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 "pmu.h"
 24
 25static 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
 63struct 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
 74static 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
 92static 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
125static 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
175static 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
209struct event_node {
210	struct list_head list;
211	union perf_event *event;
212	u64 event_time;
213};
214
215static 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
244static 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
255static 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
264static 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;
310out_free:
311	pr_debug("%u events recorded\n", cnt);
312	free(events_array);
313out_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 */
326static 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(NULL);
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	if (perf_pmu__has_hybrid()) {
379		cycles = "cpu_core/cycles/u";
380		err = parse_event(evlist, cycles);
381		if (err) {
382			cycles = "cpu_atom/cycles/u";
383			pr_debug("Trying %s\n", cycles);
384			err = parse_event(evlist, cycles);
385		}
386	} else {
387		err = parse_event(evlist, cycles);
388	}
389	if (err) {
390		pr_debug("Failed to parse event %s\n", cycles);
391		goto out_err;
392	}
393
394	cycles_evsel = evlist__last(evlist);
395
396	/* Third event */
397	if (!evlist__can_select_event(evlist, sched_switch)) {
398		pr_debug("No sched_switch\n");
399		err = 0;
400		goto out;
401	}
402
403	switch_evsel = evlist__add_sched_switch(evlist, true);
404	if (IS_ERR(switch_evsel)) {
405		err = PTR_ERR(switch_evsel);
406		pr_debug("Failed to create event %s\n", sched_switch);
407		goto out_err;
408	}
409
410	switch_evsel->immediate = true;
411
412	/* Test moving an event to the front */
413	if (cycles_evsel == evlist__first(evlist)) {
414		pr_debug("cycles event already at front");
415		goto out_err;
416	}
417	evlist__to_front(evlist, cycles_evsel);
418	if (cycles_evsel != evlist__first(evlist)) {
419		pr_debug("Failed to move cycles event to front");
420		goto out_err;
421	}
422
423	evsel__set_sample_bit(cycles_evsel, CPU);
424	evsel__set_sample_bit(cycles_evsel, TIME);
425
426	/* Fourth event */
427	err = parse_event(evlist, "dummy:u");
428	if (err) {
429		pr_debug("Failed to parse event dummy:u\n");
430		goto out_err;
431	}
432
433	tracking_evsel = evlist__last(evlist);
434
435	evlist__set_tracking_event(evlist, tracking_evsel);
436
437	tracking_evsel->core.attr.freq = 0;
438	tracking_evsel->core.attr.sample_period = 1;
439
440	evsel__set_sample_bit(tracking_evsel, TIME);
441
442	/* Config events */
443	evlist__config(evlist, &opts, NULL);
444
445	/* Check moved event is still at the front */
446	if (cycles_evsel != evlist__first(evlist)) {
447		pr_debug("Front event no longer at front");
448		goto out_err;
449	}
450
451	/* Check tracking event is tracking */
452	if (!tracking_evsel->core.attr.mmap || !tracking_evsel->core.attr.comm) {
453		pr_debug("Tracking event not tracking\n");
454		goto out_err;
455	}
456
457	/* Check non-tracking events are not tracking */
458	evlist__for_each_entry(evlist, evsel) {
459		if (evsel != tracking_evsel) {
460			if (evsel->core.attr.mmap || evsel->core.attr.comm) {
461				pr_debug("Non-tracking event is tracking\n");
462				goto out_err;
463			}
464		}
465	}
466
467	if (evlist__open(evlist) < 0) {
468		pr_debug("Not supported\n");
469		err = 0;
470		goto out;
471	}
472
473	err = evlist__mmap(evlist, UINT_MAX);
474	if (err) {
475		pr_debug("evlist__mmap failed!\n");
476		goto out_err;
477	}
478
479	evlist__enable(evlist);
480
481	err = evsel__disable(cpu_clocks_evsel);
482	if (err) {
483		pr_debug("perf_evlist__disable_event failed!\n");
484		goto out_err;
485	}
486
487	err = spin_sleep();
488	if (err) {
489		pr_debug("spin_sleep failed!\n");
490		goto out_err;
491	}
492
493	comm = "Test COMM 1";
494	err = prctl(PR_SET_NAME, (unsigned long)comm, 0, 0, 0);
495	if (err) {
496		pr_debug("PR_SET_NAME failed!\n");
497		goto out_err;
498	}
499
500	err = evsel__disable(cycles_evsel);
501	if (err) {
502		pr_debug("perf_evlist__disable_event failed!\n");
503		goto out_err;
504	}
505
506	comm = "Test COMM 2";
507	err = prctl(PR_SET_NAME, (unsigned long)comm, 0, 0, 0);
508	if (err) {
509		pr_debug("PR_SET_NAME failed!\n");
510		goto out_err;
511	}
512
513	err = spin_sleep();
514	if (err) {
515		pr_debug("spin_sleep failed!\n");
516		goto out_err;
517	}
518
519	comm = "Test COMM 3";
520	err = prctl(PR_SET_NAME, (unsigned long)comm, 0, 0, 0);
521	if (err) {
522		pr_debug("PR_SET_NAME failed!\n");
523		goto out_err;
524	}
525
526	err = evsel__enable(cycles_evsel);
527	if (err) {
528		pr_debug("perf_evlist__disable_event failed!\n");
529		goto out_err;
530	}
531
532	comm = "Test COMM 4";
533	err = prctl(PR_SET_NAME, (unsigned long)comm, 0, 0, 0);
534	if (err) {
535		pr_debug("PR_SET_NAME failed!\n");
536		goto out_err;
537	}
538
539	err = spin_sleep();
540	if (err) {
541		pr_debug("spin_sleep failed!\n");
542		goto out_err;
543	}
544
545	evlist__disable(evlist);
546
547	switch_tracking.switch_evsel = switch_evsel;
548	switch_tracking.cycles_evsel = cycles_evsel;
549
550	err = process_events(evlist, &switch_tracking);
551
552	zfree(&switch_tracking.tids);
553
554	if (err)
555		goto out_err;
556
557	/* Check all 4 comm events were seen i.e. that evsel->tracking works */
558	if (!switch_tracking.comm_seen[0] || !switch_tracking.comm_seen[1] ||
559	    !switch_tracking.comm_seen[2] || !switch_tracking.comm_seen[3]) {
560		pr_debug("Missing comm events\n");
561		goto out_err;
562	}
563
564	/* Check cycles event got enabled */
565	if (!switch_tracking.cycles_before_comm_1) {
566		pr_debug("Missing cycles events\n");
567		goto out_err;
568	}
569
570	/* Check cycles event got disabled */
571	if (switch_tracking.cycles_between_comm_2_and_comm_3) {
572		pr_debug("cycles events even though event was disabled\n");
573		goto out_err;
574	}
575
576	/* Check cycles event got enabled again */
577	if (!switch_tracking.cycles_after_comm_4) {
578		pr_debug("Missing cycles events\n");
579		goto out_err;
580	}
581out:
582	if (evlist) {
583		evlist__disable(evlist);
584		evlist__delete(evlist);
585	}
586	perf_cpu_map__put(cpus);
587	perf_thread_map__put(threads);
588
589	return err;
590
591out_err:
592	err = -1;
593	goto out;
594}
595
596DEFINE_SUITE("Track with sched_switch", switch_tracking);