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.
8 #define _FILE_OFFSET_BITS 64
14 #include "util/build-id.h"
15 #include "util/util.h"
16 #include "util/parse-options.h"
17 #include "util/parse-events.h"
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"
35 static int *fd[MAX_NR_CPUS][MAX_COUNTERS];
37 static u64 user_interval = ULLONG_MAX;
38 static u64 default_interval = 0;
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;
46 static int pipe_output = 0;
47 static const char *output_name = "perf.data";
49 static int realtime_prio = 0;
50 static bool raw_samples = false;
51 static bool system_wide = false;
52 static int profile_cpu = -1;
53 static pid_t target_pid = -1;
54 static pid_t target_tid = -1;
55 static pid_t *all_tids = NULL;
56 static int thread_num = 0;
57 static pid_t child_pid = -1;
58 static bool no_inherit = false;
59 static enum write_mode_t write_mode = WRITE_FORCE;
60 static bool call_graph = false;
61 static bool inherit_stat = false;
62 static bool no_samples = false;
63 static bool sample_address = false;
65 static long samples = 0;
66 static u64 bytes_written = 0;
68 static struct pollfd *event_array;
70 static int nr_poll = 0;
71 static int nr_cpu = 0;
73 static int file_new = 1;
74 static off_t post_processing_offset;
76 static struct perf_session *session;
85 static struct mmap_data mmap_array[MAX_NR_CPUS];
87 static unsigned long mmap_read_head(struct mmap_data *md)
89 struct perf_event_mmap_page *pc = md->base;
98 static void mmap_write_tail(struct mmap_data *md, unsigned long tail)
100 struct perf_event_mmap_page *pc = md->base;
103 * ensure all reads are done before we write the tail out.
106 pc->data_tail = tail;
109 static void advance_output(size_t size)
111 bytes_written += size;
114 static void write_output(void *buf, size_t size)
117 int ret = write(output, buf, size);
120 die("failed to write");
125 bytes_written += ret;
129 static int process_synthesized_event(event_t *event,
130 struct perf_session *self __used)
132 write_output(event, event->header.size);
136 static void mmap_read(struct mmap_data *md)
138 unsigned int head = mmap_read_head(md);
139 unsigned int old = md->prev;
140 unsigned char *data = md->base + page_size;
146 * If we're further behind than half the buffer, there's a chance
147 * the writer will bite our tail and mess up the samples under us.
149 * If we somehow ended up ahead of the head, we got messed up.
151 * In either case, truncate and restart at head.
155 fprintf(stderr, "WARNING: failed to keep up with mmap data\n");
157 * head points to a known good entry, start there.
167 if ((old & md->mask) + size != (head & md->mask)) {
168 buf = &data[old & md->mask];
169 size = md->mask + 1 - (old & md->mask);
172 write_output(buf, size);
175 buf = &data[old & md->mask];
179 write_output(buf, size);
182 mmap_write_tail(md, old);
185 static volatile int done = 0;
186 static volatile int signr = -1;
188 static void sig_handler(int sig)
194 static void sig_atexit(void)
197 kill(child_pid, SIGTERM);
202 signal(signr, SIG_DFL);
203 kill(getpid(), signr);
208 static struct perf_header_attr *get_header_attr(struct perf_event_attr *a, int nr)
210 struct perf_header_attr *h_attr;
212 if (nr < session->header.attrs) {
213 h_attr = session->header.attr[nr];
215 h_attr = perf_header_attr__new(a);
217 if (perf_header__add_attr(&session->header, h_attr) < 0) {
218 perf_header_attr__delete(h_attr);
226 static void create_counter(int counter, int cpu)
228 char *filter = filters[counter];
229 struct perf_event_attr *attr = attrs + counter;
230 struct perf_header_attr *h_attr;
231 int track = !counter; /* only the first counter needs these */
241 attr->read_format = PERF_FORMAT_TOTAL_TIME_ENABLED |
242 PERF_FORMAT_TOTAL_TIME_RUNNING |
245 attr->sample_type |= PERF_SAMPLE_IP | PERF_SAMPLE_TID;
248 attr->sample_type |= PERF_SAMPLE_ID;
251 * We default some events to a 1 default interval. But keep
252 * it a weak assumption overridable by the user.
254 if (!attr->sample_period || (user_freq != UINT_MAX &&
255 user_interval != ULLONG_MAX)) {
257 attr->sample_type |= PERF_SAMPLE_PERIOD;
259 attr->sample_freq = freq;
261 attr->sample_period = default_interval;
266 attr->sample_freq = 0;
269 attr->inherit_stat = 1;
272 attr->sample_type |= PERF_SAMPLE_ADDR;
275 attr->sample_type |= PERF_SAMPLE_CALLCHAIN;
278 attr->sample_type |= PERF_SAMPLE_TIME;
279 attr->sample_type |= PERF_SAMPLE_RAW;
280 attr->sample_type |= PERF_SAMPLE_CPU;
285 attr->inherit = !no_inherit;
286 if (target_pid == -1 && target_tid == -1 && !system_wide) {
288 attr->enable_on_exec = 1;
291 for (thread_index = 0; thread_index < thread_num; thread_index++) {
293 fd[nr_cpu][counter][thread_index] = sys_perf_event_open(attr,
294 all_tids[thread_index], cpu, group_fd, 0);
296 if (fd[nr_cpu][counter][thread_index] < 0) {
299 if (err == EPERM || err == EACCES)
300 die("Permission error - are you root?\n"
301 "\t Consider tweaking"
302 " /proc/sys/kernel/perf_event_paranoid.\n");
303 else if (err == ENODEV && profile_cpu != -1) {
304 die("No such device - did you specify"
305 " an out-of-range profile CPU?\n");
309 * If it's cycles then fall back to hrtimer
310 * based cpu-clock-tick sw counter, which
311 * is always available even if no PMU support:
313 if (attr->type == PERF_TYPE_HARDWARE
314 && attr->config == PERF_COUNT_HW_CPU_CYCLES) {
317 warning(" ... trying to fall back to cpu-clock-ticks\n");
318 attr->type = PERF_TYPE_SOFTWARE;
319 attr->config = PERF_COUNT_SW_CPU_CLOCK;
323 error("perfcounter syscall returned with %d (%s)\n",
324 fd[nr_cpu][counter][thread_index], strerror(err));
326 #if defined(__i386__) || defined(__x86_64__)
327 if (attr->type == PERF_TYPE_HARDWARE && err == EOPNOTSUPP)
328 die("No hardware sampling interrupt available."
329 " No APIC? If so then you can boot the kernel"
330 " with the \"lapic\" boot parameter to"
331 " force-enable it.\n");
334 die("No CONFIG_PERF_EVENTS=y kernel support configured?\n");
338 h_attr = get_header_attr(attr, counter);
343 if (memcmp(&h_attr->attr, attr, sizeof(*attr))) {
344 fprintf(stderr, "incompatible append\n");
349 if (read(fd[nr_cpu][counter][thread_index], &read_data, sizeof(read_data)) == -1) {
350 perror("Unable to read perf file descriptor\n");
354 if (perf_header_attr__add_id(h_attr, read_data.id) < 0) {
355 pr_warning("Not enough memory to add id\n");
359 assert(fd[nr_cpu][counter][thread_index] >= 0);
360 fcntl(fd[nr_cpu][counter][thread_index], F_SETFL, O_NONBLOCK);
363 * First counter acts as the group leader:
365 if (group && group_fd == -1)
366 group_fd = fd[nr_cpu][counter][thread_index];
368 if (counter || thread_index) {
369 ret = ioctl(fd[nr_cpu][counter][thread_index],
370 PERF_EVENT_IOC_SET_OUTPUT,
373 error("failed to set output: %d (%s)\n", errno,
378 mmap_array[nr_cpu].counter = counter;
379 mmap_array[nr_cpu].prev = 0;
380 mmap_array[nr_cpu].mask = mmap_pages*page_size - 1;
381 mmap_array[nr_cpu].base = mmap(NULL, (mmap_pages+1)*page_size,
382 PROT_READ|PROT_WRITE, MAP_SHARED, fd[nr_cpu][counter][thread_index], 0);
383 if (mmap_array[nr_cpu].base == MAP_FAILED) {
384 error("failed to mmap with %d (%s)\n", errno, strerror(errno));
388 event_array[nr_poll].fd = fd[nr_cpu][counter][thread_index];
389 event_array[nr_poll].events = POLLIN;
393 if (filter != NULL) {
394 ret = ioctl(fd[nr_cpu][counter][thread_index],
395 PERF_EVENT_IOC_SET_FILTER, filter);
397 error("failed to set filter with %d (%s)\n", errno,
405 static void open_counters(int cpu)
410 for (counter = 0; counter < nr_counters; counter++)
411 create_counter(counter, cpu);
416 static int process_buildids(void)
418 u64 size = lseek(output, 0, SEEK_CUR);
423 session->fd = output;
424 return __perf_session__process_events(session, post_processing_offset,
425 size - post_processing_offset,
426 size, &build_id__mark_dso_hit_ops);
429 static void atexit_header(void)
432 session->header.data_size += bytes_written;
435 perf_header__write(&session->header, output, true);
439 static void event__synthesize_guest_os(struct machine *machine, void *data)
442 char *guest_kallsyms;
444 struct perf_session *psession = data;
446 if (machine__is_host(machine))
450 *As for guest kernel when processing subcommand record&report,
451 *we arrange module mmap prior to guest kernel mmap and trigger
452 *a preload dso because default guest module symbols are loaded
453 *from guest kallsyms instead of /lib/modules/XXX/XXX. This
454 *method is used to avoid symbol missing when the first addr is
455 *in module instead of in guest kernel.
457 err = event__synthesize_modules(process_synthesized_event,
460 pr_err("Couldn't record guest kernel [%d]'s reference"
461 " relocation symbol.\n", machine->pid);
463 if (machine__is_default_guest(machine))
464 guest_kallsyms = (char *) symbol_conf.default_guest_kallsyms;
466 sprintf(path, "%s/proc/kallsyms", machine->root_dir);
467 guest_kallsyms = path;
471 * We use _stext for guest kernel because guest kernel's /proc/kallsyms
472 * have no _text sometimes.
474 err = event__synthesize_kernel_mmap(process_synthesized_event,
475 psession, machine, "_text");
477 err = event__synthesize_kernel_mmap(process_synthesized_event,
478 psession, machine, "_stext");
480 pr_err("Couldn't record guest kernel [%d]'s reference"
481 " relocation symbol.\n", machine->pid);
484 static struct perf_event_header finished_round_event = {
485 .size = sizeof(struct perf_event_header),
486 .type = PERF_RECORD_FINISHED_ROUND,
489 static void mmap_read_all(void)
493 for (i = 0; i < nr_cpu; i++) {
494 if (mmap_array[i].base)
495 mmap_read(&mmap_array[i]);
498 if (perf_header__has_feat(&session->header, HEADER_TRACE_INFO))
499 write_output(&finished_round_event, sizeof(finished_round_event));
502 static int __cmd_record(int argc, const char **argv)
508 unsigned long waking = 0;
509 int child_ready_pipe[2], go_pipe[2];
510 const bool forks = argc > 0;
512 struct machine *machine;
514 page_size = sysconf(_SC_PAGE_SIZE);
517 signal(SIGCHLD, sig_handler);
518 signal(SIGINT, sig_handler);
520 if (forks && (pipe(child_ready_pipe) < 0 || pipe(go_pipe) < 0)) {
521 perror("failed to create pipes");
525 if (!strcmp(output_name, "-"))
527 else if (!stat(output_name, &st) && st.st_size) {
528 if (write_mode == WRITE_FORCE) {
529 char oldname[PATH_MAX];
530 snprintf(oldname, sizeof(oldname), "%s.old",
533 rename(output_name, oldname);
535 } else if (write_mode == WRITE_APPEND) {
536 write_mode = WRITE_FORCE;
539 flags = O_CREAT|O_RDWR;
540 if (write_mode == WRITE_APPEND)
546 output = STDOUT_FILENO;
548 output = open(output_name, flags, S_IRUSR | S_IWUSR);
550 perror("failed to create output file");
554 session = perf_session__new(output_name, O_WRONLY,
555 write_mode == WRITE_FORCE, false);
556 if (session == NULL) {
557 pr_err("Not enough memory for reading perf file header\n");
562 err = perf_header__read(session, output);
567 if (have_tracepoints(attrs, nr_counters))
568 perf_header__set_feat(&session->header, HEADER_TRACE_INFO);
570 atexit(atexit_header);
575 perror("failed to fork");
582 close(child_ready_pipe[0]);
584 fcntl(go_pipe[0], F_SETFD, FD_CLOEXEC);
587 * Do a dummy execvp to get the PLT entry resolved,
588 * so we avoid the resolver overhead on the real
591 execvp("", (char **)argv);
594 * Tell the parent we're ready to go
596 close(child_ready_pipe[1]);
599 * Wait until the parent tells us to go.
601 if (read(go_pipe[0], &buf, 1) == -1)
602 perror("unable to read pipe");
604 execvp(argv[0], (char **)argv);
610 if (!system_wide && target_tid == -1 && target_pid == -1)
611 all_tids[0] = child_pid;
613 close(child_ready_pipe[1]);
616 * wait for child to settle
618 if (read(child_ready_pipe[0], &buf, 1) == -1) {
619 perror("unable to read pipe");
622 close(child_ready_pipe[0]);
625 if ((!system_wide && no_inherit) || profile_cpu != -1) {
626 open_counters(profile_cpu);
628 nr_cpus = read_cpu_map();
629 for (i = 0; i < nr_cpus; i++)
630 open_counters(cpumap[i]);
634 err = perf_header__write_pipe(output);
637 } else if (file_new) {
638 err = perf_header__write(&session->header, output, false);
643 post_processing_offset = lseek(output, 0, SEEK_CUR);
646 err = event__synthesize_attrs(&session->header,
647 process_synthesized_event,
650 pr_err("Couldn't synthesize attrs.\n");
654 err = event__synthesize_event_types(process_synthesized_event,
657 pr_err("Couldn't synthesize event_types.\n");
661 if (have_tracepoints(attrs, nr_counters)) {
663 * FIXME err <= 0 here actually means that
664 * there were no tracepoints so its not really
665 * an error, just that we don't need to
666 * synthesize anything. We really have to
667 * return this more properly and also
668 * propagate errors that now are calling die()
670 err = event__synthesize_tracing_data(output, attrs,
672 process_synthesized_event,
675 pr_err("Couldn't record tracing data.\n");
682 machine = perf_session__find_host_machine(session);
684 pr_err("Couldn't find native kernel information.\n");
688 err = event__synthesize_kernel_mmap(process_synthesized_event,
689 session, machine, "_text");
691 err = event__synthesize_kernel_mmap(process_synthesized_event,
692 session, machine, "_stext");
694 pr_err("Couldn't record kernel reference relocation symbol.\n");
698 err = event__synthesize_modules(process_synthesized_event,
701 pr_err("Couldn't record kernel reference relocation symbol.\n");
705 perf_session__process_machines(session, event__synthesize_guest_os);
707 if (!system_wide && profile_cpu == -1)
708 event__synthesize_thread(target_tid, process_synthesized_event,
711 event__synthesize_threads(process_synthesized_event, session);
714 struct sched_param param;
716 param.sched_priority = realtime_prio;
717 if (sched_setscheduler(0, SCHED_FIFO, ¶m)) {
718 pr_err("Could not set realtime priority.\n");
735 if (hits == samples) {
738 err = poll(event_array, nr_poll, -1);
743 for (i = 0; i < nr_cpu; i++) {
745 counter < nr_counters;
750 ioctl(fd[i][counter][thread],
751 PERF_EVENT_IOC_DISABLE);
757 fprintf(stderr, "[ perf record: Woken up %ld times to write data ]\n", waking);
760 * Approximate RIP event size: 24 bytes.
763 "[ perf record: Captured and wrote %.3f MB %s (~%lld samples) ]\n",
764 (double)bytes_written / 1024.0 / 1024.0,
771 static const char * const record_usage[] = {
772 "perf record [<options>] [<command>]",
773 "perf record [<options>] -- <command> [<options>]",
777 static bool force, append_file;
779 static const struct option options[] = {
780 OPT_CALLBACK('e', "event", NULL, "event",
781 "event selector. use 'perf list' to list available events",
783 OPT_CALLBACK(0, "filter", NULL, "filter",
784 "event filter", parse_filter),
785 OPT_INTEGER('p', "pid", &target_pid,
786 "record events on existing process id"),
787 OPT_INTEGER('t', "tid", &target_tid,
788 "record events on existing thread id"),
789 OPT_INTEGER('r', "realtime", &realtime_prio,
790 "collect data with this RT SCHED_FIFO priority"),
791 OPT_BOOLEAN('R', "raw-samples", &raw_samples,
792 "collect raw sample records from all opened counters"),
793 OPT_BOOLEAN('a', "all-cpus", &system_wide,
794 "system-wide collection from all CPUs"),
795 OPT_BOOLEAN('A', "append", &append_file,
796 "append to the output file to do incremental profiling"),
797 OPT_INTEGER('C', "profile_cpu", &profile_cpu,
798 "CPU to profile on"),
799 OPT_BOOLEAN('f', "force", &force,
800 "overwrite existing data file (deprecated)"),
801 OPT_U64('c', "count", &user_interval, "event period to sample"),
802 OPT_STRING('o', "output", &output_name, "file",
804 OPT_BOOLEAN('i', "no-inherit", &no_inherit,
805 "child tasks do not inherit counters"),
806 OPT_UINTEGER('F', "freq", &user_freq, "profile at this frequency"),
807 OPT_UINTEGER('m', "mmap-pages", &mmap_pages, "number of mmap data pages"),
808 OPT_BOOLEAN('g', "call-graph", &call_graph,
809 "do call-graph (stack chain/backtrace) recording"),
810 OPT_INCR('v', "verbose", &verbose,
811 "be more verbose (show counter open errors, etc)"),
812 OPT_BOOLEAN('s', "stat", &inherit_stat,
813 "per thread counts"),
814 OPT_BOOLEAN('d', "data", &sample_address,
816 OPT_BOOLEAN('n', "no-samples", &no_samples,
821 int cmd_record(int argc, const char **argv, const char *prefix __used)
825 argc = parse_options(argc, argv, options, record_usage,
826 PARSE_OPT_STOP_AT_NON_OPTION);
827 if (!argc && target_pid == -1 && target_tid == -1 &&
828 !system_wide && profile_cpu == -1)
829 usage_with_options(record_usage, options);
831 if (force && append_file) {
832 fprintf(stderr, "Can't overwrite and append at the same time."
833 " You need to choose between -f and -A");
834 usage_with_options(record_usage, options);
835 } else if (append_file) {
836 write_mode = WRITE_APPEND;
838 write_mode = WRITE_FORCE;
845 attrs[0].type = PERF_TYPE_HARDWARE;
846 attrs[0].config = PERF_COUNT_HW_CPU_CYCLES;
849 if (target_pid != -1) {
850 target_tid = target_pid;
851 thread_num = find_all_tid(target_pid, &all_tids);
852 if (thread_num <= 0) {
853 fprintf(stderr, "Can't find all threads of pid %d\n",
855 usage_with_options(record_usage, options);
858 all_tids=malloc(sizeof(pid_t));
862 all_tids[0] = target_tid;
866 for (i = 0; i < MAX_NR_CPUS; i++) {
867 for (j = 0; j < MAX_COUNTERS; j++) {
868 fd[i][j] = malloc(sizeof(int)*thread_num);
873 event_array = malloc(
874 sizeof(struct pollfd)*MAX_NR_CPUS*MAX_COUNTERS*thread_num);
878 if (user_interval != ULLONG_MAX)
879 default_interval = user_interval;
880 if (user_freq != UINT_MAX)
884 * User specified count overrides default frequency.
886 if (default_interval)
889 default_interval = freq;
891 fprintf(stderr, "frequency and count are zero, aborting\n");
895 return __cmd_record(argc, argv);