xref: /linux/tools/perf/builtin-record.c (revision d39d0ed196aa1685bb24771e92f78633c66ac9cb)
1 /*
2  * builtin-record.c
3  *
4  * Builtin record command: Record the profile of a workload
5  * (or a CPU, or a PID) into the perf.data output file - for
6  * later analysis via perf report.
7  */
8 #define _FILE_OFFSET_BITS 64
9 
10 #include "builtin.h"
11 
12 #include "perf.h"
13 
14 #include "util/build-id.h"
15 #include "util/util.h"
16 #include "util/parse-options.h"
17 #include "util/parse-events.h"
18 
19 #include "util/header.h"
20 #include "util/event.h"
21 #include "util/debug.h"
22 #include "util/session.h"
23 #include "util/symbol.h"
24 #include "util/cpumap.h"
25 
26 #include <unistd.h>
27 #include <sched.h>
28 #include <sys/mman.h>
29 
30 enum write_mode_t {
31 	WRITE_FORCE,
32 	WRITE_APPEND
33 };
34 
35 static int			*fd[MAX_NR_CPUS][MAX_COUNTERS];
36 
37 static u64			user_interval			= ULLONG_MAX;
38 static u64			default_interval		=      0;
39 
40 static int			nr_cpus				=      0;
41 static unsigned int		page_size;
42 static unsigned int		mmap_pages			=    128;
43 static unsigned int		user_freq 			= UINT_MAX;
44 static int			freq				=   1000;
45 static int			output;
46 static int			pipe_output			=      0;
47 static const char		*output_name			= "perf.data";
48 static int			group				=      0;
49 static int			realtime_prio			=      0;
50 static bool			raw_samples			=  false;
51 static bool			system_wide			=  false;
52 static pid_t			target_pid			=     -1;
53 static pid_t			target_tid			=     -1;
54 static pid_t			*all_tids			=      NULL;
55 static int			thread_num			=      0;
56 static pid_t			child_pid			=     -1;
57 static bool			no_inherit			=  false;
58 static enum write_mode_t	write_mode			= WRITE_FORCE;
59 static bool			call_graph			=  false;
60 static bool			inherit_stat			=  false;
61 static bool			no_samples			=  false;
62 static bool			sample_address			=  false;
63 static bool			no_buildid			=  false;
64 
65 static long			samples				=      0;
66 static u64			bytes_written			=      0;
67 
68 static struct pollfd		*event_array;
69 
70 static int			nr_poll				=      0;
71 static int			nr_cpu				=      0;
72 
73 static int			file_new			=      1;
74 static off_t			post_processing_offset;
75 
76 static struct perf_session	*session;
77 static const char		*cpu_list;
78 
79 struct mmap_data {
80 	int			counter;
81 	void			*base;
82 	unsigned int		mask;
83 	unsigned int		prev;
84 };
85 
86 static struct mmap_data		mmap_array[MAX_NR_CPUS];
87 
88 static unsigned long mmap_read_head(struct mmap_data *md)
89 {
90 	struct perf_event_mmap_page *pc = md->base;
91 	long head;
92 
93 	head = pc->data_head;
94 	rmb();
95 
96 	return head;
97 }
98 
99 static void mmap_write_tail(struct mmap_data *md, unsigned long tail)
100 {
101 	struct perf_event_mmap_page *pc = md->base;
102 
103 	/*
104 	 * ensure all reads are done before we write the tail out.
105 	 */
106 	/* mb(); */
107 	pc->data_tail = tail;
108 }
109 
110 static void advance_output(size_t size)
111 {
112 	bytes_written += size;
113 }
114 
115 static void write_output(void *buf, size_t size)
116 {
117 	while (size) {
118 		int ret = write(output, buf, size);
119 
120 		if (ret < 0)
121 			die("failed to write");
122 
123 		size -= ret;
124 		buf += ret;
125 
126 		bytes_written += ret;
127 	}
128 }
129 
130 static int process_synthesized_event(event_t *event,
131 				     struct perf_session *self __used)
132 {
133 	write_output(event, event->header.size);
134 	return 0;
135 }
136 
137 static void mmap_read(struct mmap_data *md)
138 {
139 	unsigned int head = mmap_read_head(md);
140 	unsigned int old = md->prev;
141 	unsigned char *data = md->base + page_size;
142 	unsigned long size;
143 	void *buf;
144 	int diff;
145 
146 	/*
147 	 * If we're further behind than half the buffer, there's a chance
148 	 * the writer will bite our tail and mess up the samples under us.
149 	 *
150 	 * If we somehow ended up ahead of the head, we got messed up.
151 	 *
152 	 * In either case, truncate and restart at head.
153 	 */
154 	diff = head - old;
155 	if (diff < 0) {
156 		fprintf(stderr, "WARNING: failed to keep up with mmap data\n");
157 		/*
158 		 * head points to a known good entry, start there.
159 		 */
160 		old = head;
161 	}
162 
163 	if (old != head)
164 		samples++;
165 
166 	size = head - old;
167 
168 	if ((old & md->mask) + size != (head & md->mask)) {
169 		buf = &data[old & md->mask];
170 		size = md->mask + 1 - (old & md->mask);
171 		old += size;
172 
173 		write_output(buf, size);
174 	}
175 
176 	buf = &data[old & md->mask];
177 	size = head - old;
178 	old += size;
179 
180 	write_output(buf, size);
181 
182 	md->prev = old;
183 	mmap_write_tail(md, old);
184 }
185 
186 static volatile int done = 0;
187 static volatile int signr = -1;
188 
189 static void sig_handler(int sig)
190 {
191 	done = 1;
192 	signr = sig;
193 }
194 
195 static void sig_atexit(void)
196 {
197 	if (child_pid > 0)
198 		kill(child_pid, SIGTERM);
199 
200 	if (signr == -1)
201 		return;
202 
203 	signal(signr, SIG_DFL);
204 	kill(getpid(), signr);
205 }
206 
207 static int group_fd;
208 
209 static struct perf_header_attr *get_header_attr(struct perf_event_attr *a, int nr)
210 {
211 	struct perf_header_attr *h_attr;
212 
213 	if (nr < session->header.attrs) {
214 		h_attr = session->header.attr[nr];
215 	} else {
216 		h_attr = perf_header_attr__new(a);
217 		if (h_attr != NULL)
218 			if (perf_header__add_attr(&session->header, h_attr) < 0) {
219 				perf_header_attr__delete(h_attr);
220 				h_attr = NULL;
221 			}
222 	}
223 
224 	return h_attr;
225 }
226 
227 static void create_counter(int counter, int cpu)
228 {
229 	char *filter = filters[counter];
230 	struct perf_event_attr *attr = attrs + counter;
231 	struct perf_header_attr *h_attr;
232 	int track = !counter; /* only the first counter needs these */
233 	int thread_index;
234 	int ret;
235 	struct {
236 		u64 count;
237 		u64 time_enabled;
238 		u64 time_running;
239 		u64 id;
240 	} read_data;
241 
242 	attr->read_format	= PERF_FORMAT_TOTAL_TIME_ENABLED |
243 				  PERF_FORMAT_TOTAL_TIME_RUNNING |
244 				  PERF_FORMAT_ID;
245 
246 	attr->sample_type	|= PERF_SAMPLE_IP | PERF_SAMPLE_TID;
247 
248 	if (nr_counters > 1)
249 		attr->sample_type |= PERF_SAMPLE_ID;
250 
251 	/*
252 	 * We default some events to a 1 default interval. But keep
253 	 * it a weak assumption overridable by the user.
254 	 */
255 	if (!attr->sample_period || (user_freq != UINT_MAX &&
256 				     user_interval != ULLONG_MAX)) {
257 		if (freq) {
258 			attr->sample_type	|= PERF_SAMPLE_PERIOD;
259 			attr->freq		= 1;
260 			attr->sample_freq	= freq;
261 		} else {
262 			attr->sample_period = default_interval;
263 		}
264 	}
265 
266 	if (no_samples)
267 		attr->sample_freq = 0;
268 
269 	if (inherit_stat)
270 		attr->inherit_stat = 1;
271 
272 	if (sample_address) {
273 		attr->sample_type	|= PERF_SAMPLE_ADDR;
274 		attr->mmap_data = track;
275 	}
276 
277 	if (call_graph)
278 		attr->sample_type	|= PERF_SAMPLE_CALLCHAIN;
279 
280 	if (system_wide)
281 		attr->sample_type	|= PERF_SAMPLE_CPU;
282 
283 	if (raw_samples) {
284 		attr->sample_type	|= PERF_SAMPLE_TIME;
285 		attr->sample_type	|= PERF_SAMPLE_RAW;
286 		attr->sample_type	|= PERF_SAMPLE_CPU;
287 	}
288 
289 	attr->mmap		= track;
290 	attr->comm		= track;
291 	attr->inherit		= !no_inherit;
292 	if (target_pid == -1 && target_tid == -1 && !system_wide) {
293 		attr->disabled = 1;
294 		attr->enable_on_exec = 1;
295 	}
296 
297 	for (thread_index = 0; thread_index < thread_num; thread_index++) {
298 try_again:
299 		fd[nr_cpu][counter][thread_index] = sys_perf_event_open(attr,
300 				all_tids[thread_index], cpu, group_fd, 0);
301 
302 		if (fd[nr_cpu][counter][thread_index] < 0) {
303 			int err = errno;
304 
305 			if (err == EPERM || err == EACCES)
306 				die("Permission error - are you root?\n"
307 					"\t Consider tweaking"
308 					" /proc/sys/kernel/perf_event_paranoid.\n");
309 			else if (err ==  ENODEV && cpu_list) {
310 				die("No such device - did you specify"
311 					" an out-of-range profile CPU?\n");
312 			}
313 
314 			/*
315 			 * If it's cycles then fall back to hrtimer
316 			 * based cpu-clock-tick sw counter, which
317 			 * is always available even if no PMU support:
318 			 */
319 			if (attr->type == PERF_TYPE_HARDWARE
320 					&& attr->config == PERF_COUNT_HW_CPU_CYCLES) {
321 
322 				if (verbose)
323 					warning(" ... trying to fall back to cpu-clock-ticks\n");
324 				attr->type = PERF_TYPE_SOFTWARE;
325 				attr->config = PERF_COUNT_SW_CPU_CLOCK;
326 				goto try_again;
327 			}
328 			printf("\n");
329 			error("perfcounter syscall returned with %d (%s)\n",
330 					fd[nr_cpu][counter][thread_index], strerror(err));
331 
332 #if defined(__i386__) || defined(__x86_64__)
333 			if (attr->type == PERF_TYPE_HARDWARE && err == EOPNOTSUPP)
334 				die("No hardware sampling interrupt available."
335 				    " No APIC? If so then you can boot the kernel"
336 				    " with the \"lapic\" boot parameter to"
337 				    " force-enable it.\n");
338 #endif
339 
340 			die("No CONFIG_PERF_EVENTS=y kernel support configured?\n");
341 			exit(-1);
342 		}
343 
344 		h_attr = get_header_attr(attr, counter);
345 		if (h_attr == NULL)
346 			die("nomem\n");
347 
348 		if (!file_new) {
349 			if (memcmp(&h_attr->attr, attr, sizeof(*attr))) {
350 				fprintf(stderr, "incompatible append\n");
351 				exit(-1);
352 			}
353 		}
354 
355 		if (read(fd[nr_cpu][counter][thread_index], &read_data, sizeof(read_data)) == -1) {
356 			perror("Unable to read perf file descriptor\n");
357 			exit(-1);
358 		}
359 
360 		if (perf_header_attr__add_id(h_attr, read_data.id) < 0) {
361 			pr_warning("Not enough memory to add id\n");
362 			exit(-1);
363 		}
364 
365 		assert(fd[nr_cpu][counter][thread_index] >= 0);
366 		fcntl(fd[nr_cpu][counter][thread_index], F_SETFL, O_NONBLOCK);
367 
368 		/*
369 		 * First counter acts as the group leader:
370 		 */
371 		if (group && group_fd == -1)
372 			group_fd = fd[nr_cpu][counter][thread_index];
373 
374 		if (counter || thread_index) {
375 			ret = ioctl(fd[nr_cpu][counter][thread_index],
376 					PERF_EVENT_IOC_SET_OUTPUT,
377 					fd[nr_cpu][0][0]);
378 			if (ret) {
379 				error("failed to set output: %d (%s)\n", errno,
380 						strerror(errno));
381 				exit(-1);
382 			}
383 		} else {
384 			mmap_array[nr_cpu].counter = counter;
385 			mmap_array[nr_cpu].prev = 0;
386 			mmap_array[nr_cpu].mask = mmap_pages*page_size - 1;
387 			mmap_array[nr_cpu].base = mmap(NULL, (mmap_pages+1)*page_size,
388 				PROT_READ|PROT_WRITE, MAP_SHARED, fd[nr_cpu][counter][thread_index], 0);
389 			if (mmap_array[nr_cpu].base == MAP_FAILED) {
390 				error("failed to mmap with %d (%s)\n", errno, strerror(errno));
391 				exit(-1);
392 			}
393 
394 			event_array[nr_poll].fd = fd[nr_cpu][counter][thread_index];
395 			event_array[nr_poll].events = POLLIN;
396 			nr_poll++;
397 		}
398 
399 		if (filter != NULL) {
400 			ret = ioctl(fd[nr_cpu][counter][thread_index],
401 					PERF_EVENT_IOC_SET_FILTER, filter);
402 			if (ret) {
403 				error("failed to set filter with %d (%s)\n", errno,
404 						strerror(errno));
405 				exit(-1);
406 			}
407 		}
408 	}
409 }
410 
411 static void open_counters(int cpu)
412 {
413 	int counter;
414 
415 	group_fd = -1;
416 	for (counter = 0; counter < nr_counters; counter++)
417 		create_counter(counter, cpu);
418 
419 	nr_cpu++;
420 }
421 
422 static int process_buildids(void)
423 {
424 	u64 size = lseek(output, 0, SEEK_CUR);
425 
426 	if (size == 0)
427 		return 0;
428 
429 	session->fd = output;
430 	return __perf_session__process_events(session, post_processing_offset,
431 					      size - post_processing_offset,
432 					      size, &build_id__mark_dso_hit_ops);
433 }
434 
435 static void atexit_header(void)
436 {
437 	if (!pipe_output) {
438 		session->header.data_size += bytes_written;
439 
440 		process_buildids();
441 		perf_header__write(&session->header, output, true);
442 		perf_session__delete(session);
443 		symbol__exit();
444 	}
445 }
446 
447 static void event__synthesize_guest_os(struct machine *machine, void *data)
448 {
449 	int err;
450 	struct perf_session *psession = data;
451 
452 	if (machine__is_host(machine))
453 		return;
454 
455 	/*
456 	 *As for guest kernel when processing subcommand record&report,
457 	 *we arrange module mmap prior to guest kernel mmap and trigger
458 	 *a preload dso because default guest module symbols are loaded
459 	 *from guest kallsyms instead of /lib/modules/XXX/XXX. This
460 	 *method is used to avoid symbol missing when the first addr is
461 	 *in module instead of in guest kernel.
462 	 */
463 	err = event__synthesize_modules(process_synthesized_event,
464 					psession, machine);
465 	if (err < 0)
466 		pr_err("Couldn't record guest kernel [%d]'s reference"
467 		       " relocation symbol.\n", machine->pid);
468 
469 	/*
470 	 * We use _stext for guest kernel because guest kernel's /proc/kallsyms
471 	 * have no _text sometimes.
472 	 */
473 	err = event__synthesize_kernel_mmap(process_synthesized_event,
474 					    psession, machine, "_text");
475 	if (err < 0)
476 		err = event__synthesize_kernel_mmap(process_synthesized_event,
477 						    psession, machine, "_stext");
478 	if (err < 0)
479 		pr_err("Couldn't record guest kernel [%d]'s reference"
480 		       " relocation symbol.\n", machine->pid);
481 }
482 
483 static struct perf_event_header finished_round_event = {
484 	.size = sizeof(struct perf_event_header),
485 	.type = PERF_RECORD_FINISHED_ROUND,
486 };
487 
488 static void mmap_read_all(void)
489 {
490 	int i;
491 
492 	for (i = 0; i < nr_cpu; i++) {
493 		if (mmap_array[i].base)
494 			mmap_read(&mmap_array[i]);
495 	}
496 
497 	if (perf_header__has_feat(&session->header, HEADER_TRACE_INFO))
498 		write_output(&finished_round_event, sizeof(finished_round_event));
499 }
500 
501 static int __cmd_record(int argc, const char **argv)
502 {
503 	int i, counter;
504 	struct stat st;
505 	int flags;
506 	int err;
507 	unsigned long waking = 0;
508 	int child_ready_pipe[2], go_pipe[2];
509 	const bool forks = argc > 0;
510 	char buf;
511 	struct machine *machine;
512 
513 	page_size = sysconf(_SC_PAGE_SIZE);
514 
515 	atexit(sig_atexit);
516 	signal(SIGCHLD, sig_handler);
517 	signal(SIGINT, sig_handler);
518 
519 	if (forks && (pipe(child_ready_pipe) < 0 || pipe(go_pipe) < 0)) {
520 		perror("failed to create pipes");
521 		exit(-1);
522 	}
523 
524 	if (!strcmp(output_name, "-"))
525 		pipe_output = 1;
526 	else if (!stat(output_name, &st) && st.st_size) {
527 		if (write_mode == WRITE_FORCE) {
528 			char oldname[PATH_MAX];
529 			snprintf(oldname, sizeof(oldname), "%s.old",
530 				 output_name);
531 			unlink(oldname);
532 			rename(output_name, oldname);
533 		}
534 	} else if (write_mode == WRITE_APPEND) {
535 		write_mode = WRITE_FORCE;
536 	}
537 
538 	flags = O_CREAT|O_RDWR;
539 	if (write_mode == WRITE_APPEND)
540 		file_new = 0;
541 	else
542 		flags |= O_TRUNC;
543 
544 	if (pipe_output)
545 		output = STDOUT_FILENO;
546 	else
547 		output = open(output_name, flags, S_IRUSR | S_IWUSR);
548 	if (output < 0) {
549 		perror("failed to create output file");
550 		exit(-1);
551 	}
552 
553 	session = perf_session__new(output_name, O_WRONLY,
554 				    write_mode == WRITE_FORCE, false);
555 	if (session == NULL) {
556 		pr_err("Not enough memory for reading perf file header\n");
557 		return -1;
558 	}
559 
560 	if (!file_new) {
561 		err = perf_header__read(session, output);
562 		if (err < 0)
563 			goto out_delete_session;
564 	}
565 
566 	if (have_tracepoints(attrs, nr_counters))
567 		perf_header__set_feat(&session->header, HEADER_TRACE_INFO);
568 
569 	/*
570  	 * perf_session__delete(session) will be called at atexit_header()
571 	 */
572 	atexit(atexit_header);
573 
574 	if (forks) {
575 		child_pid = fork();
576 		if (child_pid < 0) {
577 			perror("failed to fork");
578 			exit(-1);
579 		}
580 
581 		if (!child_pid) {
582 			if (pipe_output)
583 				dup2(2, 1);
584 			close(child_ready_pipe[0]);
585 			close(go_pipe[1]);
586 			fcntl(go_pipe[0], F_SETFD, FD_CLOEXEC);
587 
588 			/*
589 			 * Do a dummy execvp to get the PLT entry resolved,
590 			 * so we avoid the resolver overhead on the real
591 			 * execvp call.
592 			 */
593 			execvp("", (char **)argv);
594 
595 			/*
596 			 * Tell the parent we're ready to go
597 			 */
598 			close(child_ready_pipe[1]);
599 
600 			/*
601 			 * Wait until the parent tells us to go.
602 			 */
603 			if (read(go_pipe[0], &buf, 1) == -1)
604 				perror("unable to read pipe");
605 
606 			execvp(argv[0], (char **)argv);
607 
608 			perror(argv[0]);
609 			exit(-1);
610 		}
611 
612 		if (!system_wide && target_tid == -1 && target_pid == -1)
613 			all_tids[0] = child_pid;
614 
615 		close(child_ready_pipe[1]);
616 		close(go_pipe[0]);
617 		/*
618 		 * wait for child to settle
619 		 */
620 		if (read(child_ready_pipe[0], &buf, 1) == -1) {
621 			perror("unable to read pipe");
622 			exit(-1);
623 		}
624 		close(child_ready_pipe[0]);
625 	}
626 
627 	nr_cpus = read_cpu_map(cpu_list);
628 	if (nr_cpus < 1) {
629 		perror("failed to collect number of CPUs\n");
630 		return -1;
631 	}
632 
633 	if (!system_wide && no_inherit && !cpu_list) {
634 		open_counters(-1);
635 	} else {
636 		for (i = 0; i < nr_cpus; i++)
637 			open_counters(cpumap[i]);
638 	}
639 
640 	if (pipe_output) {
641 		err = perf_header__write_pipe(output);
642 		if (err < 0)
643 			return err;
644 	} else if (file_new) {
645 		err = perf_header__write(&session->header, output, false);
646 		if (err < 0)
647 			return err;
648 	}
649 
650 	post_processing_offset = lseek(output, 0, SEEK_CUR);
651 
652 	if (pipe_output) {
653 		err = event__synthesize_attrs(&session->header,
654 					      process_synthesized_event,
655 					      session);
656 		if (err < 0) {
657 			pr_err("Couldn't synthesize attrs.\n");
658 			return err;
659 		}
660 
661 		err = event__synthesize_event_types(process_synthesized_event,
662 						    session);
663 		if (err < 0) {
664 			pr_err("Couldn't synthesize event_types.\n");
665 			return err;
666 		}
667 
668 		if (have_tracepoints(attrs, nr_counters)) {
669 			/*
670 			 * FIXME err <= 0 here actually means that
671 			 * there were no tracepoints so its not really
672 			 * an error, just that we don't need to
673 			 * synthesize anything.  We really have to
674 			 * return this more properly and also
675 			 * propagate errors that now are calling die()
676 			 */
677 			err = event__synthesize_tracing_data(output, attrs,
678 							     nr_counters,
679 							     process_synthesized_event,
680 							     session);
681 			if (err <= 0) {
682 				pr_err("Couldn't record tracing data.\n");
683 				return err;
684 			}
685 			advance_output(err);
686 		}
687 	}
688 
689 	machine = perf_session__find_host_machine(session);
690 	if (!machine) {
691 		pr_err("Couldn't find native kernel information.\n");
692 		return -1;
693 	}
694 
695 	err = event__synthesize_kernel_mmap(process_synthesized_event,
696 					    session, machine, "_text");
697 	if (err < 0)
698 		err = event__synthesize_kernel_mmap(process_synthesized_event,
699 						    session, machine, "_stext");
700 	if (err < 0) {
701 		pr_err("Couldn't record kernel reference relocation symbol.\n");
702 		return err;
703 	}
704 
705 	err = event__synthesize_modules(process_synthesized_event,
706 					session, machine);
707 	if (err < 0) {
708 		pr_err("Couldn't record kernel reference relocation symbol.\n");
709 		return err;
710 	}
711 	if (perf_guest)
712 		perf_session__process_machines(session, event__synthesize_guest_os);
713 
714 	if (!system_wide)
715 		event__synthesize_thread(target_tid, process_synthesized_event,
716 					 session);
717 	else
718 		event__synthesize_threads(process_synthesized_event, session);
719 
720 	if (realtime_prio) {
721 		struct sched_param param;
722 
723 		param.sched_priority = realtime_prio;
724 		if (sched_setscheduler(0, SCHED_FIFO, &param)) {
725 			pr_err("Could not set realtime priority.\n");
726 			exit(-1);
727 		}
728 	}
729 
730 	/*
731 	 * Let the child rip
732 	 */
733 	if (forks)
734 		close(go_pipe[1]);
735 
736 	for (;;) {
737 		int hits = samples;
738 		int thread;
739 
740 		mmap_read_all();
741 
742 		if (hits == samples) {
743 			if (done)
744 				break;
745 			err = poll(event_array, nr_poll, -1);
746 			waking++;
747 		}
748 
749 		if (done) {
750 			for (i = 0; i < nr_cpu; i++) {
751 				for (counter = 0;
752 					counter < nr_counters;
753 					counter++) {
754 					for (thread = 0;
755 						thread < thread_num;
756 						thread++)
757 						ioctl(fd[i][counter][thread],
758 							PERF_EVENT_IOC_DISABLE);
759 				}
760 			}
761 		}
762 	}
763 
764 	fprintf(stderr, "[ perf record: Woken up %ld times to write data ]\n", waking);
765 
766 	/*
767 	 * Approximate RIP event size: 24 bytes.
768 	 */
769 	fprintf(stderr,
770 		"[ perf record: Captured and wrote %.3f MB %s (~%lld samples) ]\n",
771 		(double)bytes_written / 1024.0 / 1024.0,
772 		output_name,
773 		bytes_written / 24);
774 
775 	return 0;
776 
777 out_delete_session:
778 	perf_session__delete(session);
779 	return err;
780 }
781 
782 static const char * const record_usage[] = {
783 	"perf record [<options>] [<command>]",
784 	"perf record [<options>] -- <command> [<options>]",
785 	NULL
786 };
787 
788 static bool force, append_file;
789 
790 static const struct option options[] = {
791 	OPT_CALLBACK('e', "event", NULL, "event",
792 		     "event selector. use 'perf list' to list available events",
793 		     parse_events),
794 	OPT_CALLBACK(0, "filter", NULL, "filter",
795 		     "event filter", parse_filter),
796 	OPT_INTEGER('p', "pid", &target_pid,
797 		    "record events on existing process id"),
798 	OPT_INTEGER('t', "tid", &target_tid,
799 		    "record events on existing thread id"),
800 	OPT_INTEGER('r', "realtime", &realtime_prio,
801 		    "collect data with this RT SCHED_FIFO priority"),
802 	OPT_BOOLEAN('R', "raw-samples", &raw_samples,
803 		    "collect raw sample records from all opened counters"),
804 	OPT_BOOLEAN('a', "all-cpus", &system_wide,
805 			    "system-wide collection from all CPUs"),
806 	OPT_BOOLEAN('A', "append", &append_file,
807 			    "append to the output file to do incremental profiling"),
808 	OPT_STRING('C', "cpu", &cpu_list, "cpu",
809 		    "list of cpus to monitor"),
810 	OPT_BOOLEAN('f', "force", &force,
811 			"overwrite existing data file (deprecated)"),
812 	OPT_U64('c', "count", &user_interval, "event period to sample"),
813 	OPT_STRING('o', "output", &output_name, "file",
814 		    "output file name"),
815 	OPT_BOOLEAN('i', "no-inherit", &no_inherit,
816 		    "child tasks do not inherit counters"),
817 	OPT_UINTEGER('F', "freq", &user_freq, "profile at this frequency"),
818 	OPT_UINTEGER('m', "mmap-pages", &mmap_pages, "number of mmap data pages"),
819 	OPT_BOOLEAN('g', "call-graph", &call_graph,
820 		    "do call-graph (stack chain/backtrace) recording"),
821 	OPT_INCR('v', "verbose", &verbose,
822 		    "be more verbose (show counter open errors, etc)"),
823 	OPT_BOOLEAN('s', "stat", &inherit_stat,
824 		    "per thread counts"),
825 	OPT_BOOLEAN('d', "data", &sample_address,
826 		    "Sample addresses"),
827 	OPT_BOOLEAN('n', "no-samples", &no_samples,
828 		    "don't sample"),
829 	OPT_BOOLEAN('N', "no-buildid-cache", &no_buildid,
830 		    "do not update the buildid cache"),
831 	OPT_END()
832 };
833 
834 int cmd_record(int argc, const char **argv, const char *prefix __used)
835 {
836 	int i, j, err = -ENOMEM;
837 
838 	argc = parse_options(argc, argv, options, record_usage,
839 			    PARSE_OPT_STOP_AT_NON_OPTION);
840 	if (!argc && target_pid == -1 && target_tid == -1 &&
841 		!system_wide && !cpu_list)
842 		usage_with_options(record_usage, options);
843 
844 	if (force && append_file) {
845 		fprintf(stderr, "Can't overwrite and append at the same time."
846 				" You need to choose between -f and -A");
847 		usage_with_options(record_usage, options);
848 	} else if (append_file) {
849 		write_mode = WRITE_APPEND;
850 	} else {
851 		write_mode = WRITE_FORCE;
852 	}
853 
854 	symbol__init();
855 	if (no_buildid)
856 		disable_buildid_cache();
857 
858 	if (!nr_counters) {
859 		nr_counters	= 1;
860 		attrs[0].type	= PERF_TYPE_HARDWARE;
861 		attrs[0].config = PERF_COUNT_HW_CPU_CYCLES;
862 	}
863 
864 	if (target_pid != -1) {
865 		target_tid = target_pid;
866 		thread_num = find_all_tid(target_pid, &all_tids);
867 		if (thread_num <= 0) {
868 			fprintf(stderr, "Can't find all threads of pid %d\n",
869 					target_pid);
870 			usage_with_options(record_usage, options);
871 		}
872 	} else {
873 		all_tids=malloc(sizeof(pid_t));
874 		if (!all_tids)
875 			goto out_symbol_exit;
876 
877 		all_tids[0] = target_tid;
878 		thread_num = 1;
879 	}
880 
881 	for (i = 0; i < MAX_NR_CPUS; i++) {
882 		for (j = 0; j < MAX_COUNTERS; j++) {
883 			fd[i][j] = malloc(sizeof(int)*thread_num);
884 			if (!fd[i][j])
885 				goto out_free_fd;
886 		}
887 	}
888 	event_array = malloc(
889 		sizeof(struct pollfd)*MAX_NR_CPUS*MAX_COUNTERS*thread_num);
890 	if (!event_array)
891 		goto out_free_fd;
892 
893 	if (user_interval != ULLONG_MAX)
894 		default_interval = user_interval;
895 	if (user_freq != UINT_MAX)
896 		freq = user_freq;
897 
898 	/*
899 	 * User specified count overrides default frequency.
900 	 */
901 	if (default_interval)
902 		freq = 0;
903 	else if (freq) {
904 		default_interval = freq;
905 	} else {
906 		fprintf(stderr, "frequency and count are zero, aborting\n");
907 		err = -EINVAL;
908 		goto out_free_event_array;
909 	}
910 
911 	err = __cmd_record(argc, argv);
912 
913 out_free_event_array:
914 	free(event_array);
915 out_free_fd:
916 	for (i = 0; i < MAX_NR_CPUS; i++) {
917 		for (j = 0; j < MAX_COUNTERS; j++)
918 			free(fd[i][j]);
919 	}
920 	free(all_tids);
921 	all_tids = NULL;
922 out_symbol_exit:
923 	symbol__exit();
924 	return err;
925 }
926