summaryrefslogtreecommitdiffstats
path: root/tools/perf/tests/switch-tracking.c
blob: a02af503100c9c51c1f961c9e089546ccdcfd000 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
#include <sys/time.h>
#include <sys/prctl.h>
#include <time.h>
#include <stdlib.h>

#include "parse-events.h"
#include "evlist.h"
#include "evsel.h"
#include "thread_map.h"
#include "cpumap.h"
#include "tests.h"

static int spin_sleep(void)
{
	struct timeval start, now, diff, maxtime;
	struct timespec ts;
	int err, i;

	maxtime.tv_sec = 0;
	maxtime.tv_usec = 50000;

	err = gettimeofday(&start, NULL);
	if (err)
		return err;

	/* Spin for 50ms */
	while (1) {
		for (i = 0; i < 1000; i++)
			barrier();

		err = gettimeofday(&now, NULL);
		if (err)
			return err;

		timersub(&now, &start, &diff);
		if (timercmp(&diff, &maxtime, > /* For checkpatch */))
			break;
	}

	ts.tv_nsec = 50 * 1000 * 1000;
	ts.tv_sec = 0;

	/* Sleep for 50ms */
	err = nanosleep(&ts, NULL);
	if (err == EINTR)
		err = 0;

	return err;
}

struct switch_tracking {
	struct perf_evsel *switch_evsel;
	struct perf_evsel *cycles_evsel;
	pid_t *tids;
	int nr_tids;
	int comm_seen[4];
	int cycles_before_comm_1;
	int cycles_between_comm_2_and_comm_3;
	int cycles_after_comm_4;
};

static int check_comm(struct switch_tracking *switch_tracking,
		      union perf_event *event, const char *comm, int nr)
{
	if (event->header.type == PERF_RECORD_COMM &&
	    (pid_t)event->comm.pid == getpid() &&
	    (pid_t)event->comm.tid == getpid() &&
	    strcmp(event->comm.comm, comm) == 0) {
		if (switch_tracking->comm_seen[nr]) {
			pr_debug("Duplicate comm event\n");
			return -1;
		}
		switch_tracking->comm_seen[nr] = 1;
		pr_debug3("comm event: %s nr: %d\n", event->comm.comm, nr);
		return 1;
	}
	return 0;
}

static int check_cpu(struct switch_tracking *switch_tracking, int cpu)
{
	int i, nr = cpu + 1;

	if (cpu < 0)
		return -1;

	if (!switch_tracking->tids) {
		switch_tracking->tids = calloc(nr, sizeof(pid_t));
		if (!switch_tracking->tids)
			return -1;
		for (i = 0; i < nr; i++)
			switch_tracking->tids[i] = -1;
		switch_tracking->nr_tids = nr;
		return 0;
	}

	if (cpu >= switch_tracking->nr_tids) {
		void *addr;

		addr = realloc(switch_tracking->tids, nr * sizeof(pid_t));
		if (!addr)
			return -1;
		switch_tracking->tids = addr;
		for (i = switch_tracking->nr_tids; i < nr; i++)
			switch_tracking->tids[i] = -1;
		switch_tracking->nr_tids = nr;
		return 0;
	}

	return 0;
}

static int process_sample_event(struct perf_evlist *evlist,
				union perf_event *event,
				struct switch_tracking *switch_tracking)
{
	struct perf_sample sample;
	struct perf_evsel *evsel;
	pid_t next_tid, prev_tid;
	int cpu, err;

	if (perf_evlist__parse_sample(evlist, event, &sample)) {
		pr_debug("perf_evlist__parse_sample failed\n");
		return -1;
	}

	evsel = perf_evlist__id2evsel(evlist, sample.id);
	if (evsel == switch_tracking->switch_evsel) {
		next_tid = perf_evsel__intval(evsel, &sample, "next_pid");
		prev_tid = perf_evsel__intval(evsel, &sample, "prev_pid");
		cpu = sample.cpu;
		pr_debug3("sched_switch: cpu: %d prev_tid %d next_tid %d\n",
			  cpu, prev_tid, next_tid);
		err = check_cpu(switch_tracking, cpu);
		if (err)
			return err;
		/*
		 * Check for no missing sched_switch events i.e. that the
		 * evsel->system_wide flag has worked.
		 */
		if (switch_tracking->tids[cpu] != -1 &&
		    switch_tracking->tids[cpu] != prev_tid) {
			pr_debug("Missing sched_switch events\n");
			return -1;
		}
		switch_tracking->tids[cpu] = next_tid;
	}

	if (evsel == switch_tracking->cycles_evsel) {
		pr_debug3("cycles event\n");
		if (!switch_tracking->comm_seen[0])
			switch_tracking->cycles_before_comm_1 = 1;
		if (switch_tracking->comm_seen[1] &&
		    !switch_tracking->comm_seen[2])
			switch_tracking->cycles_between_comm_2_and_comm_3 = 1;
		if (switch_tracking->comm_seen[3])
			switch_tracking->cycles_after_comm_4 = 1;
	}

	return 0;
}

static int process_event(struct perf_evlist *evlist, union perf_event *event,
			 struct switch_tracking *switch_tracking)
{
	if (event->header.type == PERF_RECORD_SAMPLE)
		return process_sample_event(evlist, event, switch_tracking);

	if (event->header.type == PERF_RECORD_COMM) {
		int err, done = 0;

		err = check_comm(switch_tracking, event, "Test COMM 1", 0);
		if (err < 0)
			return -1;
		done += err;
		err = check_comm(switch_tracking, event, "Test COMM 2", 1);
		if (err < 0)
			return -1;
		done += err;
		err = check_comm(switch_tracking, event, "Test COMM 3", 2);
		if (err < 0)
			return -1;
		done += err;
		err = check_comm(switch_tracking, event, "Test COMM 4", 3);
		if (err < 0)
			return -1;
		done += err;
		if (done != 1) {
			pr_debug("Unexpected comm event\n");
			return -1;
		}
	}

	return 0;
}

struct event_node {
	struct list_head list;
	union perf_event *event;
	u64 event_time;
};

static int add_event(struct perf_evlist *evlist, struct list_head *events,
		     union perf_event *event)
{
	struct perf_sample sample;
	struct event_node *node;

	node = malloc(sizeof(struct event_node));
	if (!node) {
		pr_debug("malloc failed\n");
		return -1;
	}
	node->event = event;
	list_add(&node->list, events);

	if (perf_evlist__parse_sample(evlist, event, &sample)) {
		pr_debug("perf_evlist__parse_sample failed\n");
		return -1;
	}

	if (!sample.time) {
		pr_debug("event with no time\n");
		return -1;
	}

	node->event_time = sample.time;

	return 0;
}

static void free_event_nodes(struct list_head *events)
{
	struct event_node *node;

	while (!list_empty(events)) {
		node = list_entry(events->next, struct event_node, list);
		list_del(&node->list);
		free(node);
	}
}

static int compar(const void *a, const void *b)
{
	const struct event_node *nodea = a;
	const struct event_node *nodeb = b;
	s64 cmp = nodea->event_time - nodeb->event_time;

	return cmp;
}

static int process_events(struct perf_evlist *evlist,
			  struct switch_tracking *switch_tracking)
{
	union perf_event *event;
	unsigned pos, cnt = 0;
	LIST_HEAD(events);
	struct event_node *events_array, *node;
	int i, ret;

	for (i = 0; i < evlist->nr_mmaps; i++) {
		while ((event = perf_evlist__mmap_read(evlist, i)) != NULL) {
			cnt += 1;
			ret = add_event(evlist, &events, event);
			perf_evlist__mmap_consume(evlist, i);
			if (ret < 0)
				goto out_free_nodes;
		}
	}

	events_array = calloc(cnt, sizeof(struct event_node));
	if (!events_array) {
		pr_debug("calloc failed\n");
		ret = -1;
		goto out_free_nodes;
	}

	pos = 0;
	list_for_each_entry(node, &events, list)
		events_array[pos++] = *node;

	qsort(events_array, cnt, sizeof(struct event_node), compar);

	for (pos = 0; pos < cnt; pos++) {
		ret = process_event(evlist, events_array[pos].event,
				    switch_tracking);
		if (ret < 0)
			goto out_free;
	}

	ret = 0;
out_free:
	pr_debug("%u events recorded\n", cnt);
	free(events_array);
out_free_nodes:
	free_event_nodes(&events);
	return ret;
}

/**
 * test__switch_tracking - test using sched_switch and tracking events.
 *
 * This function implements a test that checks that sched_switch events and
 * tracking events can be recorded for a workload (current process) using the
 * evsel->system_wide and evsel->tracking flags (respectively) with other events
 * sometimes enabled or disabled.
 */
int test__switch_tracking(void)
{
	const char *sched_switch = "sched:sched_switch";
	struct switch_tracking switch_tracking = { .tids = NULL, };
	struct record_opts opts = {
		.mmap_pages	     = UINT_MAX,
		.user_freq	     = UINT_MAX,
		.user_interval	     = ULLONG_MAX,
		.freq		     = 4000,
		.target		     = {
			.uses_mmap   = true,
		},
	};
	struct thread_map *threads = NULL;
	struct cpu_map *cpus = NULL;
	struct perf_evlist *evlist = NULL;
	struct perf_evsel *evsel, *cpu_clocks_evsel, *cycles_evsel;
	struct perf_evsel *switch_evsel, *tracking_evsel;
	const char *comm;
	int err = -1;

	threads = thread_map__new(-1, getpid(), UINT_MAX);
	if (!threads) {
		pr_debug("thread_map__new failed!\n");
		goto out_err;
	}

	cpus = cpu_map__new(NULL);
	if (!cpus) {
		pr_debug("cpu_map__new failed!\n");
		goto out_err;
	}

	evlist = perf_evlist__new();
	if (!evlist) {
		pr_debug("perf_evlist__new failed!\n");
		goto out_err;
	}

	perf_evlist__set_maps(evlist, cpus, threads);

	/* First event */
	err = parse_events(evlist, "cpu-clock:u", NULL);
	if (err) {
		pr_debug("Failed to parse event dummy:u\n");
		goto out_err;
	}

	cpu_clocks_evsel = perf_evlist__last(evlist);

	/* Second event */
	err = parse_events(evlist, "cycles:u", NULL);
	if (err) {
		pr_debug("Failed to parse event cycles:u\n");
		goto out_err;
	}

	cycles_evsel = perf_evlist__last(evlist);

	/* Third event */
	if (!perf_evlist__can_select_event(evlist, sched_switch)) {
		pr_debug("No sched_switch\n");
		err = 0;
		goto out;
	}

	err = parse_events(evlist, sched_switch, NULL);
	if (err) {
		pr_debug("Failed to parse event %s\n", sched_switch);
		goto out_err;
	}

	switch_evsel = perf_evlist__last(evlist);

	perf_evsel__set_sample_bit(switch_evsel, CPU);
	perf_evsel__set_sample_bit(switch_evsel, TIME);

	switch_evsel->system_wide = true;
	switch_evsel->no_aux_samples = true;
	switch_evsel->immediate = true;

	/* Test moving an event to the front */
	if (cycles_evsel == perf_evlist__first(evlist)) {
		pr_debug("cycles event already at front");
		goto out_err;
	}
	perf_evlist__to_front(evlist, cycles_evsel);
	if (cycles_evsel != perf_evlist__first(evlist)) {
		pr_debug("Failed to move cycles event to front");
		goto out_err;
	}

	perf_evsel__set_sample_bit(cycles_evsel, CPU);
	perf_evsel__set_sample_bit(cycles_evsel, TIME);

	/* Fourth event */
	err = parse_events(evlist, "dummy:u", NULL);
	if (err) {
		pr_debug("Failed to parse event dummy:u\n");
		goto out_err;
	}

	tracking_evsel = perf_evlist__last(evlist);

	perf_evlist__set_tracking_event(evlist, tracking_evsel);

	tracking_evsel->attr.freq = 0;
	tracking_evsel->attr.sample_period = 1;

	perf_evsel__set_sample_bit(tracking_evsel, TIME);

	/* Config events */
	perf_evlist__config(evlist, &opts);

	/* Check moved event is still at the front */
	if (cycles_evsel != perf_evlist__first(evlist)) {
		pr_debug("Front event no longer at front");
		goto out_err;
	}

	/* Check tracking event is tracking */
	if (!tracking_evsel->attr.mmap || !tracking_evsel->attr.comm) {
		pr_debug("Tracking event not tracking\n");
		goto out_err;
	}

	/* Check non-tracking events are not tracking */
	evlist__for_each(evlist, evsel) {
		if (evsel != tracking_evsel) {
			if (evsel->attr.mmap || evsel->attr.comm) {
				pr_debug("Non-tracking event is tracking\n");
				goto out_err;
			}
		}
	}

	if (perf_evlist__open(evlist) < 0) {
		pr_debug("Not supported\n");
		err = 0;
		goto out;
	}

	err = perf_evlist__mmap(evlist, UINT_MAX, false);
	if (err) {
		pr_debug("perf_evlist__mmap failed!\n");
		goto out_err;
	}

	perf_evlist__enable(evlist);

	err = perf_evlist__disable_event(evlist, cpu_clocks_evsel);
	if (err) {
		pr_debug("perf_evlist__disable_event failed!\n");
		goto out_err;
	}

	err = spin_sleep();
	if (err) {
		pr_debug("spin_sleep failed!\n");
		goto out_err;
	}

	comm = "Test COMM 1";
	err = prctl(PR_SET_NAME, (unsigned long)comm, 0, 0, 0);
	if (err) {
		pr_debug("PR_SET_NAME failed!\n");
		goto out_err;
	}

	err = perf_evlist__disable_event(evlist, cycles_evsel);
	if (err) {
		pr_debug("perf_evlist__disable_event failed!\n");
		goto out_err;
	}

	comm = "Test COMM 2";
	err = prctl(PR_SET_NAME, (unsigned long)comm, 0, 0, 0);
	if (err) {
		pr_debug("PR_SET_NAME failed!\n");
		goto out_err;
	}

	err = spin_sleep();
	if (err) {
		pr_debug("spin_sleep failed!\n");
		goto out_err;
	}

	comm = "Test COMM 3";
	err = prctl(PR_SET_NAME, (unsigned long)comm, 0, 0, 0);
	if (err) {
		pr_debug("PR_SET_NAME failed!\n");
		goto out_err;
	}

	err = perf_evlist__enable_event(evlist, cycles_evsel);
	if (err) {
		pr_debug("perf_evlist__disable_event failed!\n");
		goto out_err;
	}

	comm = "Test COMM 4";
	err = prctl(PR_SET_NAME, (unsigned long)comm, 0, 0, 0);
	if (err) {
		pr_debug("PR_SET_NAME failed!\n");
		goto out_err;
	}

	err = spin_sleep();
	if (err) {
		pr_debug("spin_sleep failed!\n");
		goto out_err;
	}

	perf_evlist__disable(evlist);

	switch_tracking.switch_evsel = switch_evsel;
	switch_tracking.cycles_evsel = cycles_evsel;

	err = process_events(evlist, &switch_tracking);

	zfree(&switch_tracking.tids);

	if (err)
		goto out_err;

	/* Check all 4 comm events were seen i.e. that evsel->tracking works */
	if (!switch_tracking.comm_seen[0] || !switch_tracking.comm_seen[1] ||
	    !switch_tracking.comm_seen[2] || !switch_tracking.comm_seen[3]) {
		pr_debug("Missing comm events\n");
		goto out_err;
	}

	/* Check cycles event got enabled */
	if (!switch_tracking.cycles_before_comm_1) {
		pr_debug("Missing cycles events\n");
		goto out_err;
	}

	/* Check cycles event got disabled */
	if (switch_tracking.cycles_between_comm_2_and_comm_3) {
		pr_debug("cycles events even though event was disabled\n");
		goto out_err;
	}

	/* Check cycles event got enabled again */
	if (!switch_tracking.cycles_after_comm_4) {
		pr_debug("Missing cycles events\n");
		goto out_err;
	}
out:
	if (evlist) {
		perf_evlist__disable(evlist);
		perf_evlist__delete(evlist);
	} else {
		cpu_map__put(cpus);
		thread_map__put(threads);
	}

	return err;

out_err:
	err = -1;
	goto out;
}