SAFE public projects git trees. - safe/jmp/linux-2.6/blob - 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
  21 #include <unistd.h>
  22 #include <sched.h>
  23
  24 #define ALIGN(x, a)             __ALIGN_MASK(x, (typeof(x))(a)-1)
  25 #define __ALIGN_MASK(x, mask)   (((x)+(mask))&~(mask))
  26
  27 static int                      fd[MAX_NR_CPUS][MAX_COUNTERS];
  28
  29 static long                     default_interval                =      0;
  30
  31 static int                      nr_cpus                         =      0;
  32 static unsigned int             page_size;
  33 static unsigned int             mmap_pages                      =    128;
  34 static int                      freq                            =   1000;
  35 static int                      output;
  36 static const char               *output_name                    = "perf.data";
  37 static int                      group                           =      0;
  38 static unsigned int             realtime_prio                   =      0;
  39 static int                      raw_samples                     =      0;
  40 static int                      system_wide                     =      0;
  41 static int                      profile_cpu                     =     -1;
  42 static pid_t                    target_pid                      =     -1;
  43 static pid_t                    child_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                         =      0;
  55 static struct timeval           last_read;
  56 static struct timeval           this_read;
  57
  58 static u64                      bytes_written                   =      0;
  59
  60 static struct pollfd            event_array[MAX_NR_CPUS * MAX_COUNTERS];
  61
  62 static int                      nr_poll                         =      0;
  63 static int                      nr_cpu                          =      0;
  64
  65 static int                      file_new                        =      1;
  66
  67 struct perf_header              *header                         =   NULL;
  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 (child_pid != -1)
 188                 kill(child_pid, SIGTERM);
 189
 190         if (signr == -1)
 191                 return;
 192
 193         signal(signr, SIG_DFL);
 194         kill(getpid(), signr);
 195 }
 196
 197 static pid_t pid_synthesize_comm_event(pid_t pid, int full)
 198 {
 199         struct comm_event comm_ev;
 200         char filename[PATH_MAX];
 201         char bf[BUFSIZ];
 202         FILE *fp;
 203         size_t size = 0;
 204         DIR *tasks;
 205         struct dirent dirent, *next;
 206         pid_t tgid = 0;
 207
 208         snprintf(filename, sizeof(filename), "/proc/%d/status", pid);
 209
 210         fp = fopen(filename, "r");
 211         if (fp == NULL) {
 212                 /*
 213                  * We raced with a task exiting - just return:
 214                  */
 215                 if (verbose)
 216                         fprintf(stderr, "couldn't open %s\n", filename);
 217                 return 0;
 218         }
 219
 220         memset(&comm_ev, 0, sizeof(comm_ev));
 221         while (!comm_ev.comm[0] || !comm_ev.pid) {
 222                 if (fgets(bf, sizeof(bf), fp) == NULL)
 223                         goto out_failure;
 224
 225                 if (memcmp(bf, "Name:", 5) == 0) {
 226                         char *name = bf + 5;
 227                         while (*name && isspace(*name))
 228                                 ++name;
 229                         size = strlen(name) - 1;
 230                         memcpy(comm_ev.comm, name, size++);
 231                 } else if (memcmp(bf, "Tgid:", 5) == 0) {
 232                         char *tgids = bf + 5;
 233                         while (*tgids && isspace(*tgids))
 234                                 ++tgids;
 235                         tgid = comm_ev.pid = atoi(tgids);
 236                 }
 237         }
 238
 239         comm_ev.header.type = PERF_RECORD_COMM;
 240         size = ALIGN(size, sizeof(u64));
 241         comm_ev.header.size = sizeof(comm_ev) - (sizeof(comm_ev.comm) - size);
 242
 243         if (!full) {
 244                 comm_ev.tid = pid;
 245
 246                 write_output(&comm_ev, comm_ev.header.size);
 247                 goto out_fclose;
 248         }
 249
 250         snprintf(filename, sizeof(filename), "/proc/%d/task", pid);
 251
 252         tasks = opendir(filename);
 253         while (!readdir_r(tasks, &dirent, &next) && next) {
 254                 char *end;
 255                 pid = strtol(dirent.d_name, &end, 10);
 256                 if (*end)
 257                         continue;
 258
 259                 comm_ev.tid = pid;
 260
 261                 write_output(&comm_ev, comm_ev.header.size);
 262         }
 263         closedir(tasks);
 264
 265 out_fclose:
 266         fclose(fp);
 267         return tgid;
 268
 269 out_failure:
 270         fprintf(stderr, "couldn't get COMM and pgid, malformed %s\n",
 271                 filename);
 272         exit(EXIT_FAILURE);
 273 }
 274
 275 static void pid_synthesize_mmap_samples(pid_t pid, pid_t tgid)
 276 {
 277         char filename[PATH_MAX];
 278         FILE *fp;
 279
 280         snprintf(filename, sizeof(filename), "/proc/%d/maps", pid);
 281
 282         fp = fopen(filename, "r");
 283         if (fp == NULL) {
 284                 /*
 285                  * We raced with a task exiting - just return:
 286                  */
 287                 if (verbose)
 288                         fprintf(stderr, "couldn't open %s\n", filename);
 289                 return;
 290         }
 291         while (1) {
 292                 char bf[BUFSIZ], *pbf = bf;
 293                 struct mmap_event mmap_ev = {
 294                         .header = { .type = PERF_RECORD_MMAP },
 295                 };
 296                 int n;
 297                 size_t size;
 298                 if (fgets(bf, sizeof(bf), fp) == NULL)
 299                         break;
 300
 301                 /* 00400000-0040c000 r-xp 00000000 fd:01 41038  /bin/cat */
 302                 n = hex2u64(pbf, &mmap_ev.start);
 303                 if (n < 0)
 304                         continue;
 305                 pbf += n + 1;
 306                 n = hex2u64(pbf, &mmap_ev.len);
 307                 if (n < 0)
 308                         continue;
 309                 pbf += n + 3;
 310                 if (*pbf == 'x') { /* vm_exec */
 311                         char *execname = strchr(bf, '/');
 312
 313                         /* Catch VDSO */
 314                         if (execname == NULL)
 315                                 execname = strstr(bf, "[vdso]");
 316
 317                         if (execname == NULL)
 318                                 continue;
 319
 320                         size = strlen(execname);
 321                         execname[size - 1] = '\0'; /* Remove \n */
 322                         memcpy(mmap_ev.filename, execname, size);
 323                         size = ALIGN(size, sizeof(u64));
 324                         mmap_ev.len -= mmap_ev.start;
 325                         mmap_ev.header.size = (sizeof(mmap_ev) -
 326                                                (sizeof(mmap_ev.filename) - size));
 327                         mmap_ev.pid = tgid;
 328                         mmap_ev.tid = pid;
 329
 330                         write_output(&mmap_ev, mmap_ev.header.size);
 331                 }
 332         }
 333
 334         fclose(fp);
 335 }
 336
 337 static void synthesize_all(void)
 338 {
 339         DIR *proc;
 340         struct dirent dirent, *next;
 341
 342         proc = opendir("/proc");
 343
 344         while (!readdir_r(proc, &dirent, &next) && next) {
 345                 char *end;
 346                 pid_t pid, tgid;
 347
 348                 pid = strtol(dirent.d_name, &end, 10);
 349                 if (*end) /* only interested in proper numerical dirents */
 350                         continue;
 351
 352                 tgid = pid_synthesize_comm_event(pid, 1);
 353                 pid_synthesize_mmap_samples(pid, tgid);
 354         }
 355
 356         closedir(proc);
 357 }
 358
 359 static int group_fd;
 360
 361 static struct perf_header_attr *get_header_attr(struct perf_event_attr *a, int nr)
 362 {
 363         struct perf_header_attr *h_attr;
 364
 365         if (nr < header->attrs) {
 366                 h_attr = header->attr[nr];
 367         } else {
 368                 h_attr = perf_header_attr__new(a);
 369                 perf_header__add_attr(header, h_attr);
 370         }
 371
 372         return h_attr;
 373 }
 374
 375 static void create_counter(int counter, int cpu, pid_t pid)
 376 {
 377         struct perf_event_attr *attr = attrs + counter;
 378         struct perf_header_attr *h_attr;
 379         int track = !counter; /* only the first counter needs these */
 380         struct {
 381                 u64 count;
 382                 u64 time_enabled;
 383                 u64 time_running;
 384                 u64 id;
 385         } read_data;
 386
 387         attr->read_format       = PERF_FORMAT_TOTAL_TIME_ENABLED |
 388                                   PERF_FORMAT_TOTAL_TIME_RUNNING |
 389                                   PERF_FORMAT_ID;
 390
 391         attr->sample_type       |= PERF_SAMPLE_IP | PERF_SAMPLE_TID;
 392
 393         if (freq) {
 394                 attr->sample_type       |= PERF_SAMPLE_PERIOD;
 395                 attr->freq              = 1;
 396                 attr->sample_freq       = freq;
 397         }
 398
 399         if (no_samples)
 400                 attr->sample_freq = 0;
 401
 402         if (inherit_stat)
 403                 attr->inherit_stat = 1;
 404
 405         if (sample_address)
 406                 attr->sample_type       |= PERF_SAMPLE_ADDR;
 407
 408         if (call_graph)
 409                 attr->sample_type       |= PERF_SAMPLE_CALLCHAIN;
 410
 411         if (raw_samples) {
 412                 attr->sample_type       |= PERF_SAMPLE_TIME;
 413                 attr->sample_type       |= PERF_SAMPLE_RAW;
 414                 attr->sample_type       |= PERF_SAMPLE_CPU;
 415         }
 416
 417         attr->mmap              = track;
 418         attr->comm              = track;
 419         attr->inherit           = (cpu < 0) && inherit;
 420         attr->disabled          = 1;
 421
 422 try_again:
 423         fd[nr_cpu][counter] = sys_perf_event_open(attr, pid, cpu, group_fd, 0);
 424
 425         if (fd[nr_cpu][counter] < 0) {
 426                 int err = errno;
 427
 428                 if (err == EPERM)
 429                         die("Permission error - are you root?\n");
 430                 else if (err ==  ENODEV && profile_cpu != -1)
 431                         die("No such device - did you specify an out-of-range profile CPU?\n");
 432
 433                 /*
 434                  * If it's cycles then fall back to hrtimer
 435                  * based cpu-clock-tick sw counter, which
 436                  * is always available even if no PMU support:
 437                  */
 438                 if (attr->type == PERF_TYPE_HARDWARE
 439                         && attr->config == PERF_COUNT_HW_CPU_CYCLES) {
 440
 441                         if (verbose)
 442                                 warning(" ... trying to fall back to cpu-clock-ticks\n");
 443                         attr->type = PERF_TYPE_SOFTWARE;
 444                         attr->config = PERF_COUNT_SW_CPU_CLOCK;
 445                         goto try_again;
 446                 }
 447                 printf("\n");
 448                 error("perfcounter syscall returned with %d (%s)\n",
 449                         fd[nr_cpu][counter], strerror(err));
 450                 die("No CONFIG_PERF_EVENTS=y kernel support configured?\n");
 451                 exit(-1);
 452         }
 453
 454         h_attr = get_header_attr(attr, counter);
 455
 456         if (!file_new) {
 457                 if (memcmp(&h_attr->attr, attr, sizeof(*attr))) {
 458                         fprintf(stderr, "incompatible append\n");
 459                         exit(-1);
 460                 }
 461         }
 462
 463         if (read(fd[nr_cpu][counter], &read_data, sizeof(read_data)) == -1) {
 464                 perror("Unable to read perf file descriptor\n");
 465                 exit(-1);
 466         }
 467
 468         perf_header_attr__add_id(h_attr, read_data.id);
 469
 470         assert(fd[nr_cpu][counter] >= 0);
 471         fcntl(fd[nr_cpu][counter], F_SETFL, O_NONBLOCK);
 472
 473         /*
 474          * First counter acts as the group leader:
 475          */
 476         if (group && group_fd == -1)
 477                 group_fd = fd[nr_cpu][counter];
 478         if (multiplex && multiplex_fd == -1)
 479                 multiplex_fd = fd[nr_cpu][counter];
 480
 481         if (multiplex && fd[nr_cpu][counter] != multiplex_fd) {
 482                 int ret;
 483
 484                 ret = ioctl(fd[nr_cpu][counter], PERF_EVENT_IOC_SET_OUTPUT, multiplex_fd);
 485                 assert(ret != -1);
 486         } else {
 487                 event_array[nr_poll].fd = fd[nr_cpu][counter];
 488                 event_array[nr_poll].events = POLLIN;
 489                 nr_poll++;
 490
 491                 mmap_array[nr_cpu][counter].counter = counter;
 492                 mmap_array[nr_cpu][counter].prev = 0;
 493                 mmap_array[nr_cpu][counter].mask = mmap_pages*page_size - 1;
 494                 mmap_array[nr_cpu][counter].base = mmap(NULL, (mmap_pages+1)*page_size,
 495                                 PROT_READ|PROT_WRITE, MAP_SHARED, fd[nr_cpu][counter], 0);
 496                 if (mmap_array[nr_cpu][counter].base == MAP_FAILED) {
 497                         error("failed to mmap with %d (%s)\n", errno, strerror(errno));
 498                         exit(-1);
 499                 }
 500         }
 501
 502         ioctl(fd[nr_cpu][counter], PERF_EVENT_IOC_ENABLE);
 503 }
 504
 505 static void open_counters(int cpu, pid_t pid)
 506 {
 507         int counter;
 508
 509         group_fd = -1;
 510         for (counter = 0; counter < nr_counters; counter++)
 511                 create_counter(counter, cpu, pid);
 512
 513         nr_cpu++;
 514 }
 515
 516 static void atexit_header(void)
 517 {
 518         header->data_size += bytes_written;
 519
 520         perf_header__write(header, output);
 521 }
 522
 523 static int __cmd_record(int argc, const char **argv)
 524 {
 525         int i, counter;
 526         struct stat st;
 527         pid_t pid = 0;
 528         int flags;
 529         int ret;
 530         unsigned long waking = 0;
 531
 532         page_size = sysconf(_SC_PAGE_SIZE);
 533         nr_cpus = sysconf(_SC_NPROCESSORS_ONLN);
 534         assert(nr_cpus <= MAX_NR_CPUS);
 535         assert(nr_cpus >= 0);
 536
 537         atexit(sig_atexit);
 538         signal(SIGCHLD, sig_handler);
 539         signal(SIGINT, sig_handler);
 540
 541         if (!stat(output_name, &st) && st.st_size) {
 542                 if (!force && !append_file) {
 543                         fprintf(stderr, "Error, output file %s exists, use -A to append or -f to overwrite.\n",
 544                                         output_name);
 545                         exit(-1);
 546                 }
 547         } else {
 548                 append_file = 0;
 549         }
 550
 551         flags = O_CREAT|O_RDWR;
 552         if (append_file)
 553                 file_new = 0;
 554         else
 555                 flags |= O_TRUNC;
 556
 557         output = open(output_name, flags, S_IRUSR|S_IWUSR);
 558         if (output < 0) {
 559                 perror("failed to create output file");
 560                 exit(-1);
 561         }
 562
 563         if (!file_new)
 564                 header = perf_header__read(output);
 565         else
 566                 header = perf_header__new();
 567
 568         if (raw_samples) {
 569                 perf_header__set_trace_info();
 570         } else {
 571                 for (i = 0; i < nr_counters; i++) {
 572                         if (attrs[i].sample_type & PERF_SAMPLE_RAW) {
 573                                 perf_header__set_trace_info();
 574                                 break;
 575                         }
 576                 }
 577         }
 578
 579         atexit(atexit_header);
 580
 581         if (!system_wide) {
 582                 pid = target_pid;
 583                 if (pid == -1)
 584                         pid = getpid();
 585
 586                 open_counters(profile_cpu, pid);
 587         } else {
 588                 if (profile_cpu != -1) {
 589                         open_counters(profile_cpu, target_pid);
 590                 } else {
 591                         for (i = 0; i < nr_cpus; i++)
 592                                 open_counters(i, target_pid);
 593                 }
 594         }
 595
 596         if (file_new)
 597                 perf_header__write(header, output);
 598
 599         if (!system_wide) {
 600                 pid_t tgid = pid_synthesize_comm_event(pid, 0);
 601                 pid_synthesize_mmap_samples(pid, tgid);
 602         } else
 603                 synthesize_all();
 604
 605         if (target_pid == -1 && argc) {
 606                 pid = fork();
 607                 if (pid < 0)
 608                         perror("failed to fork");
 609
 610                 if (!pid) {
 611                         if (execvp(argv[0], (char **)argv)) {
 612                                 perror(argv[0]);
 613                                 exit(-1);
 614                         }
 615                 }
 616
 617                 child_pid = pid;
 618         }
 619
 620         if (realtime_prio) {
 621                 struct sched_param param;
 622
 623                 param.sched_priority = realtime_prio;
 624                 if (sched_setscheduler(0, SCHED_FIFO, &param)) {
 625                         printf("Could not set realtime priority.\n");
 626                         exit(-1);
 627                 }
 628         }
 629
 630         for (;;) {
 631                 int hits = samples;
 632
 633                 for (i = 0; i < nr_cpu; i++) {
 634                         for (counter = 0; counter < nr_counters; counter++) {
 635                                 if (mmap_array[i][counter].base)
 636                                         mmap_read(&mmap_array[i][counter]);
 637                         }
 638                 }
 639
 640                 if (hits == samples) {
 641                         if (done)
 642                                 break;
 643                         ret = poll(event_array, nr_poll, -1);
 644                         waking++;
 645                 }
 646
 647                 if (done) {
 648                         for (i = 0; i < nr_cpu; i++) {
 649                                 for (counter = 0; counter < nr_counters; counter++)
 650                                         ioctl(fd[i][counter], PERF_EVENT_IOC_DISABLE);
 651                         }
 652                 }
 653         }
 654
 655         fprintf(stderr, "[ perf record: Woken up %ld times to write data ]\n", waking);
 656
 657         /*
 658          * Approximate RIP event size: 24 bytes.
 659          */
 660         fprintf(stderr,
 661                 "[ perf record: Captured and wrote %.3f MB %s (~%lld samples) ]\n",
 662                 (double)bytes_written / 1024.0 / 1024.0,
 663                 output_name,
 664                 bytes_written / 24);
 665
 666         return 0;
 667 }
 668
 669 static const char * const record_usage[] = {
 670         "perf record [<options>] [<command>]",
 671         "perf record [<options>] -- <command> [<options>]",
 672         NULL
 673 };
 674
 675 static const struct option options[] = {
 676         OPT_CALLBACK('e', "event", NULL, "event",
 677                      "event selector. use 'perf list' to list available events",
 678                      parse_events),
 679         OPT_INTEGER('p', "pid", &target_pid,
 680                     "record events on existing pid"),
 681         OPT_INTEGER('r', "realtime", &realtime_prio,
 682                     "collect data with this RT SCHED_FIFO priority"),
 683         OPT_BOOLEAN('R', "raw-samples", &raw_samples,
 684                     "collect raw sample records from all opened counters"),
 685         OPT_BOOLEAN('a', "all-cpus", &system_wide,
 686                             "system-wide collection from all CPUs"),
 687         OPT_BOOLEAN('A', "append", &append_file,
 688                             "append to the output file to do incremental profiling"),
 689         OPT_INTEGER('C', "profile_cpu", &profile_cpu,
 690                             "CPU to profile on"),
 691         OPT_BOOLEAN('f', "force", &force,
 692                         "overwrite existing data file"),
 693         OPT_LONG('c', "count", &default_interval,
 694                     "event period to sample"),
 695         OPT_STRING('o', "output", &output_name, "file",
 696                     "output file name"),
 697         OPT_BOOLEAN('i', "inherit", &inherit,
 698                     "child tasks inherit counters"),
 699         OPT_INTEGER('F', "freq", &freq,
 700                     "profile at this frequency"),
 701         OPT_INTEGER('m', "mmap-pages", &mmap_pages,
 702                     "number of mmap data pages"),
 703         OPT_BOOLEAN('g', "call-graph", &call_graph,
 704                     "do call-graph (stack chain/backtrace) recording"),
 705         OPT_BOOLEAN('v', "verbose", &verbose,
 706                     "be more verbose (show counter open errors, etc)"),
 707         OPT_BOOLEAN('s', "stat", &inherit_stat,
 708                     "per thread counts"),
 709         OPT_BOOLEAN('d', "data", &sample_address,
 710                     "Sample addresses"),
 711         OPT_BOOLEAN('n', "no-samples", &no_samples,
 712                     "don't sample"),
 713         OPT_BOOLEAN('M', "multiplex", &multiplex,
 714                     "multiplex counter output in a single channel"),
 715         OPT_END()
 716 };
 717
 718 int cmd_record(int argc, const char **argv, const char *prefix __used)
 719 {
 720         int counter;
 721
 722         argc = parse_options(argc, argv, options, record_usage,
 723                 PARSE_OPT_STOP_AT_NON_OPTION);
 724         if (!argc && target_pid == -1 && !system_wide)
 725                 usage_with_options(record_usage, options);
 726
 727         if (!nr_counters) {
 728                 nr_counters     = 1;
 729                 attrs[0].type   = PERF_TYPE_HARDWARE;
 730                 attrs[0].config = PERF_COUNT_HW_CPU_CYCLES;
 731         }
 732
 733         /*
 734          * User specified count overrides default frequency.
 735          */
 736         if (default_interval)
 737                 freq = 0;
 738         else if (freq) {
 739                 default_interval = freq;
 740         } else {
 741                 fprintf(stderr, "frequency and count are zero, aborting\n");
 742                 exit(EXIT_FAILURE);
 743         }
 744
 745         for (counter = 0; counter < nr_counters; counter++) {
 746                 if (attrs[counter].sample_period)
 747                         continue;
 748
 749                 attrs[counter].sample_period = default_interval;
 750         }
 751
 752         return __cmd_record(argc, argv);
 753 }