the same core or
26  *      on another core (same probability), or stopped (same
27  *      probability).
28  *
29  * # Stress test 2.
30  *
31  *    The objective of this test is similar to the first in that it attempts
32  *    to find if there are any race conditions in the timer library. However,
33  *    it is less complex in terms of operations performed and duration, as it
34  *    is designed to have a predictable outcome that can be tested.
35  *
36  *    - A set of timers is initialized for use by the test
37  *    - All cores then simultaneously are set to schedule all the timers at
38  *      the same time, so conflicts should occur.
39  *    - Then there is a delay while we wait for the timers to expire
40  *    - Then the main lcore calls timer_manage() and we check that all
41  *      timers have had their callbacks called exactly once - no more no less.
42  *    - Then we repeat the process, except after setting up the timers, we have
43  *      all cores randomly reschedule them.
44  *    - Again we check that the expected number of callbacks has occurred when
45  *      we call timer-manage.
46  *
47  * #. Basic test.
48  *
49  *    This test performs basic functional checks of the timers. The test
50  *    uses four different timers that are loaded and stopped under
51  *    specific conditions in specific contexts.
52  *
53  *    - Four timers are used for this test.
54  *    - On each core, the rte_timer_manage() function is called from main loop
55  *      every 3 microseconds.
56  *
57  *    The autotest python script checks that the behavior is correct:
58  *
59  *    - timer0
60  *
61  *      - At initialization, timer0 is loaded by the main core, on main core
62  *        in "single" mode (time = 1 second).
63  *      - In the first 19 callbacks, timer0 is reloaded on the same core,
64  *        then, it is explicitly stopped at the 20th call.
65  *      - At t=25s, timer0 is reloaded once by timer2.
66  *
67  *    - timer1
68  *
69  *      - At initialization, timer1 is loaded by the main core, on the
70  *        main core in "single" mode (time = 2 seconds).
71  *      - In the first 9 callbacks, timer1 is reloaded on another
72  *        core. After the 10th callback, timer1 is not reloaded anymore.
73  *
74  *    - timer2
75  *
76  *      - At initialization, timer2 is loaded by the main core, on the
77  *        main core in "periodical" mode (time = 1 second).
78  *      - In the callback, when t=25s, it stops timer3 and reloads timer0
79  *        on the current core.
80  *
81  *    - timer3
82  *
83  *      - At initialization, timer3 is loaded by the main core, on
84  *        another core in "periodical" mode (time = 1 second).
85  *      - It is stopped at t=25s by timer2.
86  */
87 
88 #include <stdio.h>
89 #include <stdarg.h>
90 #include <string.h>
91 #include <stdlib.h>
92 #include <stdint.h>
93 #include <inttypes.h>
94 #include <sys/queue.h>
95 #include <math.h>
96 
97 #include <rte_common.h>
98 #include <rte_log.h>
99 #include <rte_memory.h>
100 #include <rte_launch.h>
101 #include <rte_cycles.h>
102 #include <rte_eal.h>
103 #include <rte_per_lcore.h>
104 #include <rte_lcore.h>
105 #include <rte_atomic.h>
106 #include <rte_timer.h>
107 #include <rte_random.h>
108 #include <rte_malloc.h>
109 #include <rte_pause.h>
110 
111 #define TEST_DURATION_S 1 /* in seconds */
112 #define NB_TIMER 4
113 
114 #define RTE_LOGTYPE_TESTTIMER RTE_LOGTYPE_USER3
115 
116 static volatile uint64_t end_time;
117 static volatile int test_failed;
118 
119 struct mytimerinfo {
120 	struct rte_timer tim;
121 	unsigned id;
122 	unsigned count;
123 };
124 
125 static struct mytimerinfo mytiminfo[NB_TIMER];
126 
127 static void timer_basic_cb(struct rte_timer *tim, void *arg);
128 
129 static void
130 mytimer_reset(struct mytimerinfo *timinfo, uint64_t ticks,
131 	      enum rte_timer_type type, unsigned tim_lcore,
132 	      rte_timer_cb_t fct)
133 {
134 	rte_timer_reset_sync(&timinfo->tim, ticks, type, tim_lcore,
135 			     fct, timinfo);
136 }
137 
138 /* timer callback for stress tests */
139 static void
140 timer_stress_cb(__rte_unused struct rte_timer *tim,
141 		__rte_unused void *arg)
142 {
143 	long r;
144 	unsigned lcore_id = rte_lcore_id();
145 	uint64_t hz = rte_get_timer_hz();
146 
147 	if (rte_timer_pending(tim))
148 		return;
149 
150 	r = rte_rand();
151 	if ((r & 0xff) == 0) {
152 		mytimer_reset(&mytiminfo[0], hz, SINGLE, lcore_id,
153 			      timer_stress_cb);
154 	}
155 	else if ((r & 0xff) == 1) {
156 		mytimer_reset(&mytiminfo[0], hz, SINGLE,
157 			      rte_get_next_lcore(lcore_id, 0, 1),
158 			      timer_stress_cb);
159 	}
160 	else if ((r & 0xff) == 2) {
161 		rte_timer_stop(&mytiminfo[0].tim);
162 	}
163 }
164 
165 static int
166 timer_stress_main_loop(__rte_unused void *arg)
167 {
168 	uint64_t hz = rte_get_timer_hz();
169 	unsigned lcore_id = rte_lcore_id();
170 	uint64_t cur_time;
171 	int64_t diff = 0;
172 	long r;
173 
174 	while (diff >= 0) {
175 
176 		/* call the timer handler on each core */
177 		rte_timer_manage();
178 
179 		/* simulate the processing of a packet
180 		 * (1 us = 2000 cycles at 2 Ghz) */
181 		rte_delay_us(1);
182 
183 		/* randomly stop or reset timer */
184 		r = rte_rand();
185 		lcore_id = rte_get_next_lcore(lcore_id, 0, 1);
186 		if ((r & 0xff) == 0) {
187 			/* 100 us */
188 			mytimer_reset(&mytiminfo[0], hz/10000, SINGLE, lcore_id,
189 				      timer_stress_cb);
190 		}
191 		else if ((r & 0xff) == 1) {
192 			rte_timer_stop_sync(&mytiminfo[0].tim);
193 		}
194 		cur_time = rte_get_timer_cycles();
195 		diff = end_time - cur_time;
196 	}
197 
198 	lcore_id = rte_lcore_id();
199 	RTE_LOG(INFO, TESTTIMER, "core %u finished\n", lcore_id);
200 
201 	return 0;
202 }
203 
204 /* Need to synchronize worker lcores through multiple steps. */
205 enum { WORKER_WAITING = 1, WORKER_RUN_SIGNAL, WORKER_RUNNING, WORKER_FINISHED };
206 static rte_atomic16_t lcore_state[RTE_MAX_LCORE];
207 
208 static void
209 main_init_workers(void)
210 {
211 	unsigned i;
212 
213 	RTE_LCORE_FOREACH_WORKER(i) {
214 		rte_atomic16_set(&lcore_state[i], WORKER_WAITING);
215 	}
216 }
217 
218 static void
219 main_start_workers(void)
220 {
221 	unsigned i;
222 
223 	RTE_LCORE_FOREACH_WORKER(i) {
224 		rte_atomic16_set(&lcore_state[i], WORKER_RUN_SIGNAL);
225 	}
226 	RTE_LCORE_FOREACH_WORKER(i) {
227 		while (rte_atomic16_read(&lcore_state[i]) != WORKER_RUNNING)
228 			rte_pause();
229 	}
230 }
231 
232 static void
233 main_wait_for_workers(void)
234 {
235 	unsigned i;
236 
237 	RTE_LCORE_FOREACH_WORKER(i) {
238 		while (rte_atomic16_read(&lcore_state[i]) != WORKER_FINISHED)
239 			rte_pause();
240 	}
241 }
242 
243 static void
244 worker_wait_to_start(void)
245 {
246 	unsigned lcore_id = rte_lcore_id();
247 
248 	while (rte_atomic16_read(&lcore_state[lcore_id]) != WORKER_RUN_SIGNAL)
249 		rte_pause();
250 	rte_atomic16_set(&lcore_state[lcore_id], WORKER_RUNNING);
251 }
252 
253 static void
254 worker_finish(void)
255 {
256 	unsigned lcore_id = rte_lcore_id();
257 
258 	rte_atomic16_set(&lcore_state[lcore_id], WORKER_FINISHED);
259 }
260 
261 
262 static volatile int cb_count = 0;
263 
264 /* callback for second stress test. will only be called
265  * on main lcore
266  */
267 static void
268 timer_stress2_cb(struct rte_timer *tim __rte_unused, void *arg __rte_unused)
269 {
270 	cb_count++;
271 }
272 
273 #define NB_STRESS2_TIMERS 8192
274 
275 static int
276 timer_stress2_main_loop(__rte_unused void *arg)
277 {
278 	static struct rte_timer *timers;
279 	int i, ret;
280 	uint64_t delay = rte_get_timer_hz() / 20;
281 	unsigned int lcore_id = rte_lcore_id();
282 	unsigned int main_lcore = rte_get_main_lcore();
283 	int32_t my_collisions = 0;
284 	static rte_atomic32_t collisions;
285 
286 	if (lcore_id == main_lcore) {
287 		cb_count = 0;
288 		test_failed = 0;
289 		rte_atomic32_set(&collisions, 0);
290 		main_init_workers();
291 		timers = rte_malloc(NULL, sizeof(*timers) * NB_STRESS2_TIMERS, 0);
292 		if (timers == NULL) {
293 			printf("Test Failed\n");
294 			printf("- Cannot allocate memory for timers\n" );
295 			test_failed = 1;
296 			main_start_workers();
297 			goto cleanup;
298 		}
299 		for (i = 0; i < NB_STRESS2_TIMERS; i++)
300 			rte_timer_init(&timers[i]);
301 		main_start_workers();
302 	} else {
303 		worker_wait_to_start();
304 		if (test_failed)
305 			goto cleanup;
306 	}
307 
308 	/* have all cores schedule all timers on main lcore */
309 	for (i = 0; i < NB_STRESS2_TIMERS; i++) {
310 		ret = rte_timer_reset(&timers[i], delay, SINGLE, main_lcore,
311 				timer_stress2_cb, NULL);
312 		/* there will be collisions when multiple cores simultaneously
313 		 * configure the same timers */
314 		if (ret != 0)
315 			my_collisions++;
316 	}
317 	if (my_collisions != 0)
318 		rte_atomic32_add(&collisions, my_collisions);
319 
320 	/* wait long enough for timers to expire */
321 	rte_delay_ms(100);
322 
323 	/* all cores rendezvous */
324 	if (lcore_id == main_lcore) {
325 		main_wait_for_workers();
326 	} else {
327 		worker_finish();
328 	}
329 
330 	/* now check that we get the right number of callbacks */
331 	if (lcore_id == main_lcore) {
332 		my_collisions = rte_atomic32_read(&collisions);
333 		if (my_collisions != 0)
334 			printf("- %d timer reset collisions (OK)\n", my_collisions);
335 		rte_timer_manage();
336 		if (cb_count != NB_STRESS2_TIMERS) {
337 			printf("Test Failed\n");
338 			printf("- Stress test 2, part 1 failed\n");
339 			printf("- Expected %d callbacks, got %d\n", NB_STRESS2_TIMERS,
340 					cb_count);
341 			test_failed = 1;
342 			main_start_workers();
343 			goto cleanup;
344 		}
345 		cb_count = 0;
346 
347 		/* proceed */
348 		main_start_workers();
349 	} else {
350 		/* proceed */
351 		worker_wait_to_start();
352 		if (test_failed)
353 			goto cleanup;
354 	}
355 
356 	/* now test again, just stop and restart timers at random after init*/
357 	for (i = 0; i < NB_STRESS2_TIMERS; i++)
358 		rte_timer_reset(&timers[i], delay, SINGLE, main_lcore,
359 				timer_stress2_cb, NULL);
360 
361 	/* pick random timer to reset, stopping them first half the time */
362 	for (i = 0; i < 100000; i++) {
363 		int r = rand() % NB_STRESS2_TIMERS;
364 		if (i % 2)
365 			rte_timer_stop(&timers[r]);
366 		rte_timer_reset(&timers[r], delay, SINGLE, main_lcore,
367 				timer_stress2_cb, NULL);
368 	}
369 
370 	/* wait long enough for timers to expire */
371 	rte_delay_ms(100);
372 
373 	/* now check that we get the right number of callbacks */
374 	if (lcore_id == main_lcore) {
375 		main_wait_for_workers();
376 
377 		rte_timer_manage();
378 		if (cb_count != NB_STRESS2_TIMERS) {
379 			printf("Test Failed\n");
380 			printf("- Stress test 2, part 2 failed\n");
381 			printf("- Expected %d callbacks, got %d\n", NB_STRESS2_TIMERS,
382 					cb_count);
383 			test_failed = 1;
384 		} else {
385 			printf("Test OK\n");
386 		}
387 	}
388 
389 cleanup:
390 	if (lcore_id == main_lcore) {
391 		main_wait_for_workers();
392 		if (timers != NULL) {
393 			rte_free(timers);
394 			timers = NULL;
395 		}
396 	} else {
397 		worker_finish();
398 	}
399 
400 	return 0;
401 }
402 
403 /* timer callback for basic tests */
404 static void
405 timer_basic_cb(struct rte_timer *tim, void *arg)
406 {
407 	struct mytimerinfo *timinfo = arg;
408 	uint64_t hz = rte_get_timer_hz();
409 	unsigned lcore_id = rte_lcore_id();
410 	uint64_t cur_time = rte_get_timer_cycles();
411 
412 	if (rte_timer_pending(tim))
413 		return;
414 
415 	timinfo->count ++;
416 
417 	RTE_LOG(INFO, TESTTIMER,
418 		"%"PRIu64": callback id=%u count=%u on core %u\n",
419 		cur_time, timinfo->id, timinfo->count, lcore_id);
420 
421 	/* reload timer 0 on same core */
422 	if (timinfo->id == 0 && timinfo->count < 20) {
423 		mytimer_reset(timinfo, hz, SINGLE, lcore_id, timer_basic_cb);
424 		return;
425 	}
426 
427 	/* reload timer 1 on next core */
428 	if (timinfo->id == 1 && timinfo->count < 10) {
429 		mytimer_reset(timinfo, hz*2, SINGLE,
430 			      rte_get_next_lcore(lcore_id, 0, 1),
431 			      timer_basic_cb);
432 		return;
433 	}
434 
435 	/* Explicitelly stop timer 0. Once stop() called, we can even
436 	 * erase the content of the structure: it is not referenced
437 	 * anymore by any code (in case of dynamic structure, it can
438 	 * be freed) */
439 	if (timinfo->id == 0 && timinfo->count == 20) {
440 
441 		/* stop_sync() is not needed, because we know that the
442 		 * status of timer is only modified by this core */
443 		rte_timer_stop(tim);
444 		memset(tim, 0xAA, sizeof(struct rte_timer));
445 		return;
446 	}
447 
448 	/* stop timer3, and restart a new timer0 (it was removed 5
449 	 * seconds ago) for a single shot */
450 	if (timinfo->id == 2 && timinfo->count == 25) {
451 		rte_timer_stop_sync(&mytiminfo[3].tim);
452 
453 		/* need to reinit because structure was erased with 0xAA */
454 		rte_timer_init(&mytiminfo[0].tim);
455 		mytimer_reset(&mytiminfo[0], hz, SINGLE, lcore_id,
456 			      timer_basic_cb);
457 	}
458 }
459 
460 static int
461 timer_basic_main_loop(__rte_unused void *arg)
462 {
463 	uint64_t hz = rte_get_timer_hz();
464 	unsigned lcore_id = rte_lcore_id();
465 	uint64_t cur_time;
466 	int64_t diff = 0;
467 
468 	/* launch all timers on core 0 */
469 	if (lcore_id == rte_get_main_lcore()) {
470 		mytimer_reset(&mytiminfo[0], hz/4, SINGLE, lcore_id,
471 			      timer_basic_cb);
472 		mytimer_reset(&mytiminfo[1], hz/2, SINGLE, lcore_id,
473 			      timer_basic_cb);
474 		mytimer_reset(&mytiminfo[2], hz/4, PERIODICAL, lcore_id,
475 			      timer_basic_cb);
476 		mytimer_reset(&mytiminfo[3], hz/4, PERIODICAL,
477 			      rte_get_next_lcore(lcore_id, 0, 1),
478 			      timer_basic_cb);
479 	}
480 
481 	while (diff >= 0) {
482 
483 		/* call the timer handler on each core */
484 		rte_timer_manage();
485 
486 		/* simulate the processing of a packet
487 		 * (3 us = 6000 cycles at 2 Ghz) */
488 		rte_delay_us(3);
489 
490 		cur_time = rte_get_timer_cycles();
491 		diff = end_time - cur_time;
492 	}
493 	RTE_LOG(INFO, TESTTIMER, "core %u finished\n", lcore_id);
494 
495 	return 0;
496 }
497 
498 static int
499 timer_sanity_check(void)
500 {
501 #ifdef RTE_LIBEAL_USE_HPET
502 	if (eal_timer_source != EAL_TIMER_HPET) {
503 		printf("Not using HPET, can't sanity check timer sources\n");
504 		return 0;
505 	}
506 
507 	const uint64_t t_hz = rte_get_tsc_hz();
508 	const uint64_t h_hz = rte_get_hpet_hz();
509 	printf("Hertz values: TSC = %"PRIu64", HPET = %"PRIu64"\n", t_hz, h_hz);
510 
511 	const uint64_t tsc_start = rte_get_tsc_cycles();
512 	const uint64_t hpet_start = rte_get_hpet_cycles();
513 	rte_delay_ms(100); /* delay 1/10 second */
514 	const uint64_t tsc_end = rte_get_tsc_cycles();
515 	const uint64_t hpet_end = rte_get_hpet_cycles();
516 	printf("Measured cycles: TSC = %"PRIu64", HPET = %"PRIu64"\n",
517 			tsc_end-tsc_start, hpet_end-hpet_start);
518 
519 	const double tsc_time = (double)(tsc_end - tsc_start)/t_hz;
520 	const double hpet_time = (double)(hpet_end - hpet_start)/h_hz;
521 	/* get the percentage that the times differ by */
522 	const double time_diff = fabs(tsc_time - hpet_time)*100/tsc_time;
523 	printf("Measured time: TSC = %.4f, HPET = %.4f\n", tsc_time, hpet_time);
524 
525 	printf("Elapsed time measured by TSC and HPET differ by %f%%\n",
526 			time_diff);
527 	if (time_diff > 0.1) {
528 		printf("Error times differ by >0.1%%");
529 		return -1;
530 	}
531 #endif
532 	return 0;
533 }
534 
535 static int
536 test_timer(void)
537 {
538 	unsigned i;
539 	uint64_t cur_time;
540 	uint64_t hz;
541 
542 	if (rte_lcore_count() < 2) {
543 		printf("Not enough cores for timer_autotest, expecting at least 2\n");
544 		return TEST_SKIPPED;
545 	}
546 
547 	/* sanity check our timer sources and timer config values */
548 	if (timer_sanity_check() < 0) {
549 		printf("Timer sanity checks failed\n");
550 		return TEST_FAILED;
551 	}
552 
553 	/* init timer */
554 	for (i=0; i<NB_TIMER; i++) {
555 		memset(&mytiminfo[i], 0, sizeof(struct mytimerinfo));
556 		mytiminfo[i].id = i;
557 		rte_timer_init(&mytiminfo[i].tim);
558 	}
559 
560 	/* calculate the "end of test" time */
561 	cur_time = rte_get_timer_cycles();
562 	hz = rte_get_timer_hz();
563 	end_time = cur_time + (hz * TEST_DURATION_S);
564 
565 	/* start other cores */
566 	printf("Start timer stress tests\n");
567 	rte_eal_mp_remote_launch(timer_stress_main_loop, NULL, CALL_MAIN);
568 	rte_eal_mp_wait_lcore();
569 
570 	/* stop timer 0 used for stress test */
571 	rte_timer_stop_sync(&mytiminfo[0].tim);
572 
573 	/* run a second, slightly different set of stress tests */
574 	printf("\nStart timer stress tests 2\n");
575 	test_failed = 0;
576 	rte_eal_mp_remote_launch(timer_stress2_main_loop, NULL, CALL_MAIN);
577 	rte_eal_mp_wait_lcore();
578 	if (test_failed)
579 		return TEST_FAILED;
580 
581 	/* calculate the "end of test" time */
582 	cur_time = rte_get_timer_cycles();
583 	hz = rte_get_timer_hz();
584 	end_time = cur_time + (hz * TEST_DURATION_S);
585 
586 	/* start other cores */
587 	printf("\nStart timer basic tests\n");
588 	rte_eal_mp_remote_launch(timer_basic_main_loop, NULL, CALL_MAIN);
589 	rte_eal_mp_wait_lcore();
590 
591 	/* stop all timers */
592 	for (i=0; i<NB_TIMER; i++) {
593 		rte_timer_stop_sync(&mytiminfo[i].tim);
594 	}
595 
596 	rte_timer_dump_stats(stdout);
597 
598 	return TEST_SUCCESS;
599 }
600 
601 REGISTER_TEST_COMMAND(timer_autotest, test_timer);
602