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 #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");
 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");
 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                        "Symbol resolution may be skewed if relocation was used (e.g. kexec).\n"
 703                        "Check /proc/kallsyms permission or run as root.\n");
 704
 705         err = event__synthesize_modules(process_synthesized_event,
 706                                         session, machine);
 707         if (err < 0)
 708                 pr_err("Couldn't record kernel module information.\n"
 709                        "Symbol resolution may be skewed if relocation was used (e.g. kexec).\n"
 710                        "Check /proc/modules permission or run as root.\n");
 711
 712         if (perf_guest)
 713                 perf_session__process_machines(session, event__synthesize_guest_os);
 714
 715         if (!system_wide)
 716                 event__synthesize_thread(target_tid, process_synthesized_event,
 717                                          session);
 718         else
 719                 event__synthesize_threads(process_synthesized_event, session);
 720
 721         if (realtime_prio) {
 722                 struct sched_param param;
 723
 724                 param.sched_priority = realtime_prio;
 725                 if (sched_setscheduler(0, SCHED_FIFO, &param)) {
 726                         pr_err("Could not set realtime priority.\n");
 727                         exit(-1);
 728                 }
 729         }
 730
 731         /*
 732          * Let the child rip
 733          */
 734         if (forks)
 735                 close(go_pipe[1]);
 736
 737         for (;;) {
 738                 int hits = samples;
 739                 int thread;
 740
 741                 mmap_read_all();
 742
 743                 if (hits == samples) {
 744                         if (done)
 745                                 break;
 746                         err = poll(event_array, nr_poll, -1);
 747                         waking++;
 748                 }
 749
 750                 if (done) {
 751                         for (i = 0; i < nr_cpu; i++) {
 752                                 for (counter = 0;
 753                                         counter < nr_counters;
 754                                         counter++) {
 755                                         for (thread = 0;
 756                                                 thread < thread_num;
 757                                                 thread++)
 758                                                 ioctl(fd[i][counter][thread],
 759                                                         PERF_EVENT_IOC_DISABLE);
 760                                 }
 761                         }
 762                 }
 763         }
 764
 765         if (quiet)
 766                 return 0;
 767
 768         fprintf(stderr, "[ perf record: Woken up %ld times to write data ]\n", waking);
 769
 770         /*
 771          * Approximate RIP event size: 24 bytes.
 772          */
 773         fprintf(stderr,
 774                 "[ perf record: Captured and wrote %.3f MB %s (~%lld samples) ]\n",
 775                 (double)bytes_written / 1024.0 / 1024.0,
 776                 output_name,
 777                 bytes_written / 24);
 778
 779         return 0;
 780
 781 out_delete_session:
 782         perf_session__delete(session);
 783         return err;
 784 }
 785
 786 static const char * const record_usage[] = {
 787         "perf record [<options>] [<command>]",
 788         "perf record [<options>] -- <command> [<options>]",
 789         NULL
 790 };
 791
 792 static bool force, append_file;
 793
 794 const struct option record_options[] = {
 795         OPT_CALLBACK('e', "event", NULL, "event",
 796                      "event selector. use 'perf list' to list available events",
 797                      parse_events),
 798         OPT_CALLBACK(0, "filter", NULL, "filter",
 799                      "event filter", parse_filter),
 800         OPT_INTEGER('p', "pid", &target_pid,
 801                     "record events on existing process id"),
 802         OPT_INTEGER('t', "tid", &target_tid,
 803                     "record events on existing thread id"),
 804         OPT_INTEGER('r', "realtime", &realtime_prio,
 805                     "collect data with this RT SCHED_FIFO priority"),
 806         OPT_BOOLEAN('R', "raw-samples", &raw_samples,
 807                     "collect raw sample records from all opened counters"),
 808         OPT_BOOLEAN('a', "all-cpus", &system_wide,
 809                             "system-wide collection from all CPUs"),
 810         OPT_BOOLEAN('A', "append", &append_file,
 811                             "append to the output file to do incremental profiling"),
 812         OPT_STRING('C', "cpu", &cpu_list, "cpu",
 813                     "list of cpus to monitor"),
 814         OPT_BOOLEAN('f', "force", &force,
 815                         "overwrite existing data file (deprecated)"),
 816         OPT_U64('c', "count", &user_interval, "event period to sample"),
 817         OPT_STRING('o', "output", &output_name, "file",
 818                     "output file name"),
 819         OPT_BOOLEAN('i', "no-inherit", &no_inherit,
 820                     "child tasks do not inherit counters"),
 821         OPT_UINTEGER('F', "freq", &user_freq, "profile at this frequency"),
 822         OPT_UINTEGER('m', "mmap-pages", &mmap_pages, "number of mmap data pages"),
 823         OPT_BOOLEAN('g', "call-graph", &call_graph,
 824                     "do call-graph (stack chain/backtrace) recording"),
 825         OPT_INCR('v', "verbose", &verbose,
 826                     "be more verbose (show counter open errors, etc)"),
 827         OPT_BOOLEAN('q', "quiet", &quiet, "don't print any message"),
 828         OPT_BOOLEAN('s', "stat", &inherit_stat,
 829                     "per thread counts"),
 830         OPT_BOOLEAN('d', "data", &sample_address,
 831                     "Sample addresses"),
 832         OPT_BOOLEAN('n', "no-samples", &no_samples,
 833                     "don't sample"),
 834         OPT_BOOLEAN('N', "no-buildid-cache", &no_buildid,
 835                     "do not update the buildid cache"),
 836         OPT_END()
 837 };
 838
 839 int cmd_record(int argc, const char **argv, const char *prefix __used)
 840 {
 841         int i, j, err = -ENOMEM;
 842
 843         argc = parse_options(argc, argv, record_options, record_usage,
 844                             PARSE_OPT_STOP_AT_NON_OPTION);
 845         if (!argc && target_pid == -1 && target_tid == -1 &&
 846                 !system_wide && !cpu_list)
 847                 usage_with_options(record_usage, record_options);
 848
 849         if (force && append_file) {
 850                 fprintf(stderr, "Can't overwrite and append at the same time."
 851                                 " You need to choose between -f and -A");
 852                 usage_with_options(record_usage, record_options);
 853         } else if (append_file) {
 854                 write_mode = WRITE_APPEND;
 855         } else {
 856                 write_mode = WRITE_FORCE;
 857         }
 858
 859         symbol__init();
 860         if (no_buildid)
 861                 disable_buildid_cache();
 862
 863         if (!nr_counters) {
 864                 nr_counters     = 1;
 865                 attrs[0].type   = PERF_TYPE_HARDWARE;
 866                 attrs[0].config = PERF_COUNT_HW_CPU_CYCLES;
 867         }
 868
 869         if (target_pid != -1) {
 870                 target_tid = target_pid;
 871                 thread_num = find_all_tid(target_pid, &all_tids);
 872                 if (thread_num <= 0) {
 873                         fprintf(stderr, "Can't find all threads of pid %d\n",
 874                                         target_pid);
 875                         usage_with_options(record_usage, record_options);
 876                 }
 877         } else {
 878                 all_tids=malloc(sizeof(pid_t));
 879                 if (!all_tids)
 880                         goto out_symbol_exit;
 881
 882                 all_tids[0] = target_tid;
 883                 thread_num = 1;
 884         }
 885
 886         for (i = 0; i < MAX_NR_CPUS; i++) {
 887                 for (j = 0; j < MAX_COUNTERS; j++) {
 888                         fd[i][j] = malloc(sizeof(int)*thread_num);
 889                         if (!fd[i][j])
 890                                 goto out_free_fd;
 891                 }
 892         }
 893         event_array = malloc(
 894                 sizeof(struct pollfd)*MAX_NR_CPUS*MAX_COUNTERS*thread_num);
 895         if (!event_array)
 896                 goto out_free_fd;
 897
 898         if (user_interval != ULLONG_MAX)
 899                 default_interval = user_interval;
 900         if (user_freq != UINT_MAX)
 901                 freq = user_freq;
 902
 903         /*
 904          * User specified count overrides default frequency.
 905          */
 906         if (default_interval)
 907                 freq = 0;
 908         else if (freq) {
 909                 default_interval = freq;
 910         } else {
 911                 fprintf(stderr, "frequency and count are zero, aborting\n");
 912                 err = -EINVAL;
 913                 goto out_free_event_array;
 914         }
 915
 916         err = __cmd_record(argc, argv);
 917
 918 out_free_event_array:
 919         free(event_array);
 920 out_free_fd:
 921         for (i = 0; i < MAX_NR_CPUS; i++) {
 922                 for (j = 0; j < MAX_COUNTERS; j++)
 923                         free(fd[i][j]);
 924         }
 925         free(all_tids);
 926         all_tids = NULL;
 927 out_symbol_exit:
 928         symbol__exit();
 929         return err;
 930 }