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 "pmu.h"
23
spin_sleep(void)24 static int spin_sleep(void)
25 {
26 struct timeval start, now, diff, maxtime;
27 struct timespec ts;
28 int err, i;
29
30 maxtime.tv_sec = 0;
31 maxtime.tv_usec = 50000;
32
33 err = gettimeofday(&start, NULL);
34 if (err)
35 return err;
36
37 /* Spin for 50ms */
38 while (1) {
39 for (i = 0; i < 1000; i++)
40 barrier();
41
42 err = gettimeofday(&now, NULL);
43 if (err)
44 return err;
45
46 timersub(&now, &start, &diff);
47 if (timercmp(&diff, &maxtime, > /* For checkpatch */))
48 break;
49 }
50
51 ts.tv_nsec = 50 * 1000 * 1000;
52 ts.tv_sec = 0;
53
54 /* Sleep for 50ms */
55 err = nanosleep(&ts, NULL);
56 if (err == EINTR)
57 err = 0;
58
59 return err;
60 }
61
62 struct switch_tracking {
63 struct evsel *switch_evsel;
64 struct evsel *cycles_evsel;
65 pid_t *tids;
66 int nr_tids;
67 int comm_seen[4];
68 int cycles_before_comm_1;
69 int cycles_between_comm_2_and_comm_3;
70 int cycles_after_comm_4;
71 };
72
check_comm(struct switch_tracking * switch_tracking,union perf_event * event,const char * comm,int nr)73 static int check_comm(struct switch_tracking *switch_tracking,
74 union perf_event *event, const char *comm, int nr)
75 {
76 if (event->header.type == PERF_RECORD_COMM &&
77 (pid_t)event->comm.pid == getpid() &&
78 (pid_t)event->comm.tid == getpid() &&
79 strcmp(event->comm.comm, comm) == 0) {
80 if (switch_tracking->comm_seen[nr]) {
81 pr_debug("Duplicate comm event\n");
82 return -1;
83 }
84 switch_tracking->comm_seen[nr] = 1;
85 pr_debug3("comm event: %s nr: %d\n", event->comm.comm, nr);
86 return 1;
87 }
88 return 0;
89 }
90
check_cpu(struct switch_tracking * switch_tracking,int cpu)91 static int check_cpu(struct switch_tracking *switch_tracking, int cpu)
92 {
93 int i, nr = cpu + 1;
94
95 if (cpu < 0)
96 return -1;
97
98 if (!switch_tracking->tids) {
99 switch_tracking->tids = calloc(nr, sizeof(pid_t));
100 if (!switch_tracking->tids)
101 return -1;
102 for (i = 0; i < nr; i++)
103 switch_tracking->tids[i] = -1;
104 switch_tracking->nr_tids = nr;
105 return 0;
106 }
107
108 if (cpu >= switch_tracking->nr_tids) {
109 void *addr;
110
111 addr = realloc(switch_tracking->tids, nr * sizeof(pid_t));
112 if (!addr)
113 return -1;
114 switch_tracking->tids = addr;
115 for (i = switch_tracking->nr_tids; i < nr; i++)
116 switch_tracking->tids[i] = -1;
117 switch_tracking->nr_tids = nr;
118 return 0;
119 }
120
121 return 0;
122 }
123
process_sample_event(struct evlist * evlist,union perf_event * event,struct switch_tracking * switch_tracking)124 static int process_sample_event(struct evlist *evlist,
125 union perf_event *event,
126 struct switch_tracking *switch_tracking)
127 {
128 struct perf_sample sample;
129 struct evsel *evsel;
130 pid_t next_tid, prev_tid;
131 int cpu, err;
132
133 if (evlist__parse_sample(evlist, event, &sample)) {
134 pr_debug("evlist__parse_sample failed\n");
135 return -1;
136 }
137
138 evsel = evlist__id2evsel(evlist, sample.id);
139 if (evsel == switch_tracking->switch_evsel) {
140 next_tid = evsel__intval(evsel, &sample, "next_pid");
141 prev_tid = evsel__intval(evsel, &sample, "prev_pid");
142 cpu = sample.cpu;
143 pr_debug3("sched_switch: cpu: %d prev_tid %d next_tid %d\n",
144 cpu, prev_tid, next_tid);
145 err = check_cpu(switch_tracking, cpu);
146 if (err)
147 return err;
148 /*
149 * Check for no missing sched_switch events i.e. that the
150 * evsel->core.system_wide flag has worked.
151 */
152 if (switch_tracking->tids[cpu] != -1 &&
153 switch_tracking->tids[cpu] != prev_tid) {
154 pr_debug("Missing sched_switch events\n");
155 return -1;
156 }
157 switch_tracking->tids[cpu] = next_tid;
158 }
159
160 if (evsel == switch_tracking->cycles_evsel) {
161 pr_debug3("cycles event\n");
162 if (!switch_tracking->comm_seen[0])
163 switch_tracking->cycles_before_comm_1 = 1;
164 if (switch_tracking->comm_seen[1] &&
165 !switch_tracking->comm_seen[2])
166 switch_tracking->cycles_between_comm_2_and_comm_3 = 1;
167 if (switch_tracking->comm_seen[3])
168 switch_tracking->cycles_after_comm_4 = 1;
169 }
170
171 return 0;
172 }
173
process_event(struct evlist * evlist,union perf_event * event,struct switch_tracking * switch_tracking)174 static int process_event(struct evlist *evlist, union perf_event *event,
175 struct switch_tracking *switch_tracking)
176 {
177 if (event->header.type == PERF_RECORD_SAMPLE)
178 return process_sample_event(evlist, event, switch_tracking);
179
180 if (event->header.type == PERF_RECORD_COMM) {
181 int err, done = 0;
182
183 err = check_comm(switch_tracking, event, "Test COMM 1", 0);
184 if (err < 0)
185 return -1;
186 done += err;
187 err = check_comm(switch_tracking, event, "Test COMM 2", 1);
188 if (err < 0)
189 return -1;
190 done += err;
191 err = check_comm(switch_tracking, event, "Test COMM 3", 2);
192 if (err < 0)
193 return -1;
194 done += err;
195 err = check_comm(switch_tracking, event, "Test COMM 4", 3);
196 if (err < 0)
197 return -1;
198 done += err;
199 if (done != 1) {
200 pr_debug("Unexpected comm event\n");
201 return -1;
202 }
203 }
204
205 return 0;
206 }
207
208 struct event_node {
209 struct list_head list;
210 union perf_event *event;
211 u64 event_time;
212 };
213
add_event(struct evlist * evlist,struct list_head * events,union perf_event * event)214 static int add_event(struct evlist *evlist, struct list_head *events,
215 union perf_event *event)
216 {
217 struct perf_sample sample;
218 struct event_node *node;
219
220 node = malloc(sizeof(struct event_node));
221 if (!node) {
222 pr_debug("malloc failed\n");
223 return -1;
224 }
225 node->event = event;
226 list_add(&node->list, events);
227
228 if (evlist__parse_sample(evlist, event, &sample)) {
229 pr_debug("evlist__parse_sample failed\n");
230 return -1;
231 }
232
233 if (!sample.time) {
234 pr_debug("event with no time\n");
235 return -1;
236 }
237
238 node->event_time = sample.time;
239
240 return 0;
241 }
242
free_event_nodes(struct list_head * events)243 static void free_event_nodes(struct list_head *events)
244 {
245 struct event_node *node;
246
247 while (!list_empty(events)) {
248 node = list_entry(events->next, struct event_node, list);
249 list_del_init(&node->list);
250 free(node);
251 }
252 }
253
compar(const void * a,const void * b)254 static int compar(const void *a, const void *b)
255 {
256 const struct event_node *nodea = a;
257 const struct event_node *nodeb = b;
258 s64 cmp = nodea->event_time - nodeb->event_time;
259
260 return cmp;
261 }
262
process_events(struct evlist * evlist,struct switch_tracking * switch_tracking)263 static int process_events(struct evlist *evlist,
264 struct switch_tracking *switch_tracking)
265 {
266 union perf_event *event;
267 unsigned pos, cnt = 0;
268 LIST_HEAD(events);
269 struct event_node *events_array, *node;
270 struct mmap *md;
271 int i, ret;
272
273 for (i = 0; i < evlist->core.nr_mmaps; i++) {
274 md = &evlist->mmap[i];
275 if (perf_mmap__read_init(&md->core) < 0)
276 continue;
277
278 while ((event = perf_mmap__read_event(&md->core)) != NULL) {
279 cnt += 1;
280 ret = add_event(evlist, &events, event);
281 perf_mmap__consume(&md->core);
282 if (ret < 0)
283 goto out_free_nodes;
284 }
285 perf_mmap__read_done(&md->core);
286 }
287
288 events_array = calloc(cnt, sizeof(struct event_node));
289 if (!events_array) {
290 pr_debug("calloc failed\n");
291 ret = -1;
292 goto out_free_nodes;
293 }
294
295 pos = 0;
296 list_for_each_entry(node, &events, list)
297 events_array[pos++] = *node;
298
299 qsort(events_array, cnt, sizeof(struct event_node), compar);
300
301 for (pos = 0; pos < cnt; pos++) {
302 ret = process_event(evlist, events_array[pos].event,
303 switch_tracking);
304 if (ret < 0)
305 goto out_free;
306 }
307
308 ret = 0;
309 out_free:
310 pr_debug("%u events recorded\n", cnt);
311 free(events_array);
312 out_free_nodes:
313 free_event_nodes(&events);
314 return ret;
315 }
316
317 /**
318 * test__switch_tracking - test using sched_switch and tracking events.
319 *
320 * This function implements a test that checks that sched_switch events and
321 * tracking events can be recorded for a workload (current process) using the
322 * evsel->core.system_wide and evsel->tracking flags (respectively) with other events
323 * sometimes enabled or disabled.
324 */
test__switch_tracking(struct test_suite * test __maybe_unused,int subtest __maybe_unused)325 static int test__switch_tracking(struct test_suite *test __maybe_unused, int subtest __maybe_unused)
326 {
327 const char *sched_switch = "sched:sched_switch";
328 const char *cycles = "cycles:u";
329 struct switch_tracking switch_tracking = { .tids = NULL, };
330 struct record_opts opts = {
331 .mmap_pages = UINT_MAX,
332 .user_freq = UINT_MAX,
333 .user_interval = ULLONG_MAX,
334 .freq = 4000,
335 .target = {
336 .uses_mmap = true,
337 },
338 };
339 struct perf_thread_map *threads = NULL;
340 struct perf_cpu_map *cpus = NULL;
341 struct evlist *evlist = NULL;
342 struct evsel *evsel, *cpu_clocks_evsel, *cycles_evsel;
343 struct evsel *switch_evsel, *tracking_evsel;
344 const char *comm;
345 int err = -1;
346
347 threads = thread_map__new(-1, getpid(), UINT_MAX);
348 if (!threads) {
349 pr_debug("thread_map__new failed!\n");
350 goto out_err;
351 }
352
353 cpus = perf_cpu_map__new(NULL);
354 if (!cpus) {
355 pr_debug("perf_cpu_map__new failed!\n");
356 goto out_err;
357 }
358
359 evlist = evlist__new();
360 if (!evlist) {
361 pr_debug("evlist__new failed!\n");
362 goto out_err;
363 }
364
365 perf_evlist__set_maps(&evlist->core, cpus, threads);
366
367 /* First event */
368 err = parse_event(evlist, "cpu-clock:u");
369 if (err) {
370 pr_debug("Failed to parse event dummy:u\n");
371 goto out_err;
372 }
373
374 cpu_clocks_evsel = evlist__last(evlist);
375
376 /* Second event */
377 if (perf_pmu__has_hybrid()) {
378 cycles = "cpu_core/cycles/u";
379 err = parse_event(evlist, cycles);
380 if (err) {
381 cycles = "cpu_atom/cycles/u";
382 pr_debug("Trying %s\n", cycles);
383 err = parse_event(evlist, cycles);
384 }
385 } else {
386 err = parse_event(evlist, cycles);
387 }
388 if (err) {
389 pr_debug("Failed to parse event %s\n", cycles);
390 goto out_err;
391 }
392
393 cycles_evsel = evlist__last(evlist);
394
395 /* Third event */
396 if (!evlist__can_select_event(evlist, sched_switch)) {
397 pr_debug("No sched_switch\n");
398 err = 0;
399 goto out;
400 }
401
402 switch_evsel = evlist__add_sched_switch(evlist, true);
403 if (IS_ERR(switch_evsel)) {
404 err = PTR_ERR(switch_evsel);
405 pr_debug("Failed to create event %s\n", sched_switch);
406 goto out_err;
407 }
408
409 switch_evsel->immediate = true;
410
411 /* Test moving an event to the front */
412 if (cycles_evsel == evlist__first(evlist)) {
413 pr_debug("cycles event already at front");
414 goto out_err;
415 }
416 evlist__to_front(evlist, cycles_evsel);
417 if (cycles_evsel != evlist__first(evlist)) {
418 pr_debug("Failed to move cycles event to front");
419 goto out_err;
420 }
421
422 evsel__set_sample_bit(cycles_evsel, CPU);
423 evsel__set_sample_bit(cycles_evsel, TIME);
424
425 /* Fourth event */
426 err = parse_event(evlist, "dummy:u");
427 if (err) {
428 pr_debug("Failed to parse event dummy:u\n");
429 goto out_err;
430 }
431
432 tracking_evsel = evlist__last(evlist);
433
434 evlist__set_tracking_event(evlist, tracking_evsel);
435
436 tracking_evsel->core.attr.freq = 0;
437 tracking_evsel->core.attr.sample_period = 1;
438
439 evsel__set_sample_bit(tracking_evsel, TIME);
440
441 /* Config events */
442 evlist__config(evlist, &opts, NULL);
443
444 /* Check moved event is still at the front */
445 if (cycles_evsel != evlist__first(evlist)) {
446 pr_debug("Front event no longer at front");
447 goto out_err;
448 }
449
450 /* Check tracking event is tracking */
451 if (!tracking_evsel->core.attr.mmap || !tracking_evsel->core.attr.comm) {
452 pr_debug("Tracking event not tracking\n");
453 goto out_err;
454 }
455
456 /* Check non-tracking events are not tracking */
457 evlist__for_each_entry(evlist, evsel) {
458 if (evsel != tracking_evsel) {
459 if (evsel->core.attr.mmap || evsel->core.attr.comm) {
460 pr_debug("Non-tracking event is tracking\n");
461 goto out_err;
462 }
463 }
464 }
465
466 if (evlist__open(evlist) < 0) {
467 pr_debug("Not supported\n");
468 err = 0;
469 goto out;
470 }
471
472 err = evlist__mmap(evlist, UINT_MAX);
473 if (err) {
474 pr_debug("evlist__mmap failed!\n");
475 goto out_err;
476 }
477
478 evlist__enable(evlist);
479
480 err = evsel__disable(cpu_clocks_evsel);
481 if (err) {
482 pr_debug("perf_evlist__disable_event failed!\n");
483 goto out_err;
484 }
485
486 err = spin_sleep();
487 if (err) {
488 pr_debug("spin_sleep failed!\n");
489 goto out_err;
490 }
491
492 comm = "Test COMM 1";
493 err = prctl(PR_SET_NAME, (unsigned long)comm, 0, 0, 0);
494 if (err) {
495 pr_debug("PR_SET_NAME failed!\n");
496 goto out_err;
497 }
498
499 err = evsel__disable(cycles_evsel);
500 if (err) {
501 pr_debug("perf_evlist__disable_event failed!\n");
502 goto out_err;
503 }
504
505 comm = "Test COMM 2";
506 err = prctl(PR_SET_NAME, (unsigned long)comm, 0, 0, 0);
507 if (err) {
508 pr_debug("PR_SET_NAME failed!\n");
509 goto out_err;
510 }
511
512 err = spin_sleep();
513 if (err) {
514 pr_debug("spin_sleep failed!\n");
515 goto out_err;
516 }
517
518 comm = "Test COMM 3";
519 err = prctl(PR_SET_NAME, (unsigned long)comm, 0, 0, 0);
520 if (err) {
521 pr_debug("PR_SET_NAME failed!\n");
522 goto out_err;
523 }
524
525 err = evsel__enable(cycles_evsel);
526 if (err) {
527 pr_debug("perf_evlist__disable_event failed!\n");
528 goto out_err;
529 }
530
531 comm = "Test COMM 4";
532 err = prctl(PR_SET_NAME, (unsigned long)comm, 0, 0, 0);
533 if (err) {
534 pr_debug("PR_SET_NAME failed!\n");
535 goto out_err;
536 }
537
538 err = spin_sleep();
539 if (err) {
540 pr_debug("spin_sleep failed!\n");
541 goto out_err;
542 }
543
544 evlist__disable(evlist);
545
546 switch_tracking.switch_evsel = switch_evsel;
547 switch_tracking.cycles_evsel = cycles_evsel;
548
549 err = process_events(evlist, &switch_tracking);
550
551 zfree(&switch_tracking.tids);
552
553 if (err)
554 goto out_err;
555
556 /* Check all 4 comm events were seen i.e. that evsel->tracking works */
557 if (!switch_tracking.comm_seen[0] || !switch_tracking.comm_seen[1] ||
558 !switch_tracking.comm_seen[2] || !switch_tracking.comm_seen[3]) {
559 pr_debug("Missing comm events\n");
560 goto out_err;
561 }
562
563 /* Check cycles event got enabled */
564 if (!switch_tracking.cycles_before_comm_1) {
565 pr_debug("Missing cycles events\n");
566 goto out_err;
567 }
568
569 /* Check cycles event got disabled */
570 if (switch_tracking.cycles_between_comm_2_and_comm_3) {
571 pr_debug("cycles events even though event was disabled\n");
572 goto out_err;
573 }
574
575 /* Check cycles event got enabled again */
576 if (!switch_tracking.cycles_after_comm_4) {
577 pr_debug("Missing cycles events\n");
578 goto out_err;
579 }
580 out:
581 if (evlist) {
582 evlist__disable(evlist);
583 evlist__delete(evlist);
584 }
585 perf_cpu_map__put(cpus);
586 perf_thread_map__put(threads);
587
588 return err;
589
590 out_err:
591 err = -1;
592 goto out;
593 }
594
595 DEFINE_SUITE("Track with sched_switch", switch_tracking);
596