xref: /linux/tools/perf/tests/switch-tracking.c (revision 8520a98dbab61e9e340cdfb72dd17ccc8a98961e)
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 #include <linux/zalloc.h>
8 #include <perf/cpumap.h>
9 #include <perf/evlist.h>
10 
11 #include "debug.h"
12 #include "parse-events.h"
13 #include "evlist.h"
14 #include "evsel.h"
15 #include "thread_map.h"
16 #include "cpumap.h"
17 #include "record.h"
18 #include "tests.h"
19 
20 static int spin_sleep(void)
21 {
22 	struct timeval start, now, diff, maxtime;
23 	struct timespec ts;
24 	int err, i;
25 
26 	maxtime.tv_sec = 0;
27 	maxtime.tv_usec = 50000;
28 
29 	err = gettimeofday(&start, NULL);
30 	if (err)
31 		return err;
32 
33 	/* Spin for 50ms */
34 	while (1) {
35 		for (i = 0; i < 1000; i++)
36 			barrier();
37 
38 		err = gettimeofday(&now, NULL);
39 		if (err)
40 			return err;
41 
42 		timersub(&now, &start, &diff);
43 		if (timercmp(&diff, &maxtime, > /* For checkpatch */))
44 			break;
45 	}
46 
47 	ts.tv_nsec = 50 * 1000 * 1000;
48 	ts.tv_sec = 0;
49 
50 	/* Sleep for 50ms */
51 	err = nanosleep(&ts, NULL);
52 	if (err == EINTR)
53 		err = 0;
54 
55 	return err;
56 }
57 
58 struct switch_tracking {
59 	struct evsel *switch_evsel;
60 	struct evsel *cycles_evsel;
61 	pid_t *tids;
62 	int nr_tids;
63 	int comm_seen[4];
64 	int cycles_before_comm_1;
65 	int cycles_between_comm_2_and_comm_3;
66 	int cycles_after_comm_4;
67 };
68 
69 static int check_comm(struct switch_tracking *switch_tracking,
70 		      union perf_event *event, const char *comm, int nr)
71 {
72 	if (event->header.type == PERF_RECORD_COMM &&
73 	    (pid_t)event->comm.pid == getpid() &&
74 	    (pid_t)event->comm.tid == getpid() &&
75 	    strcmp(event->comm.comm, comm) == 0) {
76 		if (switch_tracking->comm_seen[nr]) {
77 			pr_debug("Duplicate comm event\n");
78 			return -1;
79 		}
80 		switch_tracking->comm_seen[nr] = 1;
81 		pr_debug3("comm event: %s nr: %d\n", event->comm.comm, nr);
82 		return 1;
83 	}
84 	return 0;
85 }
86 
87 static int check_cpu(struct switch_tracking *switch_tracking, int cpu)
88 {
89 	int i, nr = cpu + 1;
90 
91 	if (cpu < 0)
92 		return -1;
93 
94 	if (!switch_tracking->tids) {
95 		switch_tracking->tids = calloc(nr, sizeof(pid_t));
96 		if (!switch_tracking->tids)
97 			return -1;
98 		for (i = 0; i < nr; i++)
99 			switch_tracking->tids[i] = -1;
100 		switch_tracking->nr_tids = nr;
101 		return 0;
102 	}
103 
104 	if (cpu >= switch_tracking->nr_tids) {
105 		void *addr;
106 
107 		addr = realloc(switch_tracking->tids, nr * sizeof(pid_t));
108 		if (!addr)
109 			return -1;
110 		switch_tracking->tids = addr;
111 		for (i = switch_tracking->nr_tids; i < nr; i++)
112 			switch_tracking->tids[i] = -1;
113 		switch_tracking->nr_tids = nr;
114 		return 0;
115 	}
116 
117 	return 0;
118 }
119 
120 static int process_sample_event(struct evlist *evlist,
121 				union perf_event *event,
122 				struct switch_tracking *switch_tracking)
123 {
124 	struct perf_sample sample;
125 	struct evsel *evsel;
126 	pid_t next_tid, prev_tid;
127 	int cpu, err;
128 
129 	if (perf_evlist__parse_sample(evlist, event, &sample)) {
130 		pr_debug("perf_evlist__parse_sample failed\n");
131 		return -1;
132 	}
133 
134 	evsel = perf_evlist__id2evsel(evlist, sample.id);
135 	if (evsel == switch_tracking->switch_evsel) {
136 		next_tid = perf_evsel__intval(evsel, &sample, "next_pid");
137 		prev_tid = perf_evsel__intval(evsel, &sample, "prev_pid");
138 		cpu = sample.cpu;
139 		pr_debug3("sched_switch: cpu: %d prev_tid %d next_tid %d\n",
140 			  cpu, prev_tid, next_tid);
141 		err = check_cpu(switch_tracking, cpu);
142 		if (err)
143 			return err;
144 		/*
145 		 * Check for no missing sched_switch events i.e. that the
146 		 * evsel->system_wide flag has worked.
147 		 */
148 		if (switch_tracking->tids[cpu] != -1 &&
149 		    switch_tracking->tids[cpu] != prev_tid) {
150 			pr_debug("Missing sched_switch events\n");
151 			return -1;
152 		}
153 		switch_tracking->tids[cpu] = next_tid;
154 	}
155 
156 	if (evsel == switch_tracking->cycles_evsel) {
157 		pr_debug3("cycles event\n");
158 		if (!switch_tracking->comm_seen[0])
159 			switch_tracking->cycles_before_comm_1 = 1;
160 		if (switch_tracking->comm_seen[1] &&
161 		    !switch_tracking->comm_seen[2])
162 			switch_tracking->cycles_between_comm_2_and_comm_3 = 1;
163 		if (switch_tracking->comm_seen[3])
164 			switch_tracking->cycles_after_comm_4 = 1;
165 	}
166 
167 	return 0;
168 }
169 
170 static int process_event(struct evlist *evlist, union perf_event *event,
171 			 struct switch_tracking *switch_tracking)
172 {
173 	if (event->header.type == PERF_RECORD_SAMPLE)
174 		return process_sample_event(evlist, event, switch_tracking);
175 
176 	if (event->header.type == PERF_RECORD_COMM) {
177 		int err, done = 0;
178 
179 		err = check_comm(switch_tracking, event, "Test COMM 1", 0);
180 		if (err < 0)
181 			return -1;
182 		done += err;
183 		err = check_comm(switch_tracking, event, "Test COMM 2", 1);
184 		if (err < 0)
185 			return -1;
186 		done += err;
187 		err = check_comm(switch_tracking, event, "Test COMM 3", 2);
188 		if (err < 0)
189 			return -1;
190 		done += err;
191 		err = check_comm(switch_tracking, event, "Test COMM 4", 3);
192 		if (err < 0)
193 			return -1;
194 		done += err;
195 		if (done != 1) {
196 			pr_debug("Unexpected comm event\n");
197 			return -1;
198 		}
199 	}
200 
201 	return 0;
202 }
203 
204 struct event_node {
205 	struct list_head list;
206 	union perf_event *event;
207 	u64 event_time;
208 };
209 
210 static int add_event(struct evlist *evlist, struct list_head *events,
211 		     union perf_event *event)
212 {
213 	struct perf_sample sample;
214 	struct event_node *node;
215 
216 	node = malloc(sizeof(struct event_node));
217 	if (!node) {
218 		pr_debug("malloc failed\n");
219 		return -1;
220 	}
221 	node->event = event;
222 	list_add(&node->list, events);
223 
224 	if (perf_evlist__parse_sample(evlist, event, &sample)) {
225 		pr_debug("perf_evlist__parse_sample failed\n");
226 		return -1;
227 	}
228 
229 	if (!sample.time) {
230 		pr_debug("event with no time\n");
231 		return -1;
232 	}
233 
234 	node->event_time = sample.time;
235 
236 	return 0;
237 }
238 
239 static void free_event_nodes(struct list_head *events)
240 {
241 	struct event_node *node;
242 
243 	while (!list_empty(events)) {
244 		node = list_entry(events->next, struct event_node, list);
245 		list_del_init(&node->list);
246 		free(node);
247 	}
248 }
249 
250 static int compar(const void *a, const void *b)
251 {
252 	const struct event_node *nodea = a;
253 	const struct event_node *nodeb = b;
254 	s64 cmp = nodea->event_time - nodeb->event_time;
255 
256 	return cmp;
257 }
258 
259 static int process_events(struct evlist *evlist,
260 			  struct switch_tracking *switch_tracking)
261 {
262 	union perf_event *event;
263 	unsigned pos, cnt = 0;
264 	LIST_HEAD(events);
265 	struct event_node *events_array, *node;
266 	struct perf_mmap *md;
267 	int i, ret;
268 
269 	for (i = 0; i < evlist->nr_mmaps; i++) {
270 		md = &evlist->mmap[i];
271 		if (perf_mmap__read_init(md) < 0)
272 			continue;
273 
274 		while ((event = perf_mmap__read_event(md)) != NULL) {
275 			cnt += 1;
276 			ret = add_event(evlist, &events, event);
277 			 perf_mmap__consume(md);
278 			if (ret < 0)
279 				goto out_free_nodes;
280 		}
281 		perf_mmap__read_done(md);
282 	}
283 
284 	events_array = calloc(cnt, sizeof(struct event_node));
285 	if (!events_array) {
286 		pr_debug("calloc failed\n");
287 		ret = -1;
288 		goto out_free_nodes;
289 	}
290 
291 	pos = 0;
292 	list_for_each_entry(node, &events, list)
293 		events_array[pos++] = *node;
294 
295 	qsort(events_array, cnt, sizeof(struct event_node), compar);
296 
297 	for (pos = 0; pos < cnt; pos++) {
298 		ret = process_event(evlist, events_array[pos].event,
299 				    switch_tracking);
300 		if (ret < 0)
301 			goto out_free;
302 	}
303 
304 	ret = 0;
305 out_free:
306 	pr_debug("%u events recorded\n", cnt);
307 	free(events_array);
308 out_free_nodes:
309 	free_event_nodes(&events);
310 	return ret;
311 }
312 
313 /**
314  * test__switch_tracking - test using sched_switch and tracking events.
315  *
316  * This function implements a test that checks that sched_switch events and
317  * tracking events can be recorded for a workload (current process) using the
318  * evsel->system_wide and evsel->tracking flags (respectively) with other events
319  * sometimes enabled or disabled.
320  */
321 int test__switch_tracking(struct test *test __maybe_unused, int subtest __maybe_unused)
322 {
323 	const char *sched_switch = "sched:sched_switch";
324 	struct switch_tracking switch_tracking = { .tids = NULL, };
325 	struct record_opts opts = {
326 		.mmap_pages	     = UINT_MAX,
327 		.user_freq	     = UINT_MAX,
328 		.user_interval	     = ULLONG_MAX,
329 		.freq		     = 4000,
330 		.target		     = {
331 			.uses_mmap   = true,
332 		},
333 	};
334 	struct perf_thread_map *threads = NULL;
335 	struct perf_cpu_map *cpus = NULL;
336 	struct evlist *evlist = NULL;
337 	struct evsel *evsel, *cpu_clocks_evsel, *cycles_evsel;
338 	struct evsel *switch_evsel, *tracking_evsel;
339 	const char *comm;
340 	int err = -1;
341 
342 	threads = thread_map__new(-1, getpid(), UINT_MAX);
343 	if (!threads) {
344 		pr_debug("thread_map__new failed!\n");
345 		goto out_err;
346 	}
347 
348 	cpus = perf_cpu_map__new(NULL);
349 	if (!cpus) {
350 		pr_debug("perf_cpu_map__new failed!\n");
351 		goto out_err;
352 	}
353 
354 	evlist = evlist__new();
355 	if (!evlist) {
356 		pr_debug("evlist__new failed!\n");
357 		goto out_err;
358 	}
359 
360 	perf_evlist__set_maps(&evlist->core, cpus, threads);
361 
362 	/* First event */
363 	err = parse_events(evlist, "cpu-clock:u", NULL);
364 	if (err) {
365 		pr_debug("Failed to parse event dummy:u\n");
366 		goto out_err;
367 	}
368 
369 	cpu_clocks_evsel = perf_evlist__last(evlist);
370 
371 	/* Second event */
372 	err = parse_events(evlist, "cycles:u", NULL);
373 	if (err) {
374 		pr_debug("Failed to parse event cycles:u\n");
375 		goto out_err;
376 	}
377 
378 	cycles_evsel = perf_evlist__last(evlist);
379 
380 	/* Third event */
381 	if (!perf_evlist__can_select_event(evlist, sched_switch)) {
382 		pr_debug("No sched_switch\n");
383 		err = 0;
384 		goto out;
385 	}
386 
387 	err = parse_events(evlist, sched_switch, NULL);
388 	if (err) {
389 		pr_debug("Failed to parse event %s\n", sched_switch);
390 		goto out_err;
391 	}
392 
393 	switch_evsel = perf_evlist__last(evlist);
394 
395 	perf_evsel__set_sample_bit(switch_evsel, CPU);
396 	perf_evsel__set_sample_bit(switch_evsel, TIME);
397 
398 	switch_evsel->system_wide = true;
399 	switch_evsel->no_aux_samples = true;
400 	switch_evsel->immediate = true;
401 
402 	/* Test moving an event to the front */
403 	if (cycles_evsel == perf_evlist__first(evlist)) {
404 		pr_debug("cycles event already at front");
405 		goto out_err;
406 	}
407 	perf_evlist__to_front(evlist, cycles_evsel);
408 	if (cycles_evsel != perf_evlist__first(evlist)) {
409 		pr_debug("Failed to move cycles event to front");
410 		goto out_err;
411 	}
412 
413 	perf_evsel__set_sample_bit(cycles_evsel, CPU);
414 	perf_evsel__set_sample_bit(cycles_evsel, TIME);
415 
416 	/* Fourth event */
417 	err = parse_events(evlist, "dummy:u", NULL);
418 	if (err) {
419 		pr_debug("Failed to parse event dummy:u\n");
420 		goto out_err;
421 	}
422 
423 	tracking_evsel = perf_evlist__last(evlist);
424 
425 	perf_evlist__set_tracking_event(evlist, tracking_evsel);
426 
427 	tracking_evsel->core.attr.freq = 0;
428 	tracking_evsel->core.attr.sample_period = 1;
429 
430 	perf_evsel__set_sample_bit(tracking_evsel, TIME);
431 
432 	/* Config events */
433 	perf_evlist__config(evlist, &opts, NULL);
434 
435 	/* Check moved event is still at the front */
436 	if (cycles_evsel != perf_evlist__first(evlist)) {
437 		pr_debug("Front event no longer at front");
438 		goto out_err;
439 	}
440 
441 	/* Check tracking event is tracking */
442 	if (!tracking_evsel->core.attr.mmap || !tracking_evsel->core.attr.comm) {
443 		pr_debug("Tracking event not tracking\n");
444 		goto out_err;
445 	}
446 
447 	/* Check non-tracking events are not tracking */
448 	evlist__for_each_entry(evlist, evsel) {
449 		if (evsel != tracking_evsel) {
450 			if (evsel->core.attr.mmap || evsel->core.attr.comm) {
451 				pr_debug("Non-tracking event is tracking\n");
452 				goto out_err;
453 			}
454 		}
455 	}
456 
457 	if (evlist__open(evlist) < 0) {
458 		pr_debug("Not supported\n");
459 		err = 0;
460 		goto out;
461 	}
462 
463 	err = perf_evlist__mmap(evlist, UINT_MAX);
464 	if (err) {
465 		pr_debug("perf_evlist__mmap failed!\n");
466 		goto out_err;
467 	}
468 
469 	evlist__enable(evlist);
470 
471 	err = evsel__disable(cpu_clocks_evsel);
472 	if (err) {
473 		pr_debug("perf_evlist__disable_event failed!\n");
474 		goto out_err;
475 	}
476 
477 	err = spin_sleep();
478 	if (err) {
479 		pr_debug("spin_sleep failed!\n");
480 		goto out_err;
481 	}
482 
483 	comm = "Test COMM 1";
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 = evsel__disable(cycles_evsel);
491 	if (err) {
492 		pr_debug("perf_evlist__disable_event failed!\n");
493 		goto out_err;
494 	}
495 
496 	comm = "Test COMM 2";
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 = spin_sleep();
504 	if (err) {
505 		pr_debug("spin_sleep failed!\n");
506 		goto out_err;
507 	}
508 
509 	comm = "Test COMM 3";
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 = evsel__enable(cycles_evsel);
517 	if (err) {
518 		pr_debug("perf_evlist__disable_event failed!\n");
519 		goto out_err;
520 	}
521 
522 	comm = "Test COMM 4";
523 	err = prctl(PR_SET_NAME, (unsigned long)comm, 0, 0, 0);
524 	if (err) {
525 		pr_debug("PR_SET_NAME failed!\n");
526 		goto out_err;
527 	}
528 
529 	err = spin_sleep();
530 	if (err) {
531 		pr_debug("spin_sleep failed!\n");
532 		goto out_err;
533 	}
534 
535 	evlist__disable(evlist);
536 
537 	switch_tracking.switch_evsel = switch_evsel;
538 	switch_tracking.cycles_evsel = cycles_evsel;
539 
540 	err = process_events(evlist, &switch_tracking);
541 
542 	zfree(&switch_tracking.tids);
543 
544 	if (err)
545 		goto out_err;
546 
547 	/* Check all 4 comm events were seen i.e. that evsel->tracking works */
548 	if (!switch_tracking.comm_seen[0] || !switch_tracking.comm_seen[1] ||
549 	    !switch_tracking.comm_seen[2] || !switch_tracking.comm_seen[3]) {
550 		pr_debug("Missing comm events\n");
551 		goto out_err;
552 	}
553 
554 	/* Check cycles event got enabled */
555 	if (!switch_tracking.cycles_before_comm_1) {
556 		pr_debug("Missing cycles events\n");
557 		goto out_err;
558 	}
559 
560 	/* Check cycles event got disabled */
561 	if (switch_tracking.cycles_between_comm_2_and_comm_3) {
562 		pr_debug("cycles events even though event was disabled\n");
563 		goto out_err;
564 	}
565 
566 	/* Check cycles event got enabled again */
567 	if (!switch_tracking.cycles_after_comm_4) {
568 		pr_debug("Missing cycles events\n");
569 		goto out_err;
570 	}
571 out:
572 	if (evlist) {
573 		evlist__disable(evlist);
574 		evlist__delete(evlist);
575 	} else {
576 		perf_cpu_map__put(cpus);
577 		perf_thread_map__put(threads);
578 	}
579 
580 	return err;
581 
582 out_err:
583 	err = -1;
584 	goto out;
585 }
586