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1 #include <sys/time.h>
2 #include <sys/prctl.h>
3 #include <time.h>
4 #include <stdlib.h>
5 
6 #include "parse-events.h"
7 #include "evlist.h"
8 #include "evsel.h"
9 #include "thread_map.h"
10 #include "cpumap.h"
11 #include "tests.h"
12 
spin_sleep(void)13 static int spin_sleep(void)
14 {
15 	struct timeval start, now, diff, maxtime;
16 	struct timespec ts;
17 	int err, i;
18 
19 	maxtime.tv_sec = 0;
20 	maxtime.tv_usec = 50000;
21 
22 	err = gettimeofday(&start, NULL);
23 	if (err)
24 		return err;
25 
26 	/* Spin for 50ms */
27 	while (1) {
28 		for (i = 0; i < 1000; i++)
29 			barrier();
30 
31 		err = gettimeofday(&now, NULL);
32 		if (err)
33 			return err;
34 
35 		timersub(&now, &start, &diff);
36 		if (timercmp(&diff, &maxtime, > /* For checkpatch */))
37 			break;
38 	}
39 
40 	ts.tv_nsec = 50 * 1000 * 1000;
41 	ts.tv_sec = 0;
42 
43 	/* Sleep for 50ms */
44 	err = nanosleep(&ts, NULL);
45 	if (err == EINTR)
46 		err = 0;
47 
48 	return err;
49 }
50 
51 struct switch_tracking {
52 	struct perf_evsel *switch_evsel;
53 	struct perf_evsel *cycles_evsel;
54 	pid_t *tids;
55 	int nr_tids;
56 	int comm_seen[4];
57 	int cycles_before_comm_1;
58 	int cycles_between_comm_2_and_comm_3;
59 	int cycles_after_comm_4;
60 };
61 
check_comm(struct switch_tracking * switch_tracking,union perf_event * event,const char * comm,int nr)62 static int check_comm(struct switch_tracking *switch_tracking,
63 		      union perf_event *event, const char *comm, int nr)
64 {
65 	if (event->header.type == PERF_RECORD_COMM &&
66 	    (pid_t)event->comm.pid == getpid() &&
67 	    (pid_t)event->comm.tid == getpid() &&
68 	    strcmp(event->comm.comm, comm) == 0) {
69 		if (switch_tracking->comm_seen[nr]) {
70 			pr_debug("Duplicate comm event\n");
71 			return -1;
72 		}
73 		switch_tracking->comm_seen[nr] = 1;
74 		pr_debug3("comm event: %s nr: %d\n", event->comm.comm, nr);
75 		return 1;
76 	}
77 	return 0;
78 }
79 
check_cpu(struct switch_tracking * switch_tracking,int cpu)80 static int check_cpu(struct switch_tracking *switch_tracking, int cpu)
81 {
82 	int i, nr = cpu + 1;
83 
84 	if (cpu < 0)
85 		return -1;
86 
87 	if (!switch_tracking->tids) {
88 		switch_tracking->tids = calloc(nr, sizeof(pid_t));
89 		if (!switch_tracking->tids)
90 			return -1;
91 		for (i = 0; i < nr; i++)
92 			switch_tracking->tids[i] = -1;
93 		switch_tracking->nr_tids = nr;
94 		return 0;
95 	}
96 
97 	if (cpu >= switch_tracking->nr_tids) {
98 		void *addr;
99 
100 		addr = realloc(switch_tracking->tids, nr * sizeof(pid_t));
101 		if (!addr)
102 			return -1;
103 		switch_tracking->tids = addr;
104 		for (i = switch_tracking->nr_tids; i < nr; i++)
105 			switch_tracking->tids[i] = -1;
106 		switch_tracking->nr_tids = nr;
107 		return 0;
108 	}
109 
110 	return 0;
111 }
112 
process_sample_event(struct perf_evlist * evlist,union perf_event * event,struct switch_tracking * switch_tracking)113 static int process_sample_event(struct perf_evlist *evlist,
114 				union perf_event *event,
115 				struct switch_tracking *switch_tracking)
116 {
117 	struct perf_sample sample;
118 	struct perf_evsel *evsel;
119 	pid_t next_tid, prev_tid;
120 	int cpu, err;
121 
122 	if (perf_evlist__parse_sample(evlist, event, &sample)) {
123 		pr_debug("perf_evlist__parse_sample failed\n");
124 		return -1;
125 	}
126 
127 	evsel = perf_evlist__id2evsel(evlist, sample.id);
128 	if (evsel == switch_tracking->switch_evsel) {
129 		next_tid = perf_evsel__intval(evsel, &sample, "next_pid");
130 		prev_tid = perf_evsel__intval(evsel, &sample, "prev_pid");
131 		cpu = sample.cpu;
132 		pr_debug3("sched_switch: cpu: %d prev_tid %d next_tid %d\n",
133 			  cpu, prev_tid, next_tid);
134 		err = check_cpu(switch_tracking, cpu);
135 		if (err)
136 			return err;
137 		/*
138 		 * Check for no missing sched_switch events i.e. that the
139 		 * evsel->system_wide flag has worked.
140 		 */
141 		if (switch_tracking->tids[cpu] != -1 &&
142 		    switch_tracking->tids[cpu] != prev_tid) {
143 			pr_debug("Missing sched_switch events\n");
144 			return -1;
145 		}
146 		switch_tracking->tids[cpu] = next_tid;
147 	}
148 
149 	if (evsel == switch_tracking->cycles_evsel) {
150 		pr_debug3("cycles event\n");
151 		if (!switch_tracking->comm_seen[0])
152 			switch_tracking->cycles_before_comm_1 = 1;
153 		if (switch_tracking->comm_seen[1] &&
154 		    !switch_tracking->comm_seen[2])
155 			switch_tracking->cycles_between_comm_2_and_comm_3 = 1;
156 		if (switch_tracking->comm_seen[3])
157 			switch_tracking->cycles_after_comm_4 = 1;
158 	}
159 
160 	return 0;
161 }
162 
process_event(struct perf_evlist * evlist,union perf_event * event,struct switch_tracking * switch_tracking)163 static int process_event(struct perf_evlist *evlist, union perf_event *event,
164 			 struct switch_tracking *switch_tracking)
165 {
166 	if (event->header.type == PERF_RECORD_SAMPLE)
167 		return process_sample_event(evlist, event, switch_tracking);
168 
169 	if (event->header.type == PERF_RECORD_COMM) {
170 		int err, done = 0;
171 
172 		err = check_comm(switch_tracking, event, "Test COMM 1", 0);
173 		if (err < 0)
174 			return -1;
175 		done += err;
176 		err = check_comm(switch_tracking, event, "Test COMM 2", 1);
177 		if (err < 0)
178 			return -1;
179 		done += err;
180 		err = check_comm(switch_tracking, event, "Test COMM 3", 2);
181 		if (err < 0)
182 			return -1;
183 		done += err;
184 		err = check_comm(switch_tracking, event, "Test COMM 4", 3);
185 		if (err < 0)
186 			return -1;
187 		done += err;
188 		if (done != 1) {
189 			pr_debug("Unexpected comm event\n");
190 			return -1;
191 		}
192 	}
193 
194 	return 0;
195 }
196 
197 struct event_node {
198 	struct list_head list;
199 	union perf_event *event;
200 	u64 event_time;
201 };
202 
add_event(struct perf_evlist * evlist,struct list_head * events,union perf_event * event)203 static int add_event(struct perf_evlist *evlist, struct list_head *events,
204 		     union perf_event *event)
205 {
206 	struct perf_sample sample;
207 	struct event_node *node;
208 
209 	node = malloc(sizeof(struct event_node));
210 	if (!node) {
211 		pr_debug("malloc failed\n");
212 		return -1;
213 	}
214 	node->event = event;
215 	list_add(&node->list, events);
216 
217 	if (perf_evlist__parse_sample(evlist, event, &sample)) {
218 		pr_debug("perf_evlist__parse_sample failed\n");
219 		return -1;
220 	}
221 
222 	if (!sample.time) {
223 		pr_debug("event with no time\n");
224 		return -1;
225 	}
226 
227 	node->event_time = sample.time;
228 
229 	return 0;
230 }
231 
free_event_nodes(struct list_head * events)232 static void free_event_nodes(struct list_head *events)
233 {
234 	struct event_node *node;
235 
236 	while (!list_empty(events)) {
237 		node = list_entry(events->next, struct event_node, list);
238 		list_del(&node->list);
239 		free(node);
240 	}
241 }
242 
compar(const void * a,const void * b)243 static int compar(const void *a, const void *b)
244 {
245 	const struct event_node *nodea = a;
246 	const struct event_node *nodeb = b;
247 	s64 cmp = nodea->event_time - nodeb->event_time;
248 
249 	return cmp;
250 }
251 
process_events(struct perf_evlist * evlist,struct switch_tracking * switch_tracking)252 static int process_events(struct perf_evlist *evlist,
253 			  struct switch_tracking *switch_tracking)
254 {
255 	union perf_event *event;
256 	unsigned pos, cnt = 0;
257 	LIST_HEAD(events);
258 	struct event_node *events_array, *node;
259 	int i, ret;
260 
261 	for (i = 0; i < evlist->nr_mmaps; i++) {
262 		while ((event = perf_evlist__mmap_read(evlist, i)) != NULL) {
263 			cnt += 1;
264 			ret = add_event(evlist, &events, event);
265 			perf_evlist__mmap_consume(evlist, i);
266 			if (ret < 0)
267 				goto out_free_nodes;
268 		}
269 	}
270 
271 	events_array = calloc(cnt, sizeof(struct event_node));
272 	if (!events_array) {
273 		pr_debug("calloc failed\n");
274 		ret = -1;
275 		goto out_free_nodes;
276 	}
277 
278 	pos = 0;
279 	list_for_each_entry(node, &events, list)
280 		events_array[pos++] = *node;
281 
282 	qsort(events_array, cnt, sizeof(struct event_node), compar);
283 
284 	for (pos = 0; pos < cnt; pos++) {
285 		ret = process_event(evlist, events_array[pos].event,
286 				    switch_tracking);
287 		if (ret < 0)
288 			goto out_free;
289 	}
290 
291 	ret = 0;
292 out_free:
293 	pr_debug("%u events recorded\n", cnt);
294 	free(events_array);
295 out_free_nodes:
296 	free_event_nodes(&events);
297 	return ret;
298 }
299 
300 /**
301  * test__switch_tracking - test using sched_switch and tracking events.
302  *
303  * This function implements a test that checks that sched_switch events and
304  * tracking events can be recorded for a workload (current process) using the
305  * evsel->system_wide and evsel->tracking flags (respectively) with other events
306  * sometimes enabled or disabled.
307  */
test__switch_tracking(void)308 int test__switch_tracking(void)
309 {
310 	const char *sched_switch = "sched:sched_switch";
311 	struct switch_tracking switch_tracking = { .tids = NULL, };
312 	struct record_opts opts = {
313 		.mmap_pages	     = UINT_MAX,
314 		.user_freq	     = UINT_MAX,
315 		.user_interval	     = ULLONG_MAX,
316 		.freq		     = 4000,
317 		.target		     = {
318 			.uses_mmap   = true,
319 		},
320 	};
321 	struct thread_map *threads = NULL;
322 	struct cpu_map *cpus = NULL;
323 	struct perf_evlist *evlist = NULL;
324 	struct perf_evsel *evsel, *cpu_clocks_evsel, *cycles_evsel;
325 	struct perf_evsel *switch_evsel, *tracking_evsel;
326 	const char *comm;
327 	int err = -1;
328 
329 	threads = thread_map__new(-1, getpid(), UINT_MAX);
330 	if (!threads) {
331 		pr_debug("thread_map__new failed!\n");
332 		goto out_err;
333 	}
334 
335 	cpus = cpu_map__new(NULL);
336 	if (!cpus) {
337 		pr_debug("cpu_map__new failed!\n");
338 		goto out_err;
339 	}
340 
341 	evlist = perf_evlist__new();
342 	if (!evlist) {
343 		pr_debug("perf_evlist__new failed!\n");
344 		goto out_err;
345 	}
346 
347 	perf_evlist__set_maps(evlist, cpus, threads);
348 
349 	/* First event */
350 	err = parse_events(evlist, "cpu-clock:u", NULL);
351 	if (err) {
352 		pr_debug("Failed to parse event dummy:u\n");
353 		goto out_err;
354 	}
355 
356 	cpu_clocks_evsel = perf_evlist__last(evlist);
357 
358 	/* Second event */
359 	err = parse_events(evlist, "cycles:u", NULL);
360 	if (err) {
361 		pr_debug("Failed to parse event cycles:u\n");
362 		goto out_err;
363 	}
364 
365 	cycles_evsel = perf_evlist__last(evlist);
366 
367 	/* Third event */
368 	if (!perf_evlist__can_select_event(evlist, sched_switch)) {
369 		pr_debug("No sched_switch\n");
370 		err = 0;
371 		goto out;
372 	}
373 
374 	err = parse_events(evlist, sched_switch, NULL);
375 	if (err) {
376 		pr_debug("Failed to parse event %s\n", sched_switch);
377 		goto out_err;
378 	}
379 
380 	switch_evsel = perf_evlist__last(evlist);
381 
382 	perf_evsel__set_sample_bit(switch_evsel, CPU);
383 	perf_evsel__set_sample_bit(switch_evsel, TIME);
384 
385 	switch_evsel->system_wide = true;
386 	switch_evsel->no_aux_samples = true;
387 	switch_evsel->immediate = true;
388 
389 	/* Test moving an event to the front */
390 	if (cycles_evsel == perf_evlist__first(evlist)) {
391 		pr_debug("cycles event already at front");
392 		goto out_err;
393 	}
394 	perf_evlist__to_front(evlist, cycles_evsel);
395 	if (cycles_evsel != perf_evlist__first(evlist)) {
396 		pr_debug("Failed to move cycles event to front");
397 		goto out_err;
398 	}
399 
400 	perf_evsel__set_sample_bit(cycles_evsel, CPU);
401 	perf_evsel__set_sample_bit(cycles_evsel, TIME);
402 
403 	/* Fourth event */
404 	err = parse_events(evlist, "dummy:u", NULL);
405 	if (err) {
406 		pr_debug("Failed to parse event dummy:u\n");
407 		goto out_err;
408 	}
409 
410 	tracking_evsel = perf_evlist__last(evlist);
411 
412 	perf_evlist__set_tracking_event(evlist, tracking_evsel);
413 
414 	tracking_evsel->attr.freq = 0;
415 	tracking_evsel->attr.sample_period = 1;
416 
417 	perf_evsel__set_sample_bit(tracking_evsel, TIME);
418 
419 	/* Config events */
420 	perf_evlist__config(evlist, &opts);
421 
422 	/* Check moved event is still at the front */
423 	if (cycles_evsel != perf_evlist__first(evlist)) {
424 		pr_debug("Front event no longer at front");
425 		goto out_err;
426 	}
427 
428 	/* Check tracking event is tracking */
429 	if (!tracking_evsel->attr.mmap || !tracking_evsel->attr.comm) {
430 		pr_debug("Tracking event not tracking\n");
431 		goto out_err;
432 	}
433 
434 	/* Check non-tracking events are not tracking */
435 	evlist__for_each(evlist, evsel) {
436 		if (evsel != tracking_evsel) {
437 			if (evsel->attr.mmap || evsel->attr.comm) {
438 				pr_debug("Non-tracking event is tracking\n");
439 				goto out_err;
440 			}
441 		}
442 	}
443 
444 	if (perf_evlist__open(evlist) < 0) {
445 		pr_debug("Not supported\n");
446 		err = 0;
447 		goto out;
448 	}
449 
450 	err = perf_evlist__mmap(evlist, UINT_MAX, false);
451 	if (err) {
452 		pr_debug("perf_evlist__mmap failed!\n");
453 		goto out_err;
454 	}
455 
456 	perf_evlist__enable(evlist);
457 
458 	err = perf_evlist__disable_event(evlist, cpu_clocks_evsel);
459 	if (err) {
460 		pr_debug("perf_evlist__disable_event failed!\n");
461 		goto out_err;
462 	}
463 
464 	err = spin_sleep();
465 	if (err) {
466 		pr_debug("spin_sleep failed!\n");
467 		goto out_err;
468 	}
469 
470 	comm = "Test COMM 1";
471 	err = prctl(PR_SET_NAME, (unsigned long)comm, 0, 0, 0);
472 	if (err) {
473 		pr_debug("PR_SET_NAME failed!\n");
474 		goto out_err;
475 	}
476 
477 	err = perf_evlist__disable_event(evlist, cycles_evsel);
478 	if (err) {
479 		pr_debug("perf_evlist__disable_event failed!\n");
480 		goto out_err;
481 	}
482 
483 	comm = "Test COMM 2";
484 	err = prctl(PR_SET_NAME, (unsigned long)comm, 0, 0, 0);
485 	if (err) {
486 		pr_debug("PR_SET_NAME failed!\n");
487 		goto out_err;
488 	}
489 
490 	err = spin_sleep();
491 	if (err) {
492 		pr_debug("spin_sleep failed!\n");
493 		goto out_err;
494 	}
495 
496 	comm = "Test COMM 3";
497 	err = prctl(PR_SET_NAME, (unsigned long)comm, 0, 0, 0);
498 	if (err) {
499 		pr_debug("PR_SET_NAME failed!\n");
500 		goto out_err;
501 	}
502 
503 	err = perf_evlist__enable_event(evlist, cycles_evsel);
504 	if (err) {
505 		pr_debug("perf_evlist__disable_event failed!\n");
506 		goto out_err;
507 	}
508 
509 	comm = "Test COMM 4";
510 	err = prctl(PR_SET_NAME, (unsigned long)comm, 0, 0, 0);
511 	if (err) {
512 		pr_debug("PR_SET_NAME failed!\n");
513 		goto out_err;
514 	}
515 
516 	err = spin_sleep();
517 	if (err) {
518 		pr_debug("spin_sleep failed!\n");
519 		goto out_err;
520 	}
521 
522 	perf_evlist__disable(evlist);
523 
524 	switch_tracking.switch_evsel = switch_evsel;
525 	switch_tracking.cycles_evsel = cycles_evsel;
526 
527 	err = process_events(evlist, &switch_tracking);
528 
529 	zfree(&switch_tracking.tids);
530 
531 	if (err)
532 		goto out_err;
533 
534 	/* Check all 4 comm events were seen i.e. that evsel->tracking works */
535 	if (!switch_tracking.comm_seen[0] || !switch_tracking.comm_seen[1] ||
536 	    !switch_tracking.comm_seen[2] || !switch_tracking.comm_seen[3]) {
537 		pr_debug("Missing comm events\n");
538 		goto out_err;
539 	}
540 
541 	/* Check cycles event got enabled */
542 	if (!switch_tracking.cycles_before_comm_1) {
543 		pr_debug("Missing cycles events\n");
544 		goto out_err;
545 	}
546 
547 	/* Check cycles event got disabled */
548 	if (switch_tracking.cycles_between_comm_2_and_comm_3) {
549 		pr_debug("cycles events even though event was disabled\n");
550 		goto out_err;
551 	}
552 
553 	/* Check cycles event got enabled again */
554 	if (!switch_tracking.cycles_after_comm_4) {
555 		pr_debug("Missing cycles events\n");
556 		goto out_err;
557 	}
558 out:
559 	if (evlist) {
560 		perf_evlist__disable(evlist);
561 		perf_evlist__delete(evlist);
562 	} else {
563 		cpu_map__put(cpus);
564 		thread_map__put(threads);
565 	}
566 
567 	return err;
568 
569 out_err:
570 	err = -1;
571 	goto out;
572 }
573