tools/perf/builtin-record.c

   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 #include "builtin.h"
   9
  10 #include "perf.h"
  11
  12 #include "util/util.h"
  13 #include "util/parse-options.h"
  14 #include "util/parse-events.h"
  15 #include "util/string.h"
  16
  17 #include "util/header.h"
  18 #include "util/event.h"
  19 #include "util/debug.h"
  20 #include "util/trace-event.h"
  21
  22 #include <unistd.h>
  23 #include <sched.h>
  24
  25 #define ALIGN(x, a)             __ALIGN_MASK(x, (typeof(x))(a)-1)
  26 #define __ALIGN_MASK(x, mask)   (((x)+(mask))&~(mask))
  27
  28 static int                      fd[MAX_NR_CPUS][MAX_COUNTERS];
  29
  30 static long                     default_interval                = 100000;
  31
  32 static int                      nr_cpus                         = 0;
  33 static unsigned int             page_size;
  34 static unsigned int             mmap_pages                      = 128;
  35 static int                      freq                            = 0;
  36 static int                      output;
  37 static const char               *output_name                    = "perf.data";
  38 static int                      group                           = 0;
  39 static unsigned int             realtime_prio                   = 0;
  40 static int                      raw_samples                     = 0;
  41 static int                      system_wide                     = 0;
  42 static int                      profile_cpu                     = -1;
  43 static pid_t                    target_pid                      = -1;
  44 static int                      inherit                         = 1;
  45 static int                      force                           = 0;
  46 static int                      append_file                     = 0;
  47 static int                      call_graph                      = 0;
  48 static int                      inherit_stat                    = 0;
  49 static int                      no_samples                      = 0;
  50 static int                      sample_address                  = 0;
  51 static int                      multiplex                       = 0;
  52 static int                      multiplex_fd                    = -1;
  53
  54 static long                     samples;
  55 static struct timeval           last_read;
  56 static struct timeval           this_read;
  57
  58 static u64                      bytes_written;
  59
  60 static struct pollfd            event_array[MAX_NR_CPUS * MAX_COUNTERS];
  61
  62 static int                      nr_poll;
  63 static int                      nr_cpu;
  64
  65 static int                      file_new = 1;
  66
  67 struct perf_header              *header;
  68
  69 struct mmap_data {
  70         int                     counter;
  71         void                    *base;
  72         unsigned int            mask;
  73         unsigned int            prev;
  74 };
  75
  76 static struct mmap_data         mmap_array[MAX_NR_CPUS][MAX_COUNTERS];
  77
  78 static unsigned long mmap_read_head(struct mmap_data *md)
  79 {
  80         struct perf_event_mmap_page *pc = md->base;
  81         long head;
  82
  83         head = pc->data_head;
  84         rmb();
  85
  86         return head;
  87 }
  88
  89 static void mmap_write_tail(struct mmap_data *md, unsigned long tail)
  90 {
  91         struct perf_event_mmap_page *pc = md->base;
  92
  93         /*
  94          * ensure all reads are done before we write the tail out.
  95          */
  96         /* mb(); */
  97         pc->data_tail = tail;
  98 }
  99
 100 static void write_output(void *buf, size_t size)
 101 {
 102         while (size) {
 103                 int ret = write(output, buf, size);
 104
 105                 if (ret < 0)
 106                         die("failed to write");
 107
 108                 size -= ret;
 109                 buf += ret;
 110
 111                 bytes_written += ret;
 112         }
 113 }
 114
 115 static void mmap_read(struct mmap_data *md)
 116 {
 117         unsigned int head = mmap_read_head(md);
 118         unsigned int old = md->prev;
 119         unsigned char *data = md->base + page_size;
 120         unsigned long size;
 121         void *buf;
 122         int diff;
 123
 124         gettimeofday(&this_read, NULL);
 125
 126         /*
 127          * If we're further behind than half the buffer, there's a chance
 128          * the writer will bite our tail and mess up the samples under us.
 129          *
 130          * If we somehow ended up ahead of the head, we got messed up.
 131          *
 132          * In either case, truncate and restart at head.
 133          */
 134         diff = head - old;
 135         if (diff < 0) {
 136                 struct timeval iv;
 137                 unsigned long msecs;
 138
 139                 timersub(&this_read, &last_read, &iv);
 140                 msecs = iv.tv_sec*1000 + iv.tv_usec/1000;
 141
 142                 fprintf(stderr, "WARNING: failed to keep up with mmap data."
 143                                 "  Last read %lu msecs ago.\n", msecs);
 144
 145                 /*
 146                  * head points to a known good entry, start there.
 147                  */
 148                 old = head;
 149         }
 150
 151         last_read = this_read;
 152
 153         if (old != head)
 154                 samples++;
 155
 156         size = head - old;
 157
 158         if ((old & md->mask) + size != (head & md->mask)) {
 159                 buf = &data[old & md->mask];
 160                 size = md->mask + 1 - (old & md->mask);
 161                 old += size;
 162
 163                 write_output(buf, size);
 164         }
 165
 166         buf = &data[old & md->mask];
 167         size = head - old;
 168         old += size;
 169
 170         write_output(buf, size);
 171
 172         md->prev = old;
 173         mmap_write_tail(md, old);
 174 }
 175
 176 static volatile int done = 0;
 177 static volatile int signr = -1;
 178
 179 static void sig_handler(int sig)
 180 {
 181         done = 1;
 182         signr = sig;
 183 }
 184
 185 static void sig_atexit(void)
 186 {
 187         if (signr == -1)
 188                 return;
 189
 190         signal(signr, SIG_DFL);
 191         kill(getpid(), signr);
 192 }
 193
 194 static pid_t pid_synthesize_comm_event(pid_t pid, int full)
 195 {
 196         struct comm_event comm_ev;
 197         char filename[PATH_MAX];
 198         char bf[BUFSIZ];
 199         FILE *fp;
 200         size_t size = 0;
 201         DIR *tasks;
 202         struct dirent dirent, *next;
 203         pid_t tgid = 0;
 204
 205         snprintf(filename, sizeof(filename), "/proc/%d/status", pid);
 206
 207         fp = fopen(filename, "r");
 208         if (fp == NULL) {
 209                 /*
 210                  * We raced with a task exiting - just return:
 211                  */
 212                 if (verbose)
 213                         fprintf(stderr, "couldn't open %s\n", filename);
 214                 return 0;
 215         }
 216
 217         memset(&comm_ev, 0, sizeof(comm_ev));
 218         while (!comm_ev.comm[0] || !comm_ev.pid) {
 219                 if (fgets(bf, sizeof(bf), fp) == NULL)
 220                         goto out_failure;
 221
 222                 if (memcmp(bf, "Name:", 5) == 0) {
 223                         char *name = bf + 5;
 224                         while (*name && isspace(*name))
 225                                 ++name;
 226                         size = strlen(name) - 1;
 227                         memcpy(comm_ev.comm, name, size++);
 228                 } else if (memcmp(bf, "Tgid:", 5) == 0) {
 229                         char *tgids = bf + 5;
 230                         while (*tgids && isspace(*tgids))
 231                                 ++tgids;
 232                         tgid = comm_ev.pid = atoi(tgids);
 233                 }
 234         }
 235
 236         comm_ev.header.type = PERF_RECORD_COMM;
 237         size = ALIGN(size, sizeof(u64));
 238         comm_ev.header.size = sizeof(comm_ev) - (sizeof(comm_ev.comm) - size);
 239
 240         if (!full) {
 241                 comm_ev.tid = pid;
 242
 243                 write_output(&comm_ev, comm_ev.header.size);
 244                 goto out_fclose;
 245         }
 246
 247         snprintf(filename, sizeof(filename), "/proc/%d/task", pid);
 248
 249         tasks = opendir(filename);
 250         while (!readdir_r(tasks, &dirent, &next) && next) {
 251                 char *end;
 252                 pid = strtol(dirent.d_name, &end, 10);
 253                 if (*end)
 254                         continue;
 255
 256                 comm_ev.tid = pid;
 257
 258                 write_output(&comm_ev, comm_ev.header.size);
 259         }
 260         closedir(tasks);
 261
 262 out_fclose:
 263         fclose(fp);
 264         return tgid;
 265
 266 out_failure:
 267         fprintf(stderr, "couldn't get COMM and pgid, malformed %s\n",
 268                 filename);
 269         exit(EXIT_FAILURE);
 270 }
 271
 272 static void pid_synthesize_mmap_samples(pid_t pid, pid_t tgid)
 273 {
 274         char filename[PATH_MAX];
 275         FILE *fp;
 276
 277         snprintf(filename, sizeof(filename), "/proc/%d/maps", pid);
 278
 279         fp = fopen(filename, "r");
 280         if (fp == NULL) {
 281                 /*
 282                  * We raced with a task exiting - just return:
 283                  */
 284                 if (verbose)
 285                         fprintf(stderr, "couldn't open %s\n", filename);
 286                 return;
 287         }
 288         while (1) {
 289                 char bf[BUFSIZ], *pbf = bf;
 290                 struct mmap_event mmap_ev = {
 291                         .header = { .type = PERF_RECORD_MMAP },
 292                 };
 293                 int n;
 294                 size_t size;
 295                 if (fgets(bf, sizeof(bf), fp) == NULL)
 296                         break;
 297
 298                 /* 00400000-0040c000 r-xp 00000000 fd:01 41038  /bin/cat */
 299                 n = hex2u64(pbf, &mmap_ev.start);
 300                 if (n < 0)
 301                         continue;
 302                 pbf += n + 1;
 303                 n = hex2u64(pbf, &mmap_ev.len);
 304                 if (n < 0)
 305                         continue;
 306                 pbf += n + 3;
 307                 if (*pbf == 'x') { /* vm_exec */
 308                         char *execname = strchr(bf, '/');
 309
 310                         /* Catch VDSO */
 311                         if (execname == NULL)
 312                                 execname = strstr(bf, "[vdso]");
 313
 314                         if (execname == NULL)
 315                                 continue;
 316
 317                         size = strlen(execname);
 318                         execname[size - 1] = '\0'; /* Remove \n */
 319                         memcpy(mmap_ev.filename, execname, size);
 320                         size = ALIGN(size, sizeof(u64));
 321                         mmap_ev.len -= mmap_ev.start;
 322                         mmap_ev.header.size = (sizeof(mmap_ev) -
 323                                                (sizeof(mmap_ev.filename) - size));
 324                         mmap_ev.pid = tgid;
 325                         mmap_ev.tid = pid;
 326
 327                         write_output(&mmap_ev, mmap_ev.header.size);
 328                 }
 329         }
 330
 331         fclose(fp);
 332 }
 333
 334 static void synthesize_all(void)
 335 {
 336         DIR *proc;
 337         struct dirent dirent, *next;
 338
 339         proc = opendir("/proc");
 340
 341         while (!readdir_r(proc, &dirent, &next) && next) {
 342                 char *end;
 343                 pid_t pid, tgid;
 344
 345                 pid = strtol(dirent.d_name, &end, 10);
 346                 if (*end) /* only interested in proper numerical dirents */
 347                         continue;
 348
 349                 tgid = pid_synthesize_comm_event(pid, 1);
 350                 pid_synthesize_mmap_samples(pid, tgid);
 351         }
 352
 353         closedir(proc);
 354 }
 355
 356 static int group_fd;
 357
 358 static struct perf_header_attr *get_header_attr(struct perf_event_attr *a, int nr)
 359 {
 360         struct perf_header_attr *h_attr;
 361
 362         if (nr < header->attrs) {
 363                 h_attr = header->attr[nr];
 364         } else {
 365                 h_attr = perf_header_attr__new(a);
 366                 perf_header__add_attr(header, h_attr);
 367         }
 368
 369         return h_attr;
 370 }
 371
 372 static void create_counter(int counter, int cpu, pid_t pid)
 373 {
 374         struct perf_event_attr *attr = attrs + counter;
 375         struct perf_header_attr *h_attr;
 376         int track = !counter; /* only the first counter needs these */
 377         struct {
 378                 u64 count;
 379                 u64 time_enabled;
 380                 u64 time_running;
 381                 u64 id;
 382         } read_data;
 383
 384         attr->read_format       = PERF_FORMAT_TOTAL_TIME_ENABLED |
 385                                   PERF_FORMAT_TOTAL_TIME_RUNNING |
 386                                   PERF_FORMAT_ID;
 387
 388         attr->sample_type       |= PERF_SAMPLE_IP | PERF_SAMPLE_TID;
 389
 390         if (freq) {
 391                 attr->sample_type       |= PERF_SAMPLE_PERIOD;
 392                 attr->freq              = 1;
 393                 attr->sample_freq       = freq;
 394         }
 395
 396         if (no_samples)
 397                 attr->sample_freq = 0;
 398
 399         if (inherit_stat)
 400                 attr->inherit_stat = 1;
 401
 402         if (sample_address)
 403                 attr->sample_type       |= PERF_SAMPLE_ADDR;
 404
 405         if (call_graph)
 406                 attr->sample_type       |= PERF_SAMPLE_CALLCHAIN;
 407
 408         if (raw_samples) {
 409                 attr->sample_type       |= PERF_SAMPLE_TIME;
 410                 attr->sample_type       |= PERF_SAMPLE_RAW;
 411                 attr->sample_type       |= PERF_SAMPLE_CPU;
 412         }
 413
 414         attr->mmap              = track;
 415         attr->comm              = track;
 416         attr->inherit           = (cpu < 0) && inherit;
 417         attr->disabled          = 1;
 418
 419 try_again:
 420         fd[nr_cpu][counter] = sys_perf_event_open(attr, pid, cpu, group_fd, 0);
 421
 422         if (fd[nr_cpu][counter] < 0) {
 423                 int err = errno;
 424
 425                 if (err == EPERM)
 426                         die("Permission error - are you root?\n");
 427                 else if (err ==  ENODEV && profile_cpu != -1)
 428                         die("No such device - did you specify an out-of-range profile CPU?\n");
 429
 430                 /*
 431                  * If it's cycles then fall back to hrtimer
 432                  * based cpu-clock-tick sw counter, which
 433                  * is always available even if no PMU support:
 434                  */
 435                 if (attr->type == PERF_TYPE_HARDWARE
 436                         && attr->config == PERF_COUNT_HW_CPU_CYCLES) {
 437
 438                         if (verbose)
 439                                 warning(" ... trying to fall back to cpu-clock-ticks\n");
 440                         attr->type = PERF_TYPE_SOFTWARE;
 441                         attr->config = PERF_COUNT_SW_CPU_CLOCK;
 442                         goto try_again;
 443                 }
 444                 printf("\n");
 445                 error("perfcounter syscall returned with %d (%s)\n",
 446                         fd[nr_cpu][counter], strerror(err));
 447                 die("No CONFIG_PERF_EVENTS=y kernel support configured?\n");
 448                 exit(-1);
 449         }
 450
 451         h_attr = get_header_attr(attr, counter);
 452
 453         if (!file_new) {
 454                 if (memcmp(&h_attr->attr, attr, sizeof(*attr))) {
 455                         fprintf(stderr, "incompatible append\n");
 456                         exit(-1);
 457                 }
 458         }
 459
 460         if (read(fd[nr_cpu][counter], &read_data, sizeof(read_data)) == -1) {
 461                 perror("Unable to read perf file descriptor\n");
 462                 exit(-1);
 463         }
 464
 465         perf_header_attr__add_id(h_attr, read_data.id);
 466
 467         assert(fd[nr_cpu][counter] >= 0);
 468         fcntl(fd[nr_cpu][counter], F_SETFL, O_NONBLOCK);
 469
 470         /*
 471          * First counter acts as the group leader:
 472          */
 473         if (group && group_fd == -1)
 474                 group_fd = fd[nr_cpu][counter];
 475         if (multiplex && multiplex_fd == -1)
 476                 multiplex_fd = fd[nr_cpu][counter];
 477
 478         if (multiplex && fd[nr_cpu][counter] != multiplex_fd) {
 479                 int ret;
 480
 481                 ret = ioctl(fd[nr_cpu][counter], PERF_EVENT_IOC_SET_OUTPUT, multiplex_fd);
 482                 assert(ret != -1);
 483         } else {
 484                 event_array[nr_poll].fd = fd[nr_cpu][counter];
 485                 event_array[nr_poll].events = POLLIN;
 486                 nr_poll++;
 487
 488                 mmap_array[nr_cpu][counter].counter = counter;
 489                 mmap_array[nr_cpu][counter].prev = 0;
 490                 mmap_array[nr_cpu][counter].mask = mmap_pages*page_size - 1;
 491                 mmap_array[nr_cpu][counter].base = mmap(NULL, (mmap_pages+1)*page_size,
 492                                 PROT_READ|PROT_WRITE, MAP_SHARED, fd[nr_cpu][counter], 0);
 493                 if (mmap_array[nr_cpu][counter].base == MAP_FAILED) {
 494                         error("failed to mmap with %d (%s)\n", errno, strerror(errno));
 495                         exit(-1);
 496                 }
 497         }
 498
 499         ioctl(fd[nr_cpu][counter], PERF_EVENT_IOC_ENABLE);
 500 }
 501
 502 static void open_counters(int cpu, pid_t pid)
 503 {
 504         int counter;
 505
 506         group_fd = -1;
 507         for (counter = 0; counter < nr_counters; counter++)
 508                 create_counter(counter, cpu, pid);
 509
 510         nr_cpu++;
 511 }
 512
 513 static void atexit_header(void)
 514 {
 515         header->data_size += bytes_written;
 516
 517         perf_header__write(header, output);
 518 }
 519
 520 static int __cmd_record(int argc, const char **argv)
 521 {
 522         int i, counter;
 523         struct stat st;
 524         pid_t pid = 0;
 525         int flags;
 526         int ret;
 527         unsigned long waking = 0;
 528
 529         page_size = sysconf(_SC_PAGE_SIZE);
 530         nr_cpus = sysconf(_SC_NPROCESSORS_ONLN);
 531         assert(nr_cpus <= MAX_NR_CPUS);
 532         assert(nr_cpus >= 0);
 533
 534         atexit(sig_atexit);
 535         signal(SIGCHLD, sig_handler);
 536         signal(SIGINT, sig_handler);
 537
 538         if (!stat(output_name, &st) && st.st_size) {
 539                 if (!force && !append_file) {
 540                         fprintf(stderr, "Error, output file %s exists, use -A to append or -f to overwrite.\n",
 541                                         output_name);
 542                         exit(-1);
 543                 }
 544         } else {
 545                 append_file = 0;
 546         }
 547
 548         flags = O_CREAT|O_RDWR;
 549         if (append_file)
 550                 file_new = 0;
 551         else
 552                 flags |= O_TRUNC;
 553
 554         output = open(output_name, flags, S_IRUSR|S_IWUSR);
 555         if (output < 0) {
 556                 perror("failed to create output file");
 557                 exit(-1);
 558         }
 559
 560         if (!file_new)
 561                 header = perf_header__read(output);
 562         else
 563                 header = perf_header__new();
 564
 565
 566         if (raw_samples) {
 567                 read_tracing_data(attrs, nr_counters);
 568         } else {
 569                 for (i = 0; i < nr_counters; i++) {
 570                         if (attrs[i].sample_type & PERF_SAMPLE_RAW) {
 571                                 read_tracing_data(attrs, nr_counters);
 572                                 break;
 573                         }
 574                 }
 575         }
 576         atexit(atexit_header);
 577
 578         if (!system_wide) {
 579                 pid = target_pid;
 580                 if (pid == -1)
 581                         pid = getpid();
 582
 583                 open_counters(profile_cpu, pid);
 584         } else {
 585                 if (profile_cpu != -1) {
 586                         open_counters(profile_cpu, target_pid);
 587                 } else {
 588                         for (i = 0; i < nr_cpus; i++)
 589                                 open_counters(i, target_pid);
 590                 }
 591         }
 592
 593         if (file_new)
 594                 perf_header__write(header, output);
 595
 596         if (!system_wide) {
 597                 pid_t tgid = pid_synthesize_comm_event(pid, 0);
 598                 pid_synthesize_mmap_samples(pid, tgid);
 599         } else
 600                 synthesize_all();
 601
 602         if (target_pid == -1 && argc) {
 603                 pid = fork();
 604                 if (pid < 0)
 605                         perror("failed to fork");
 606
 607                 if (!pid) {
 608                         if (execvp(argv[0], (char **)argv)) {
 609                                 perror(argv[0]);
 610                                 exit(-1);
 611                         }
 612                 }
 613         }
 614
 615         if (realtime_prio) {
 616                 struct sched_param param;
 617
 618                 param.sched_priority = realtime_prio;
 619                 if (sched_setscheduler(0, SCHED_FIFO, &param)) {
 620                         printf("Could not set realtime priority.\n");
 621                         exit(-1);
 622                 }
 623         }
 624
 625         for (;;) {
 626                 int hits = samples;
 627
 628                 for (i = 0; i < nr_cpu; i++) {
 629                         for (counter = 0; counter < nr_counters; counter++) {
 630                                 if (mmap_array[i][counter].base)
 631                                         mmap_read(&mmap_array[i][counter]);
 632                         }
 633                 }
 634
 635                 if (hits == samples) {
 636                         if (done)
 637                                 break;
 638                         ret = poll(event_array, nr_poll, -1);
 639                         waking++;
 640                 }
 641
 642                 if (done) {
 643                         for (i = 0; i < nr_cpu; i++) {
 644                                 for (counter = 0; counter < nr_counters; counter++)
 645                                         ioctl(fd[i][counter], PERF_EVENT_IOC_DISABLE);
 646                         }
 647                 }
 648         }
 649
 650         fprintf(stderr, "[ perf record: Woken up %ld times to write data ]\n", waking);
 651
 652         /*
 653          * Approximate RIP event size: 24 bytes.
 654          */
 655         fprintf(stderr,
 656                 "[ perf record: Captured and wrote %.3f MB %s (~%lld samples) ]\n",
 657                 (double)bytes_written / 1024.0 / 1024.0,
 658                 output_name,
 659                 bytes_written / 24);
 660
 661         return 0;
 662 }
 663
 664 static const char * const record_usage[] = {
 665         "perf record [<options>] [<command>]",
 666         "perf record [<options>] -- <command> [<options>]",
 667         NULL
 668 };
 669
 670 static const struct option options[] = {
 671         OPT_CALLBACK('e', "event", NULL, "event",
 672                      "event selector. use 'perf list' to list available events",
 673                      parse_events),
 674         OPT_INTEGER('p', "pid", &target_pid,
 675                     "record events on existing pid"),
 676         OPT_INTEGER('r', "realtime", &realtime_prio,
 677                     "collect data with this RT SCHED_FIFO priority"),
 678         OPT_BOOLEAN('R', "raw-samples", &raw_samples,
 679                     "collect raw sample records from all opened counters"),
 680         OPT_BOOLEAN('a', "all-cpus", &system_wide,
 681                             "system-wide collection from all CPUs"),
 682         OPT_BOOLEAN('A', "append", &append_file,
 683                             "append to the output file to do incremental profiling"),
 684         OPT_INTEGER('C', "profile_cpu", &profile_cpu,
 685                             "CPU to profile on"),
 686         OPT_BOOLEAN('f', "force", &force,
 687                         "overwrite existing data file"),
 688         OPT_LONG('c', "count", &default_interval,
 689                     "event period to sample"),
 690         OPT_STRING('o', "output", &output_name, "file",
 691                     "output file name"),
 692         OPT_BOOLEAN('i', "inherit", &inherit,
 693                     "child tasks inherit counters"),
 694         OPT_INTEGER('F', "freq", &freq,
 695                     "profile at this frequency"),
 696         OPT_INTEGER('m', "mmap-pages", &mmap_pages,
 697                     "number of mmap data pages"),
 698         OPT_BOOLEAN('g', "call-graph", &call_graph,
 699                     "do call-graph (stack chain/backtrace) recording"),
 700         OPT_BOOLEAN('v', "verbose", &verbose,
 701                     "be more verbose (show counter open errors, etc)"),
 702         OPT_BOOLEAN('s', "stat", &inherit_stat,
 703                     "per thread counts"),
 704         OPT_BOOLEAN('d', "data", &sample_address,
 705                     "Sample addresses"),
 706         OPT_BOOLEAN('n', "no-samples", &no_samples,
 707                     "don't sample"),
 708         OPT_BOOLEAN('M', "multiplex", &multiplex,
 709                     "multiplex counter output in a single channel"),
 710         OPT_END()
 711 };
 712
 713 int cmd_record(int argc, const char **argv, const char *prefix __used)
 714 {
 715         int counter;
 716
 717         argc = parse_options(argc, argv, options, record_usage,
 718                 PARSE_OPT_STOP_AT_NON_OPTION);
 719         if (!argc && target_pid == -1 && !system_wide)
 720                 usage_with_options(record_usage, options);
 721
 722         if (!nr_counters) {
 723                 nr_counters     = 1;
 724                 attrs[0].type   = PERF_TYPE_HARDWARE;
 725                 attrs[0].config = PERF_COUNT_HW_CPU_CYCLES;
 726         }
 727
 728         for (counter = 0; counter < nr_counters; counter++) {
 729                 if (attrs[counter].sample_period)
 730                         continue;
 731
 732                 attrs[counter].sample_period = default_interval;
 733         }
 734
 735         return __cmd_record(argc, argv);
 736 }