xref: /linux/tools/perf/tests/switch-tracking.c (revision 9a379e77033f02c4a071891afdf0f0a01eff8ccb)
1 // SPDX-License-Identifier: GPL-2.0
2 #include <sys/time.h>
3 #include <sys/prctl.h>
4 #include <errno.h>
5 #include <time.h>
6 #include <stdlib.h>
7 
8 #include "parse-events.h"
9 #include "evlist.h"
10 #include "evsel.h"
11 #include "thread_map.h"
12 #include "cpumap.h"
13 #include "tests.h"
14 
15 static int spin_sleep(void)
16 {
17 	struct timeval start, now, diff, maxtime;
18 	struct timespec ts;
19 	int err, i;
20 
21 	maxtime.tv_sec = 0;
22 	maxtime.tv_usec = 50000;
23 
24 	err = gettimeofday(&start, NULL);
25 	if (err)
26 		return err;
27 
28 	/* Spin for 50ms */
29 	while (1) {
30 		for (i = 0; i < 1000; i++)
31 			barrier();
32 
33 		err = gettimeofday(&now, NULL);
34 		if (err)
35 			return err;
36 
37 		timersub(&now, &start, &diff);
38 		if (timercmp(&diff, &maxtime, > /* For checkpatch */))
39 			break;
40 	}
41 
42 	ts.tv_nsec = 50 * 1000 * 1000;
43 	ts.tv_sec = 0;
44 
45 	/* Sleep for 50ms */
46 	err = nanosleep(&ts, NULL);
47 	if (err == EINTR)
48 		err = 0;
49 
50 	return err;
51 }
52 
53 struct switch_tracking {
54 	struct perf_evsel *switch_evsel;
55 	struct perf_evsel *cycles_evsel;
56 	pid_t *tids;
57 	int nr_tids;
58 	int comm_seen[4];
59 	int cycles_before_comm_1;
60 	int cycles_between_comm_2_and_comm_3;
61 	int cycles_after_comm_4;
62 };
63 
64 static int check_comm(struct switch_tracking *switch_tracking,
65 		      union perf_event *event, const char *comm, int nr)
66 {
67 	if (event->header.type == PERF_RECORD_COMM &&
68 	    (pid_t)event->comm.pid == getpid() &&
69 	    (pid_t)event->comm.tid == getpid() &&
70 	    strcmp(event->comm.comm, comm) == 0) {
71 		if (switch_tracking->comm_seen[nr]) {
72 			pr_debug("Duplicate comm event\n");
73 			return -1;
74 		}
75 		switch_tracking->comm_seen[nr] = 1;
76 		pr_debug3("comm event: %s nr: %d\n", event->comm.comm, nr);
77 		return 1;
78 	}
79 	return 0;
80 }
81 
82 static int check_cpu(struct switch_tracking *switch_tracking, int cpu)
83 {
84 	int i, nr = cpu + 1;
85 
86 	if (cpu < 0)
87 		return -1;
88 
89 	if (!switch_tracking->tids) {
90 		switch_tracking->tids = calloc(nr, sizeof(pid_t));
91 		if (!switch_tracking->tids)
92 			return -1;
93 		for (i = 0; i < nr; i++)
94 			switch_tracking->tids[i] = -1;
95 		switch_tracking->nr_tids = nr;
96 		return 0;
97 	}
98 
99 	if (cpu >= switch_tracking->nr_tids) {
100 		void *addr;
101 
102 		addr = realloc(switch_tracking->tids, nr * sizeof(pid_t));
103 		if (!addr)
104 			return -1;
105 		switch_tracking->tids = addr;
106 		for (i = switch_tracking->nr_tids; i < nr; i++)
107 			switch_tracking->tids[i] = -1;
108 		switch_tracking->nr_tids = nr;
109 		return 0;
110 	}
111 
112 	return 0;
113 }
114 
115 static int process_sample_event(struct perf_evlist *evlist,
116 				union perf_event *event,
117 				struct switch_tracking *switch_tracking)
118 {
119 	struct perf_sample sample;
120 	struct perf_evsel *evsel;
121 	pid_t next_tid, prev_tid;
122 	int cpu, err;
123 
124 	if (perf_evlist__parse_sample(evlist, event, &sample)) {
125 		pr_debug("perf_evlist__parse_sample failed\n");
126 		return -1;
127 	}
128 
129 	evsel = perf_evlist__id2evsel(evlist, sample.id);
130 	if (evsel == switch_tracking->switch_evsel) {
131 		next_tid = perf_evsel__intval(evsel, &sample, "next_pid");
132 		prev_tid = perf_evsel__intval(evsel, &sample, "prev_pid");
133 		cpu = sample.cpu;
134 		pr_debug3("sched_switch: cpu: %d prev_tid %d next_tid %d\n",
135 			  cpu, prev_tid, next_tid);
136 		err = check_cpu(switch_tracking, cpu);
137 		if (err)
138 			return err;
139 		/*
140 		 * Check for no missing sched_switch events i.e. that the
141 		 * evsel->system_wide flag has worked.
142 		 */
143 		if (switch_tracking->tids[cpu] != -1 &&
144 		    switch_tracking->tids[cpu] != prev_tid) {
145 			pr_debug("Missing sched_switch events\n");
146 			return -1;
147 		}
148 		switch_tracking->tids[cpu] = next_tid;
149 	}
150 
151 	if (evsel == switch_tracking->cycles_evsel) {
152 		pr_debug3("cycles event\n");
153 		if (!switch_tracking->comm_seen[0])
154 			switch_tracking->cycles_before_comm_1 = 1;
155 		if (switch_tracking->comm_seen[1] &&
156 		    !switch_tracking->comm_seen[2])
157 			switch_tracking->cycles_between_comm_2_and_comm_3 = 1;
158 		if (switch_tracking->comm_seen[3])
159 			switch_tracking->cycles_after_comm_4 = 1;
160 	}
161 
162 	return 0;
163 }
164 
165 static int process_event(struct perf_evlist *evlist, union perf_event *event,
166 			 struct switch_tracking *switch_tracking)
167 {
168 	if (event->header.type == PERF_RECORD_SAMPLE)
169 		return process_sample_event(evlist, event, switch_tracking);
170 
171 	if (event->header.type == PERF_RECORD_COMM) {
172 		int err, done = 0;
173 
174 		err = check_comm(switch_tracking, event, "Test COMM 1", 0);
175 		if (err < 0)
176 			return -1;
177 		done += err;
178 		err = check_comm(switch_tracking, event, "Test COMM 2", 1);
179 		if (err < 0)
180 			return -1;
181 		done += err;
182 		err = check_comm(switch_tracking, event, "Test COMM 3", 2);
183 		if (err < 0)
184 			return -1;
185 		done += err;
186 		err = check_comm(switch_tracking, event, "Test COMM 4", 3);
187 		if (err < 0)
188 			return -1;
189 		done += err;
190 		if (done != 1) {
191 			pr_debug("Unexpected comm event\n");
192 			return -1;
193 		}
194 	}
195 
196 	return 0;
197 }
198 
199 struct event_node {
200 	struct list_head list;
201 	union perf_event *event;
202 	u64 event_time;
203 };
204 
205 static int add_event(struct perf_evlist *evlist, struct list_head *events,
206 		     union perf_event *event)
207 {
208 	struct perf_sample sample;
209 	struct event_node *node;
210 
211 	node = malloc(sizeof(struct event_node));
212 	if (!node) {
213 		pr_debug("malloc failed\n");
214 		return -1;
215 	}
216 	node->event = event;
217 	list_add(&node->list, events);
218 
219 	if (perf_evlist__parse_sample(evlist, event, &sample)) {
220 		pr_debug("perf_evlist__parse_sample failed\n");
221 		return -1;
222 	}
223 
224 	if (!sample.time) {
225 		pr_debug("event with no time\n");
226 		return -1;
227 	}
228 
229 	node->event_time = sample.time;
230 
231 	return 0;
232 }
233 
234 static void free_event_nodes(struct list_head *events)
235 {
236 	struct event_node *node;
237 
238 	while (!list_empty(events)) {
239 		node = list_entry(events->next, struct event_node, list);
240 		list_del(&node->list);
241 		free(node);
242 	}
243 }
244 
245 static int compar(const void *a, const void *b)
246 {
247 	const struct event_node *nodea = a;
248 	const struct event_node *nodeb = b;
249 	s64 cmp = nodea->event_time - nodeb->event_time;
250 
251 	return cmp;
252 }
253 
254 static int process_events(struct perf_evlist *evlist,
255 			  struct switch_tracking *switch_tracking)
256 {
257 	union perf_event *event;
258 	unsigned pos, cnt = 0;
259 	LIST_HEAD(events);
260 	struct event_node *events_array, *node;
261 	int i, ret;
262 
263 	for (i = 0; i < evlist->nr_mmaps; i++) {
264 		while ((event = perf_evlist__mmap_read(evlist, i)) != NULL) {
265 			cnt += 1;
266 			ret = add_event(evlist, &events, event);
267 			perf_evlist__mmap_consume(evlist, i);
268 			if (ret < 0)
269 				goto out_free_nodes;
270 		}
271 	}
272 
273 	events_array = calloc(cnt, sizeof(struct event_node));
274 	if (!events_array) {
275 		pr_debug("calloc failed\n");
276 		ret = -1;
277 		goto out_free_nodes;
278 	}
279 
280 	pos = 0;
281 	list_for_each_entry(node, &events, list)
282 		events_array[pos++] = *node;
283 
284 	qsort(events_array, cnt, sizeof(struct event_node), compar);
285 
286 	for (pos = 0; pos < cnt; pos++) {
287 		ret = process_event(evlist, events_array[pos].event,
288 				    switch_tracking);
289 		if (ret < 0)
290 			goto out_free;
291 	}
292 
293 	ret = 0;
294 out_free:
295 	pr_debug("%u events recorded\n", cnt);
296 	free(events_array);
297 out_free_nodes:
298 	free_event_nodes(&events);
299 	return ret;
300 }
301 
302 /**
303  * test__switch_tracking - test using sched_switch and tracking events.
304  *
305  * This function implements a test that checks that sched_switch events and
306  * tracking events can be recorded for a workload (current process) using the
307  * evsel->system_wide and evsel->tracking flags (respectively) with other events
308  * sometimes enabled or disabled.
309  */
310 int test__switch_tracking(struct test *test __maybe_unused, int subtest __maybe_unused)
311 {
312 	const char *sched_switch = "sched:sched_switch";
313 	struct switch_tracking switch_tracking = { .tids = NULL, };
314 	struct record_opts opts = {
315 		.mmap_pages	     = UINT_MAX,
316 		.user_freq	     = UINT_MAX,
317 		.user_interval	     = ULLONG_MAX,
318 		.freq		     = 4000,
319 		.target		     = {
320 			.uses_mmap   = true,
321 		},
322 	};
323 	struct thread_map *threads = NULL;
324 	struct cpu_map *cpus = NULL;
325 	struct perf_evlist *evlist = NULL;
326 	struct perf_evsel *evsel, *cpu_clocks_evsel, *cycles_evsel;
327 	struct perf_evsel *switch_evsel, *tracking_evsel;
328 	const char *comm;
329 	int err = -1;
330 
331 	threads = thread_map__new(-1, getpid(), UINT_MAX);
332 	if (!threads) {
333 		pr_debug("thread_map__new failed!\n");
334 		goto out_err;
335 	}
336 
337 	cpus = cpu_map__new(NULL);
338 	if (!cpus) {
339 		pr_debug("cpu_map__new failed!\n");
340 		goto out_err;
341 	}
342 
343 	evlist = perf_evlist__new();
344 	if (!evlist) {
345 		pr_debug("perf_evlist__new failed!\n");
346 		goto out_err;
347 	}
348 
349 	perf_evlist__set_maps(evlist, cpus, threads);
350 
351 	/* First event */
352 	err = parse_events(evlist, "cpu-clock:u", NULL);
353 	if (err) {
354 		pr_debug("Failed to parse event dummy:u\n");
355 		goto out_err;
356 	}
357 
358 	cpu_clocks_evsel = perf_evlist__last(evlist);
359 
360 	/* Second event */
361 	err = parse_events(evlist, "cycles:u", NULL);
362 	if (err) {
363 		pr_debug("Failed to parse event cycles:u\n");
364 		goto out_err;
365 	}
366 
367 	cycles_evsel = perf_evlist__last(evlist);
368 
369 	/* Third event */
370 	if (!perf_evlist__can_select_event(evlist, sched_switch)) {
371 		pr_debug("No sched_switch\n");
372 		err = 0;
373 		goto out;
374 	}
375 
376 	err = parse_events(evlist, sched_switch, NULL);
377 	if (err) {
378 		pr_debug("Failed to parse event %s\n", sched_switch);
379 		goto out_err;
380 	}
381 
382 	switch_evsel = perf_evlist__last(evlist);
383 
384 	perf_evsel__set_sample_bit(switch_evsel, CPU);
385 	perf_evsel__set_sample_bit(switch_evsel, TIME);
386 
387 	switch_evsel->system_wide = true;
388 	switch_evsel->no_aux_samples = true;
389 	switch_evsel->immediate = true;
390 
391 	/* Test moving an event to the front */
392 	if (cycles_evsel == perf_evlist__first(evlist)) {
393 		pr_debug("cycles event already at front");
394 		goto out_err;
395 	}
396 	perf_evlist__to_front(evlist, cycles_evsel);
397 	if (cycles_evsel != perf_evlist__first(evlist)) {
398 		pr_debug("Failed to move cycles event to front");
399 		goto out_err;
400 	}
401 
402 	perf_evsel__set_sample_bit(cycles_evsel, CPU);
403 	perf_evsel__set_sample_bit(cycles_evsel, TIME);
404 
405 	/* Fourth event */
406 	err = parse_events(evlist, "dummy:u", NULL);
407 	if (err) {
408 		pr_debug("Failed to parse event dummy:u\n");
409 		goto out_err;
410 	}
411 
412 	tracking_evsel = perf_evlist__last(evlist);
413 
414 	perf_evlist__set_tracking_event(evlist, tracking_evsel);
415 
416 	tracking_evsel->attr.freq = 0;
417 	tracking_evsel->attr.sample_period = 1;
418 
419 	perf_evsel__set_sample_bit(tracking_evsel, TIME);
420 
421 	/* Config events */
422 	perf_evlist__config(evlist, &opts, NULL);
423 
424 	/* Check moved event is still at the front */
425 	if (cycles_evsel != perf_evlist__first(evlist)) {
426 		pr_debug("Front event no longer at front");
427 		goto out_err;
428 	}
429 
430 	/* Check tracking event is tracking */
431 	if (!tracking_evsel->attr.mmap || !tracking_evsel->attr.comm) {
432 		pr_debug("Tracking event not tracking\n");
433 		goto out_err;
434 	}
435 
436 	/* Check non-tracking events are not tracking */
437 	evlist__for_each_entry(evlist, evsel) {
438 		if (evsel != tracking_evsel) {
439 			if (evsel->attr.mmap || evsel->attr.comm) {
440 				pr_debug("Non-tracking event is tracking\n");
441 				goto out_err;
442 			}
443 		}
444 	}
445 
446 	if (perf_evlist__open(evlist) < 0) {
447 		pr_debug("Not supported\n");
448 		err = 0;
449 		goto out;
450 	}
451 
452 	err = perf_evlist__mmap(evlist, UINT_MAX);
453 	if (err) {
454 		pr_debug("perf_evlist__mmap failed!\n");
455 		goto out_err;
456 	}
457 
458 	perf_evlist__enable(evlist);
459 
460 	err = perf_evsel__disable(cpu_clocks_evsel);
461 	if (err) {
462 		pr_debug("perf_evlist__disable_event failed!\n");
463 		goto out_err;
464 	}
465 
466 	err = spin_sleep();
467 	if (err) {
468 		pr_debug("spin_sleep failed!\n");
469 		goto out_err;
470 	}
471 
472 	comm = "Test COMM 1";
473 	err = prctl(PR_SET_NAME, (unsigned long)comm, 0, 0, 0);
474 	if (err) {
475 		pr_debug("PR_SET_NAME failed!\n");
476 		goto out_err;
477 	}
478 
479 	err = perf_evsel__disable(cycles_evsel);
480 	if (err) {
481 		pr_debug("perf_evlist__disable_event failed!\n");
482 		goto out_err;
483 	}
484 
485 	comm = "Test COMM 2";
486 	err = prctl(PR_SET_NAME, (unsigned long)comm, 0, 0, 0);
487 	if (err) {
488 		pr_debug("PR_SET_NAME failed!\n");
489 		goto out_err;
490 	}
491 
492 	err = spin_sleep();
493 	if (err) {
494 		pr_debug("spin_sleep failed!\n");
495 		goto out_err;
496 	}
497 
498 	comm = "Test COMM 3";
499 	err = prctl(PR_SET_NAME, (unsigned long)comm, 0, 0, 0);
500 	if (err) {
501 		pr_debug("PR_SET_NAME failed!\n");
502 		goto out_err;
503 	}
504 
505 	err = perf_evsel__enable(cycles_evsel);
506 	if (err) {
507 		pr_debug("perf_evlist__disable_event failed!\n");
508 		goto out_err;
509 	}
510 
511 	comm = "Test COMM 4";
512 	err = prctl(PR_SET_NAME, (unsigned long)comm, 0, 0, 0);
513 	if (err) {
514 		pr_debug("PR_SET_NAME failed!\n");
515 		goto out_err;
516 	}
517 
518 	err = spin_sleep();
519 	if (err) {
520 		pr_debug("spin_sleep failed!\n");
521 		goto out_err;
522 	}
523 
524 	perf_evlist__disable(evlist);
525 
526 	switch_tracking.switch_evsel = switch_evsel;
527 	switch_tracking.cycles_evsel = cycles_evsel;
528 
529 	err = process_events(evlist, &switch_tracking);
530 
531 	zfree(&switch_tracking.tids);
532 
533 	if (err)
534 		goto out_err;
535 
536 	/* Check all 4 comm events were seen i.e. that evsel->tracking works */
537 	if (!switch_tracking.comm_seen[0] || !switch_tracking.comm_seen[1] ||
538 	    !switch_tracking.comm_seen[2] || !switch_tracking.comm_seen[3]) {
539 		pr_debug("Missing comm events\n");
540 		goto out_err;
541 	}
542 
543 	/* Check cycles event got enabled */
544 	if (!switch_tracking.cycles_before_comm_1) {
545 		pr_debug("Missing cycles events\n");
546 		goto out_err;
547 	}
548 
549 	/* Check cycles event got disabled */
550 	if (switch_tracking.cycles_between_comm_2_and_comm_3) {
551 		pr_debug("cycles events even though event was disabled\n");
552 		goto out_err;
553 	}
554 
555 	/* Check cycles event got enabled again */
556 	if (!switch_tracking.cycles_after_comm_4) {
557 		pr_debug("Missing cycles events\n");
558 		goto out_err;
559 	}
560 out:
561 	if (evlist) {
562 		perf_evlist__disable(evlist);
563 		perf_evlist__delete(evlist);
564 	} else {
565 		cpu_map__put(cpus);
566 		thread_map__put(threads);
567 	}
568 
569 	return err;
570 
571 out_err:
572 	err = -1;
573 	goto out;
574 }
575