1 // SPDX-License-Identifier: GPL-2.0
2 #include <sys/time.h>
3 #include <sys/prctl.h>
4 #include <errno.h>
5 #include <limits.h>
6 #include <time.h>
7 #include <stdlib.h>
8 #include <linux/zalloc.h>
9 #include <linux/err.h>
10 #include <perf/cpumap.h>
11 #include <perf/evlist.h>
12 #include <perf/mmap.h>
13
14 #include "debug.h"
15 #include "parse-events.h"
16 #include "evlist.h"
17 #include "evsel.h"
18 #include "thread_map.h"
19 #include "record.h"
20 #include "tests.h"
21 #include "util/mmap.h"
22 #include "util/sample.h"
23 #include "pmus.h"
24
25 static int spin_sleep(void)
26 {
27 struct timeval start, now, diff, maxtime;
28 struct timespec ts;
29 int err, i;
30
31 maxtime.tv_sec = 0;
32 maxtime.tv_usec = 50000;
33
34 err = gettimeofday(&start, NULL);
35 if (err)
36 return err;
37
38 /* Spin for 50ms */
39 while (1) {
40 for (i = 0; i < 1000; i++)
41 barrier();
42
43 err = gettimeofday(&now, NULL);
44 if (err)
45 return err;
46
47 timersub(&now, &start, &diff);
48 if (timercmp(&diff, &maxtime, > /* For checkpatch */))
49 break;
50 }
51
52 ts.tv_nsec = 50 * 1000 * 1000;
53 ts.tv_sec = 0;
54
55 /* Sleep for 50ms */
56 err = nanosleep(&ts, NULL);
57 if (err == EINTR)
58 err = 0;
59
60 return err;
61 }
62
63 struct switch_tracking {
64 struct evsel *switch_evsel;
65 struct evsel *cycles_evsel;
66 pid_t *tids;
67 int nr_tids;
68 int comm_seen[4];
69 int cycles_before_comm_1;
70 int cycles_between_comm_2_and_comm_3;
71 int cycles_after_comm_4;
72 };
73
74 static int check_comm(struct switch_tracking *switch_tracking,
75 union perf_event *event, const char *comm, int nr)
76 {
77 if (event->header.type == PERF_RECORD_COMM &&
78 (pid_t)event->comm.pid == getpid() &&
79 (pid_t)event->comm.tid == getpid() &&
80 strcmp(event->comm.comm, comm) == 0) {
81 if (switch_tracking->comm_seen[nr]) {
82 pr_debug("Duplicate comm event\n");
83 return -1;
84 }
85 switch_tracking->comm_seen[nr] = 1;
86 pr_debug3("comm event: %s nr: %d\n", event->comm.comm, nr);
87 return 1;
88 }
89 return 0;
90 }
91
92 static int check_cpu(struct switch_tracking *switch_tracking, int cpu)
93 {
94 int i, nr = cpu + 1;
95
96 if (cpu < 0)
97 return -1;
98
99 if (!switch_tracking->tids) {
100 switch_tracking->tids = calloc(nr, sizeof(pid_t));
101 if (!switch_tracking->tids)
102 return -1;
103 for (i = 0; i < nr; i++)
104 switch_tracking->tids[i] = -1;
105 switch_tracking->nr_tids = nr;
106 return 0;
107 }
108
109 if (cpu >= switch_tracking->nr_tids) {
110 void *addr;
111
112 addr = realloc(switch_tracking->tids, nr * sizeof(pid_t));
113 if (!addr)
114 return -1;
115 switch_tracking->tids = addr;
116 for (i = switch_tracking->nr_tids; i < nr; i++)
117 switch_tracking->tids[i] = -1;
118 switch_tracking->nr_tids = nr;
119 return 0;
120 }
121
122 return 0;
123 }
124
125 static int process_sample_event(struct evlist *evlist,
126 union perf_event *event,
127 struct switch_tracking *switch_tracking)
128 {
129 struct perf_sample sample;
130 struct evsel *evsel;
131 pid_t next_tid, prev_tid;
132 int cpu, err;
133
134 if (evlist__parse_sample(evlist, event, &sample)) {
135 pr_debug("evlist__parse_sample failed\n");
136 return -1;
137 }
138
139 evsel = evlist__id2evsel(evlist, sample.id);
140 if (evsel == switch_tracking->switch_evsel) {
141 next_tid = evsel__intval(evsel, &sample, "next_pid");
142 prev_tid = evsel__intval(evsel, &sample, "prev_pid");
143 cpu = sample.cpu;
144 pr_debug3("sched_switch: cpu: %d prev_tid %d next_tid %d\n",
145 cpu, prev_tid, next_tid);
146 err = check_cpu(switch_tracking, cpu);
147 if (err)
148 return err;
149 /*
150 * Check for no missing sched_switch events i.e. that the
151 * evsel->core.system_wide flag has worked.
152 */
153 if (switch_tracking->tids[cpu] != -1 &&
154 switch_tracking->tids[cpu] != prev_tid) {
155 pr_debug("Missing sched_switch events\n");
156 return -1;
157 }
158 switch_tracking->tids[cpu] = next_tid;
159 }
160
161 if (evsel == switch_tracking->cycles_evsel) {
162 pr_debug3("cycles event\n");
163 if (!switch_tracking->comm_seen[0])
164 switch_tracking->cycles_before_comm_1 = 1;
165 if (switch_tracking->comm_seen[1] &&
166 !switch_tracking->comm_seen[2])
167 switch_tracking->cycles_between_comm_2_and_comm_3 = 1;
168 if (switch_tracking->comm_seen[3])
169 switch_tracking->cycles_after_comm_4 = 1;
170 }
171
172 return 0;
173 }
174
175 static int process_event(struct evlist *evlist, union perf_event *event,
176 struct switch_tracking *switch_tracking)
177 {
178 if (event->header.type == PERF_RECORD_SAMPLE)
179 return process_sample_event(evlist, event, switch_tracking);
180
181 if (event->header.type == PERF_RECORD_COMM) {
182 int err, done = 0;
183
184 err = check_comm(switch_tracking, event, "Test COMM 1", 0);
185 if (err < 0)
186 return -1;
187 done += err;
188 err = check_comm(switch_tracking, event, "Test COMM 2", 1);
189 if (err < 0)
190 return -1;
191 done += err;
192 err = check_comm(switch_tracking, event, "Test COMM 3", 2);
193 if (err < 0)
194 return -1;
195 done += err;
196 err = check_comm(switch_tracking, event, "Test COMM 4", 3);
197 if (err < 0)
198 return -1;
199 done += err;
200 if (done != 1) {
201 pr_debug("Unexpected comm event\n");
202 return -1;
203 }
204 }
205
206 return 0;
207 }
208
209 struct event_node {
210 struct list_head list;
211 union perf_event *event;
212 u64 event_time;
213 };
214
215 static int add_event(struct evlist *evlist, struct list_head *events,
216 union perf_event *event)
217 {
218 struct perf_sample sample;
219 struct event_node *node;
220
221 node = malloc(sizeof(struct event_node));
222 if (!node) {
223 pr_debug("malloc failed\n");
224 return -1;
225 }
226 node->event = event;
227 list_add(&node->list, events);
228
229 if (evlist__parse_sample(evlist, event, &sample)) {
230 pr_debug("evlist__parse_sample failed\n");
231 return -1;
232 }
233
234 if (!sample.time) {
235 pr_debug("event with no time\n");
236 return -1;
237 }
238
239 node->event_time = sample.time;
240
241 return 0;
242 }
243
244 static void free_event_nodes(struct list_head *events)
245 {
246 struct event_node *node;
247
248 while (!list_empty(events)) {
249 node = list_entry(events->next, struct event_node, list);
250 list_del_init(&node->list);
251 free(node);
252 }
253 }
254
255 static int compar(const void *a, const void *b)
256 {
257 const struct event_node *nodea = a;
258 const struct event_node *nodeb = b;
259 s64 cmp = nodea->event_time - nodeb->event_time;
260
261 return cmp;
262 }
263
264 static int process_events(struct evlist *evlist,
265 struct switch_tracking *switch_tracking)
266 {
267 union perf_event *event;
268 unsigned pos, cnt = 0;
269 LIST_HEAD(events);
270 struct event_node *events_array, *node;
271 struct mmap *md;
272 int i, ret;
273
274 for (i = 0; i < evlist->core.nr_mmaps; i++) {
275 md = &evlist->mmap[i];
276 if (perf_mmap__read_init(&md->core) < 0)
277 continue;
278
279 while ((event = perf_mmap__read_event(&md->core)) != NULL) {
280 cnt += 1;
281 ret = add_event(evlist, &events, event);
282 perf_mmap__consume(&md->core);
283 if (ret < 0)
284 goto out_free_nodes;
285 }
286 perf_mmap__read_done(&md->core);
287 }
288
289 events_array = calloc(cnt, sizeof(struct event_node));
290 if (!events_array) {
291 pr_debug("calloc failed\n");
292 ret = -1;
293 goto out_free_nodes;
294 }
295
296 pos = 0;
297 list_for_each_entry(node, &events, list)
298 events_array[pos++] = *node;
299
300 qsort(events_array, cnt, sizeof(struct event_node), compar);
301
302 for (pos = 0; pos < cnt; pos++) {
303 ret = process_event(evlist, events_array[pos].event,
304 switch_tracking);
305 if (ret < 0)
306 goto out_free;
307 }
308
309 ret = 0;
310 out_free:
311 pr_debug("%u events recorded\n", cnt);
312 free(events_array);
313 out_free_nodes:
314 free_event_nodes(&events);
315 return ret;
316 }
317
318 /**
319 * test__switch_tracking - test using sched_switch and tracking events.
320 *
321 * This function implements a test that checks that sched_switch events and
322 * tracking events can be recorded for a workload (current process) using the
323 * evsel->core.system_wide and evsel->tracking flags (respectively) with other events
324 * sometimes enabled or disabled.
325 */
326 static int test__switch_tracking(struct test_suite *test __maybe_unused, int subtest __maybe_unused)
327 {
328 const char *sched_switch = "sched:sched_switch";
329 const char *cycles = "cycles:u";
330 struct switch_tracking switch_tracking = { .tids = NULL, };
331 struct record_opts opts = {
332 .mmap_pages = UINT_MAX,
333 .user_freq = UINT_MAX,
334 .user_interval = ULLONG_MAX,
335 .freq = 4000,
336 .target = {
337 .uses_mmap = true,
338 },
339 };
340 struct perf_thread_map *threads = NULL;
341 struct perf_cpu_map *cpus = NULL;
342 struct evlist *evlist = NULL;
343 struct evsel *evsel, *cpu_clocks_evsel, *cycles_evsel;
344 struct evsel *switch_evsel, *tracking_evsel;
345 const char *comm;
346 int err = -1;
347
348 threads = thread_map__new(-1, getpid(), UINT_MAX);
349 if (!threads) {
350 pr_debug("thread_map__new failed!\n");
351 goto out_err;
352 }
353
354 cpus = perf_cpu_map__new_online_cpus();
355 if (!cpus) {
356 pr_debug("perf_cpu_map__new failed!\n");
357 goto out_err;
358 }
359
360 evlist = evlist__new();
361 if (!evlist) {
362 pr_debug("evlist__new failed!\n");
363 goto out_err;
364 }
365
366 perf_evlist__set_maps(&evlist->core, cpus, threads);
367
368 /* First event */
369 err = parse_event(evlist, "cpu-clock:u");
370 if (err) {
371 pr_debug("Failed to parse event dummy:u\n");
372 goto out_err;
373 }
374
375 cpu_clocks_evsel = evlist__last(evlist);
376
377 /* Second event */
378 err = parse_event(evlist, cycles);
379 if (err) {
380 pr_debug("Failed to parse event %s\n", cycles);
381 goto out_err;
382 }
383
384 cycles_evsel = evlist__last(evlist);
385
386 /* Third event */
387 if (!evlist__can_select_event(evlist, sched_switch)) {
388 pr_debug("No sched_switch\n");
389 err = 0;
390 goto out;
391 }
392
393 switch_evsel = evlist__add_sched_switch(evlist, true);
394 if (IS_ERR(switch_evsel)) {
395 err = PTR_ERR(switch_evsel);
396 pr_debug("Failed to create event %s\n", sched_switch);
397 goto out_err;
398 }
399
400 switch_evsel->immediate = true;
401
402 /* Test moving an event to the front */
403 if (cycles_evsel == evlist__first(evlist)) {
404 pr_debug("cycles event already at front");
405 goto out_err;
406 }
407 evlist__to_front(evlist, cycles_evsel);
408 if (cycles_evsel != evlist__first(evlist)) {
409 pr_debug("Failed to move cycles event to front");
410 goto out_err;
411 }
412
413 evsel__set_sample_bit(cycles_evsel, CPU);
414 evsel__set_sample_bit(cycles_evsel, TIME);
415
416 /* Fourth event */
417 err = parse_event(evlist, "dummy:u");
418 if (err) {
419 pr_debug("Failed to parse event dummy:u\n");
420 goto out_err;
421 }
422
423 tracking_evsel = evlist__last(evlist);
424
425 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 evsel__set_sample_bit(tracking_evsel, TIME);
431
432 /* Config events */
433 evlist__config(evlist, &opts, NULL);
434
435 /* Check moved event is still at the front */
436 if (cycles_evsel != 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 = evlist__mmap(evlist, UINT_MAX);
464 if (err) {
465 pr_debug("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 }
576 perf_cpu_map__put(cpus);
577 perf_thread_map__put(threads);
578
579 return err;
580
581 out_err:
582 err = -1;
583 goto out;
584 }
585
586 DEFINE_SUITE("Track with sched_switch", switch_tracking);
587
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