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 <perf/cpumap.h>
 10#include <perf/evlist.h>
 11#include <perf/mmap.h>
 12
 13#include "debug.h"
 14#include "parse-events.h"
 15#include "evlist.h"
 16#include "evsel.h"
 17#include "thread_map.h"
 18#include "record.h"
 19#include "tests.h"
 20#include "util/mmap.h"
 21#include "pmu.h"
 22
 23static int spin_sleep(void)
 24{
 25	struct timeval start, now, diff, maxtime;
 26	struct timespec ts;
 27	int err, i;
 28
 29	maxtime.tv_sec = 0;
 30	maxtime.tv_usec = 50000;
 31
 32	err = gettimeofday(&start, NULL);
 33	if (err)
 34		return err;
 35
 36	/* Spin for 50ms */
 37	while (1) {
 38		for (i = 0; i < 1000; i++)
 39			barrier();
 40
 41		err = gettimeofday(&now, NULL);
 42		if (err)
 43			return err;
 44
 45		timersub(&now, &start, &diff);
 46		if (timercmp(&diff, &maxtime, > /* For checkpatch */))
 47			break;
 48	}
 49
 50	ts.tv_nsec = 50 * 1000 * 1000;
 51	ts.tv_sec = 0;
 52
 53	/* Sleep for 50ms */
 54	err = nanosleep(&ts, NULL);
 55	if (err == EINTR)
 56		err = 0;
 57
 58	return err;
 59}
 60
 61struct switch_tracking {
 62	struct evsel *switch_evsel;
 63	struct evsel *cycles_evsel;
 64	pid_t *tids;
 65	int nr_tids;
 66	int comm_seen[4];
 67	int cycles_before_comm_1;
 68	int cycles_between_comm_2_and_comm_3;
 69	int cycles_after_comm_4;
 70};
 71
 72static int check_comm(struct switch_tracking *switch_tracking,
 73		      union perf_event *event, const char *comm, int nr)
 74{
 75	if (event->header.type == PERF_RECORD_COMM &&
 76	    (pid_t)event->comm.pid == getpid() &&
 77	    (pid_t)event->comm.tid == getpid() &&
 78	    strcmp(event->comm.comm, comm) == 0) {
 79		if (switch_tracking->comm_seen[nr]) {
 80			pr_debug("Duplicate comm event\n");
 81			return -1;
 82		}
 83		switch_tracking->comm_seen[nr] = 1;
 84		pr_debug3("comm event: %s nr: %d\n", event->comm.comm, nr);
 85		return 1;
 86	}
 87	return 0;
 88}
 89
 90static int check_cpu(struct switch_tracking *switch_tracking, int cpu)
 91{
 92	int i, nr = cpu + 1;
 93
 94	if (cpu < 0)
 95		return -1;
 96
 97	if (!switch_tracking->tids) {
 98		switch_tracking->tids = calloc(nr, sizeof(pid_t));
 99		if (!switch_tracking->tids)
100			return -1;
101		for (i = 0; i < nr; i++)
102			switch_tracking->tids[i] = -1;
103		switch_tracking->nr_tids = nr;
104		return 0;
105	}
106
107	if (cpu >= switch_tracking->nr_tids) {
108		void *addr;
109
110		addr = realloc(switch_tracking->tids, nr * sizeof(pid_t));
111		if (!addr)
112			return -1;
113		switch_tracking->tids = addr;
114		for (i = switch_tracking->nr_tids; i < nr; i++)
115			switch_tracking->tids[i] = -1;
116		switch_tracking->nr_tids = nr;
117		return 0;
118	}
119
120	return 0;
121}
122
123static int process_sample_event(struct evlist *evlist,
124				union perf_event *event,
125				struct switch_tracking *switch_tracking)
126{
127	struct perf_sample sample;
128	struct evsel *evsel;
129	pid_t next_tid, prev_tid;
130	int cpu, err;
131
132	if (evlist__parse_sample(evlist, event, &sample)) {
133		pr_debug("evlist__parse_sample failed\n");
134		return -1;
135	}
136
137	evsel = evlist__id2evsel(evlist, sample.id);
138	if (evsel == switch_tracking->switch_evsel) {
139		next_tid = evsel__intval(evsel, &sample, "next_pid");
140		prev_tid = evsel__intval(evsel, &sample, "prev_pid");
141		cpu = sample.cpu;
142		pr_debug3("sched_switch: cpu: %d prev_tid %d next_tid %d\n",
143			  cpu, prev_tid, next_tid);
144		err = check_cpu(switch_tracking, cpu);
145		if (err)
146			return err;
147		/*
148		 * Check for no missing sched_switch events i.e. that the
149		 * evsel->core.system_wide flag has worked.
150		 */
151		if (switch_tracking->tids[cpu] != -1 &&
152		    switch_tracking->tids[cpu] != prev_tid) {
153			pr_debug("Missing sched_switch events\n");
154			return -1;
155		}
156		switch_tracking->tids[cpu] = next_tid;
157	}
158
159	if (evsel == switch_tracking->cycles_evsel) {
160		pr_debug3("cycles event\n");
161		if (!switch_tracking->comm_seen[0])
162			switch_tracking->cycles_before_comm_1 = 1;
163		if (switch_tracking->comm_seen[1] &&
164		    !switch_tracking->comm_seen[2])
165			switch_tracking->cycles_between_comm_2_and_comm_3 = 1;
166		if (switch_tracking->comm_seen[3])
167			switch_tracking->cycles_after_comm_4 = 1;
168	}
169
170	return 0;
171}
172
173static int process_event(struct evlist *evlist, union perf_event *event,
174			 struct switch_tracking *switch_tracking)
175{
176	if (event->header.type == PERF_RECORD_SAMPLE)
177		return process_sample_event(evlist, event, switch_tracking);
178
179	if (event->header.type == PERF_RECORD_COMM) {
180		int err, done = 0;
181
182		err = check_comm(switch_tracking, event, "Test COMM 1", 0);
183		if (err < 0)
184			return -1;
185		done += err;
186		err = check_comm(switch_tracking, event, "Test COMM 2", 1);
187		if (err < 0)
188			return -1;
189		done += err;
190		err = check_comm(switch_tracking, event, "Test COMM 3", 2);
191		if (err < 0)
192			return -1;
193		done += err;
194		err = check_comm(switch_tracking, event, "Test COMM 4", 3);
195		if (err < 0)
196			return -1;
197		done += err;
198		if (done != 1) {
199			pr_debug("Unexpected comm event\n");
200			return -1;
201		}
202	}
203
204	return 0;
205}
206
207struct event_node {
208	struct list_head list;
209	union perf_event *event;
210	u64 event_time;
211};
212
213static int add_event(struct evlist *evlist, struct list_head *events,
214		     union perf_event *event)
215{
216	struct perf_sample sample;
217	struct event_node *node;
218
219	node = malloc(sizeof(struct event_node));
220	if (!node) {
221		pr_debug("malloc failed\n");
222		return -1;
223	}
224	node->event = event;
225	list_add(&node->list, events);
226
227	if (evlist__parse_sample(evlist, event, &sample)) {
228		pr_debug("evlist__parse_sample failed\n");
229		return -1;
230	}
231
232	if (!sample.time) {
233		pr_debug("event with no time\n");
234		return -1;
235	}
236
237	node->event_time = sample.time;
238
239	return 0;
240}
241
242static void free_event_nodes(struct list_head *events)
243{
244	struct event_node *node;
245
246	while (!list_empty(events)) {
247		node = list_entry(events->next, struct event_node, list);
248		list_del_init(&node->list);
249		free(node);
250	}
251}
252
253static int compar(const void *a, const void *b)
254{
255	const struct event_node *nodea = a;
256	const struct event_node *nodeb = b;
257	s64 cmp = nodea->event_time - nodeb->event_time;
258
259	return cmp;
260}
261
262static int process_events(struct evlist *evlist,
263			  struct switch_tracking *switch_tracking)
264{
265	union perf_event *event;
266	unsigned pos, cnt = 0;
267	LIST_HEAD(events);
268	struct event_node *events_array, *node;
269	struct mmap *md;
270	int i, ret;
271
272	for (i = 0; i < evlist->core.nr_mmaps; i++) {
273		md = &evlist->mmap[i];
274		if (perf_mmap__read_init(&md->core) < 0)
275			continue;
276
277		while ((event = perf_mmap__read_event(&md->core)) != NULL) {
278			cnt += 1;
279			ret = add_event(evlist, &events, event);
280			 perf_mmap__consume(&md->core);
281			if (ret < 0)
282				goto out_free_nodes;
283		}
284		perf_mmap__read_done(&md->core);
285	}
286
287	events_array = calloc(cnt, sizeof(struct event_node));
288	if (!events_array) {
289		pr_debug("calloc failed\n");
290		ret = -1;
291		goto out_free_nodes;
292	}
293
294	pos = 0;
295	list_for_each_entry(node, &events, list)
296		events_array[pos++] = *node;
297
298	qsort(events_array, cnt, sizeof(struct event_node), compar);
299
300	for (pos = 0; pos < cnt; pos++) {
301		ret = process_event(evlist, events_array[pos].event,
302				    switch_tracking);
303		if (ret < 0)
304			goto out_free;
305	}
306
307	ret = 0;
308out_free:
309	pr_debug("%u events recorded\n", cnt);
310	free(events_array);
311out_free_nodes:
312	free_event_nodes(&events);
313	return ret;
314}
315
316/**
317 * test__switch_tracking - test using sched_switch and tracking events.
318 *
319 * This function implements a test that checks that sched_switch events and
320 * tracking events can be recorded for a workload (current process) using the
321 * evsel->core.system_wide and evsel->tracking flags (respectively) with other events
322 * sometimes enabled or disabled.
323 */
324int test__switch_tracking(struct test *test __maybe_unused, int subtest __maybe_unused)
325{
326	const char *sched_switch = "sched:sched_switch";
327	struct switch_tracking switch_tracking = { .tids = NULL, };
328	struct record_opts opts = {
329		.mmap_pages	     = UINT_MAX,
330		.user_freq	     = UINT_MAX,
331		.user_interval	     = ULLONG_MAX,
332		.freq		     = 4000,
333		.target		     = {
334			.uses_mmap   = true,
335		},
336	};
337	struct perf_thread_map *threads = NULL;
338	struct perf_cpu_map *cpus = NULL;
339	struct evlist *evlist = NULL;
340	struct evsel *evsel, *cpu_clocks_evsel, *cycles_evsel;
341	struct evsel *switch_evsel, *tracking_evsel;
342	const char *comm;
343	int err = -1;
344
345	threads = thread_map__new(-1, getpid(), UINT_MAX);
346	if (!threads) {
347		pr_debug("thread_map__new failed!\n");
348		goto out_err;
349	}
350
351	cpus = perf_cpu_map__new(NULL);
352	if (!cpus) {
353		pr_debug("perf_cpu_map__new failed!\n");
354		goto out_err;
355	}
356
357	evlist = evlist__new();
358	if (!evlist) {
359		pr_debug("evlist__new failed!\n");
360		goto out_err;
361	}
362
363	perf_evlist__set_maps(&evlist->core, cpus, threads);
364
365	/* First event */
366	err = parse_events(evlist, "cpu-clock:u", NULL);
367	if (err) {
368		pr_debug("Failed to parse event dummy:u\n");
369		goto out_err;
370	}
371
372	cpu_clocks_evsel = evlist__last(evlist);
373
374	/* Second event */
375	if (perf_pmu__has_hybrid())
376		err = parse_events(evlist, "cpu_core/cycles/u", NULL);
377	else
378		err = parse_events(evlist, "cycles:u", NULL);
379	if (err) {
380		pr_debug("Failed to parse event cycles:u\n");
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	err = parse_events(evlist, sched_switch, NULL);
394	if (err) {
395		pr_debug("Failed to parse event %s\n", sched_switch);
396		goto out_err;
397	}
398
399	switch_evsel = evlist__last(evlist);
400
401	evsel__set_sample_bit(switch_evsel, CPU);
402	evsel__set_sample_bit(switch_evsel, TIME);
403
404	switch_evsel->core.system_wide = true;
405	switch_evsel->no_aux_samples = true;
406	switch_evsel->immediate = true;
407
408	/* Test moving an event to the front */
409	if (cycles_evsel == evlist__first(evlist)) {
410		pr_debug("cycles event already at front");
411		goto out_err;
412	}
413	evlist__to_front(evlist, cycles_evsel);
414	if (cycles_evsel != evlist__first(evlist)) {
415		pr_debug("Failed to move cycles event to front");
416		goto out_err;
417	}
418
419	evsel__set_sample_bit(cycles_evsel, CPU);
420	evsel__set_sample_bit(cycles_evsel, TIME);
421
422	/* Fourth event */
423	err = parse_events(evlist, "dummy:u", NULL);
424	if (err) {
425		pr_debug("Failed to parse event dummy:u\n");
426		goto out_err;
427	}
428
429	tracking_evsel = evlist__last(evlist);
430
431	evlist__set_tracking_event(evlist, tracking_evsel);
432
433	tracking_evsel->core.attr.freq = 0;
434	tracking_evsel->core.attr.sample_period = 1;
435
436	evsel__set_sample_bit(tracking_evsel, TIME);
437
438	/* Config events */
439	evlist__config(evlist, &opts, NULL);
440
441	/* Check moved event is still at the front */
442	if (cycles_evsel != evlist__first(evlist)) {
443		pr_debug("Front event no longer at front");
444		goto out_err;
445	}
446
447	/* Check tracking event is tracking */
448	if (!tracking_evsel->core.attr.mmap || !tracking_evsel->core.attr.comm) {
449		pr_debug("Tracking event not tracking\n");
450		goto out_err;
451	}
452
453	/* Check non-tracking events are not tracking */
454	evlist__for_each_entry(evlist, evsel) {
455		if (evsel != tracking_evsel) {
456			if (evsel->core.attr.mmap || evsel->core.attr.comm) {
457				pr_debug("Non-tracking event is tracking\n");
458				goto out_err;
459			}
460		}
461	}
462
463	if (evlist__open(evlist) < 0) {
464		pr_debug("Not supported\n");
465		err = 0;
466		goto out;
467	}
468
469	err = evlist__mmap(evlist, UINT_MAX);
470	if (err) {
471		pr_debug("evlist__mmap failed!\n");
472		goto out_err;
473	}
474
475	evlist__enable(evlist);
476
477	err = evsel__disable(cpu_clocks_evsel);
478	if (err) {
479		pr_debug("perf_evlist__disable_event failed!\n");
480		goto out_err;
481	}
482
483	err = spin_sleep();
484	if (err) {
485		pr_debug("spin_sleep failed!\n");
486		goto out_err;
487	}
488
489	comm = "Test COMM 1";
490	err = prctl(PR_SET_NAME, (unsigned long)comm, 0, 0, 0);
491	if (err) {
492		pr_debug("PR_SET_NAME failed!\n");
493		goto out_err;
494	}
495
496	err = evsel__disable(cycles_evsel);
497	if (err) {
498		pr_debug("perf_evlist__disable_event failed!\n");
499		goto out_err;
500	}
501
502	comm = "Test COMM 2";
503	err = prctl(PR_SET_NAME, (unsigned long)comm, 0, 0, 0);
504	if (err) {
505		pr_debug("PR_SET_NAME failed!\n");
506		goto out_err;
507	}
508
509	err = spin_sleep();
510	if (err) {
511		pr_debug("spin_sleep failed!\n");
512		goto out_err;
513	}
514
515	comm = "Test COMM 3";
516	err = prctl(PR_SET_NAME, (unsigned long)comm, 0, 0, 0);
517	if (err) {
518		pr_debug("PR_SET_NAME failed!\n");
519		goto out_err;
520	}
521
522	err = evsel__enable(cycles_evsel);
523	if (err) {
524		pr_debug("perf_evlist__disable_event failed!\n");
525		goto out_err;
526	}
527
528	comm = "Test COMM 4";
529	err = prctl(PR_SET_NAME, (unsigned long)comm, 0, 0, 0);
530	if (err) {
531		pr_debug("PR_SET_NAME failed!\n");
532		goto out_err;
533	}
534
535	err = spin_sleep();
536	if (err) {
537		pr_debug("spin_sleep failed!\n");
538		goto out_err;
539	}
540
541	evlist__disable(evlist);
542
543	switch_tracking.switch_evsel = switch_evsel;
544	switch_tracking.cycles_evsel = cycles_evsel;
545
546	err = process_events(evlist, &switch_tracking);
547
548	zfree(&switch_tracking.tids);
549
550	if (err)
551		goto out_err;
552
553	/* Check all 4 comm events were seen i.e. that evsel->tracking works */
554	if (!switch_tracking.comm_seen[0] || !switch_tracking.comm_seen[1] ||
555	    !switch_tracking.comm_seen[2] || !switch_tracking.comm_seen[3]) {
556		pr_debug("Missing comm events\n");
557		goto out_err;
558	}
559
560	/* Check cycles event got enabled */
561	if (!switch_tracking.cycles_before_comm_1) {
562		pr_debug("Missing cycles events\n");
563		goto out_err;
564	}
565
566	/* Check cycles event got disabled */
567	if (switch_tracking.cycles_between_comm_2_and_comm_3) {
568		pr_debug("cycles events even though event was disabled\n");
569		goto out_err;
570	}
571
572	/* Check cycles event got enabled again */
573	if (!switch_tracking.cycles_after_comm_4) {
574		pr_debug("Missing cycles events\n");
575		goto out_err;
576	}
577out:
578	if (evlist) {
579		evlist__disable(evlist);
580		evlist__delete(evlist);
581	}
582	perf_cpu_map__put(cpus);
583	perf_thread_map__put(threads);
584
585	return err;
586
587out_err:
588	err = -1;
589	goto out;
590}