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 static u64                      sample_type;
  40
  41 static int                      nr_cpus                         =      0;
  42 static unsigned int             page_size;
  43 static unsigned int             mmap_pages                      =    128;
  44 static unsigned int             user_freq                       = UINT_MAX;
  45 static int                      freq                            =   1000;
  46 static int                      output;
  47 static int                      pipe_output                     =      0;
  48 static const char               *output_name                    = "perf.data";
  49 static int                      group                           =      0;
  50 static int                      realtime_prio                   =      0;
  51 static bool                     raw_samples                     =  false;
  52 static bool                     sample_id_all_avail             =   true;
  53 static bool                     system_wide                     =  false;
  54 static pid_t                    target_pid                      =     -1;
  55 static pid_t                    target_tid                      =     -1;
  56 static pid_t                    *all_tids                       =      NULL;
  57 static int                      thread_num                      =      0;
  58 static pid_t                    child_pid                       =     -1;
  59 static bool                     no_inherit                      =  false;
  60 static enum write_mode_t        write_mode                      = WRITE_FORCE;
  61 static bool                     call_graph                      =  false;
  62 static bool                     inherit_stat                    =  false;
  63 static bool                     no_samples                      =  false;
  64 static bool                     sample_address                  =  false;
  65 static bool                     sample_time                     =  false;
  66 static bool                     no_buildid                      =  false;
  67 static bool                     no_buildid_cache                =  false;
  68
  69 static long                     samples                         =      0;
  70 static u64                      bytes_written                   =      0;
  71
  72 static struct pollfd            *event_array;
  73
  74 static int                      nr_poll                         =      0;
  75 static int                      nr_cpu                          =      0;
  76
  77 static int                      file_new                        =      1;
  78 static off_t                    post_processing_offset;
  79
  80 static struct perf_session      *session;
  81 static const char               *cpu_list;
  82
  83 struct mmap_data {
  84         int                     counter;
  85         void                    *base;
  86         unsigned int            mask;
  87         unsigned int            prev;
  88 };
  89
  90 static struct mmap_data         mmap_array[MAX_NR_CPUS];
  91
  92 static unsigned long mmap_read_head(struct mmap_data *md)
  93 {
  94         struct perf_event_mmap_page *pc = md->base;
  95         long head;
  96
  97         head = pc->data_head;
  98         rmb();
  99
 100         return head;
 101 }
 102
 103 static void mmap_write_tail(struct mmap_data *md, unsigned long tail)
 104 {
 105         struct perf_event_mmap_page *pc = md->base;
 106
 107         /*
 108          * ensure all reads are done before we write the tail out.
 109          */
 110         /* mb(); */
 111         pc->data_tail = tail;
 112 }
 113
 114 static void advance_output(size_t size)
 115 {
 116         bytes_written += size;
 117 }
 118
 119 static void write_output(void *buf, size_t size)
 120 {
 121         while (size) {
 122                 int ret = write(output, buf, size);
 123
 124                 if (ret < 0)
 125                         die("failed to write");
 126
 127                 size -= ret;
 128                 buf += ret;
 129
 130                 bytes_written += ret;
 131         }
 132 }
 133
 134 static int process_synthesized_event(event_t *event,
 135                                      struct sample_data *sample __used,
 136                                      struct perf_session *self __used)
 137 {
 138         write_output(event, event->header.size);
 139         return 0;
 140 }
 141
 142 static void mmap_read(struct mmap_data *md)
 143 {
 144         unsigned int head = mmap_read_head(md);
 145         unsigned int old = md->prev;
 146         unsigned char *data = md->base + page_size;
 147         unsigned long size;
 148         void *buf;
 149         int diff;
 150
 151         /*
 152          * If we're further behind than half the buffer, there's a chance
 153          * the writer will bite our tail and mess up the samples under us.
 154          *
 155          * If we somehow ended up ahead of the head, we got messed up.
 156          *
 157          * In either case, truncate and restart at head.
 158          */
 159         diff = head - old;
 160         if (diff < 0) {
 161                 fprintf(stderr, "WARNING: failed to keep up with mmap data\n");
 162                 /*
 163                  * head points to a known good entry, start there.
 164                  */
 165                 old = head;
 166         }
 167
 168         if (old != head)
 169                 samples++;
 170
 171         size = head - old;
 172
 173         if ((old & md->mask) + size != (head & md->mask)) {
 174                 buf = &data[old & md->mask];
 175                 size = md->mask + 1 - (old & md->mask);
 176                 old += size;
 177
 178                 write_output(buf, size);
 179         }
 180
 181         buf = &data[old & md->mask];
 182         size = head - old;
 183         old += size;
 184
 185         write_output(buf, size);
 186
 187         md->prev = old;
 188         mmap_write_tail(md, old);
 189 }
 190
 191 static volatile int done = 0;
 192 static volatile int signr = -1;
 193
 194 static void sig_handler(int sig)
 195 {
 196         done = 1;
 197         signr = sig;
 198 }
 199
 200 static void sig_atexit(void)
 201 {
 202         if (child_pid > 0)
 203                 kill(child_pid, SIGTERM);
 204
 205         if (signr == -1)
 206                 return;
 207
 208         signal(signr, SIG_DFL);
 209         kill(getpid(), signr);
 210 }
 211
 212 static int group_fd;
 213
 214 static struct perf_header_attr *get_header_attr(struct perf_event_attr *a, int nr)
 215 {
 216         struct perf_header_attr *h_attr;
 217
 218         if (nr < session->header.attrs) {
 219                 h_attr = session->header.attr[nr];
 220         } else {
 221                 h_attr = perf_header_attr__new(a);
 222                 if (h_attr != NULL)
 223                         if (perf_header__add_attr(&session->header, h_attr) < 0) {
 224                                 perf_header_attr__delete(h_attr);
 225                                 h_attr = NULL;
 226                         }
 227         }
 228
 229         return h_attr;
 230 }
 231
 232 static void create_counter(int counter, int cpu)
 233 {
 234         char *filter = filters[counter];
 235         struct perf_event_attr *attr = attrs + counter;
 236         struct perf_header_attr *h_attr;
 237         int track = !counter; /* only the first counter needs these */
 238         int thread_index;
 239         int ret;
 240         struct {
 241                 u64 count;
 242                 u64 time_enabled;
 243                 u64 time_running;
 244                 u64 id;
 245         } read_data;
 246
 247         attr->read_format       = PERF_FORMAT_TOTAL_TIME_ENABLED |
 248                                   PERF_FORMAT_TOTAL_TIME_RUNNING |
 249                                   PERF_FORMAT_ID;
 250
 251         attr->sample_type       |= PERF_SAMPLE_IP | PERF_SAMPLE_TID;
 252
 253         if (nr_counters > 1)
 254                 attr->sample_type |= PERF_SAMPLE_ID;
 255
 256         /*
 257          * We default some events to a 1 default interval. But keep
 258          * it a weak assumption overridable by the user.
 259          */
 260         if (!attr->sample_period || (user_freq != UINT_MAX &&
 261                                      user_interval != ULLONG_MAX)) {
 262                 if (freq) {
 263                         attr->sample_type       |= PERF_SAMPLE_PERIOD;
 264                         attr->freq              = 1;
 265                         attr->sample_freq       = freq;
 266                 } else {
 267                         attr->sample_period = default_interval;
 268                 }
 269         }
 270
 271         if (no_samples)
 272                 attr->sample_freq = 0;
 273
 274         if (inherit_stat)
 275                 attr->inherit_stat = 1;
 276
 277         if (sample_address) {
 278                 attr->sample_type       |= PERF_SAMPLE_ADDR;
 279                 attr->mmap_data = track;
 280         }
 281
 282         if (call_graph)
 283                 attr->sample_type       |= PERF_SAMPLE_CALLCHAIN;
 284
 285         if (system_wide)
 286                 attr->sample_type       |= PERF_SAMPLE_CPU;
 287
 288         if (sample_time)
 289                 attr->sample_type       |= PERF_SAMPLE_TIME;
 290
 291         if (raw_samples) {
 292                 attr->sample_type       |= PERF_SAMPLE_TIME;
 293                 attr->sample_type       |= PERF_SAMPLE_RAW;
 294                 attr->sample_type       |= PERF_SAMPLE_CPU;
 295         }
 296
 297         if (!sample_type)
 298                 sample_type = attr->sample_type;
 299
 300         attr->mmap              = track;
 301         attr->comm              = track;
 302         attr->inherit           = !no_inherit;
 303         if (target_pid == -1 && target_tid == -1 && !system_wide) {
 304                 attr->disabled = 1;
 305                 attr->enable_on_exec = 1;
 306         }
 307 retry_sample_id:
 308         attr->sample_id_all = sample_id_all_avail ? 1 : 0;
 309
 310         for (thread_index = 0; thread_index < thread_num; thread_index++) {
 311 try_again:
 312                 fd[nr_cpu][counter][thread_index] = sys_perf_event_open(attr,
 313                                 all_tids[thread_index], cpu, group_fd, 0);
 314
 315                 if (fd[nr_cpu][counter][thread_index] < 0) {
 316                         int err = errno;
 317
 318                         if (err == EPERM || err == EACCES)
 319                                 die("Permission error - are you root?\n"
 320                                         "\t Consider tweaking"
 321                                         " /proc/sys/kernel/perf_event_paranoid.\n");
 322                         else if (err ==  ENODEV && cpu_list) {
 323                                 die("No such device - did you specify"
 324                                         " an out-of-range profile CPU?\n");
 325                         } else if (err == EINVAL && sample_id_all_avail) {
 326                                 /*
 327                                  * Old kernel, no attr->sample_id_type_all field
 328                                  */
 329                                 sample_id_all_avail = false;
 330                                 goto retry_sample_id;
 331                         }
 332
 333                         /*
 334                          * If it's cycles then fall back to hrtimer
 335                          * based cpu-clock-tick sw counter, which
 336                          * is always available even if no PMU support:
 337                          */
 338                         if (attr->type == PERF_TYPE_HARDWARE
 339                                         && attr->config == PERF_COUNT_HW_CPU_CYCLES) {
 340
 341                                 if (verbose)
 342                                         warning(" ... trying to fall back to cpu-clock-ticks\n");
 343                                 attr->type = PERF_TYPE_SOFTWARE;
 344                                 attr->config = PERF_COUNT_SW_CPU_CLOCK;
 345                                 goto try_again;
 346                         }
 347                         printf("\n");
 348                         error("sys_perf_event_open() syscall returned with %d (%s).  /bin/dmesg may provide additional information.\n",
 349                                         fd[nr_cpu][counter][thread_index], strerror(err));
 350
 351 #if defined(__i386__) || defined(__x86_64__)
 352                         if (attr->type == PERF_TYPE_HARDWARE && err == EOPNOTSUPP)
 353                                 die("No hardware sampling interrupt available."
 354                                     " No APIC? If so then you can boot the kernel"
 355                                     " with the \"lapic\" boot parameter to"
 356                                     " force-enable it.\n");
 357 #endif
 358
 359                         die("No CONFIG_PERF_EVENTS=y kernel support configured?\n");
 360                         exit(-1);
 361                 }
 362
 363                 h_attr = get_header_attr(attr, counter);
 364                 if (h_attr == NULL)
 365                         die("nomem\n");
 366
 367                 if (!file_new) {
 368                         if (memcmp(&h_attr->attr, attr, sizeof(*attr))) {
 369                                 fprintf(stderr, "incompatible append\n");
 370                                 exit(-1);
 371                         }
 372                 }
 373
 374                 if (read(fd[nr_cpu][counter][thread_index], &read_data, sizeof(read_data)) == -1) {
 375                         perror("Unable to read perf file descriptor");
 376                         exit(-1);
 377                 }
 378
 379                 if (perf_header_attr__add_id(h_attr, read_data.id) < 0) {
 380                         pr_warning("Not enough memory to add id\n");
 381                         exit(-1);
 382                 }
 383
 384                 assert(fd[nr_cpu][counter][thread_index] >= 0);
 385                 fcntl(fd[nr_cpu][counter][thread_index], F_SETFL, O_NONBLOCK);
 386
 387                 /*
 388                  * First counter acts as the group leader:
 389                  */
 390                 if (group && group_fd == -1)
 391                         group_fd = fd[nr_cpu][counter][thread_index];
 392
 393                 if (counter || thread_index) {
 394                         ret = ioctl(fd[nr_cpu][counter][thread_index],
 395                                         PERF_EVENT_IOC_SET_OUTPUT,
 396                                         fd[nr_cpu][0][0]);
 397                         if (ret) {
 398                                 error("failed to set output: %d (%s)\n", errno,
 399                                                 strerror(errno));
 400                                 exit(-1);
 401                         }
 402                 } else {
 403                         mmap_array[nr_cpu].counter = counter;
 404                         mmap_array[nr_cpu].prev = 0;
 405                         mmap_array[nr_cpu].mask = mmap_pages*page_size - 1;
 406                         mmap_array[nr_cpu].base = mmap(NULL, (mmap_pages+1)*page_size,
 407                                 PROT_READ|PROT_WRITE, MAP_SHARED, fd[nr_cpu][counter][thread_index], 0);
 408                         if (mmap_array[nr_cpu].base == MAP_FAILED) {
 409                                 error("failed to mmap with %d (%s)\n", errno, strerror(errno));
 410                                 exit(-1);
 411                         }
 412
 413                         event_array[nr_poll].fd = fd[nr_cpu][counter][thread_index];
 414                         event_array[nr_poll].events = POLLIN;
 415                         nr_poll++;
 416                 }
 417
 418                 if (filter != NULL) {
 419                         ret = ioctl(fd[nr_cpu][counter][thread_index],
 420                                         PERF_EVENT_IOC_SET_FILTER, filter);
 421                         if (ret) {
 422                                 error("failed to set filter with %d (%s)\n", errno,
 423                                                 strerror(errno));
 424                                 exit(-1);
 425                         }
 426                 }
 427         }
 428 }
 429
 430 static void open_counters(int cpu)
 431 {
 432         int counter;
 433
 434         group_fd = -1;
 435         for (counter = 0; counter < nr_counters; counter++)
 436                 create_counter(counter, cpu);
 437
 438         nr_cpu++;
 439 }
 440
 441 static int process_buildids(void)
 442 {
 443         u64 size = lseek(output, 0, SEEK_CUR);
 444
 445         if (size == 0)
 446                 return 0;
 447
 448         session->fd = output;
 449         return __perf_session__process_events(session, post_processing_offset,
 450                                               size - post_processing_offset,
 451                                               size, &build_id__mark_dso_hit_ops);
 452 }
 453
 454 static void atexit_header(void)
 455 {
 456         if (!pipe_output) {
 457                 session->header.data_size += bytes_written;
 458
 459                 if (!no_buildid)
 460                         process_buildids();
 461                 perf_header__write(&session->header, output, true);
 462                 perf_session__delete(session);
 463                 symbol__exit();
 464         }
 465 }
 466
 467 static void event__synthesize_guest_os(struct machine *machine, void *data)
 468 {
 469         int err;
 470         struct perf_session *psession = data;
 471
 472         if (machine__is_host(machine))
 473                 return;
 474
 475         /*
 476          *As for guest kernel when processing subcommand record&report,
 477          *we arrange module mmap prior to guest kernel mmap and trigger
 478          *a preload dso because default guest module symbols are loaded
 479          *from guest kallsyms instead of /lib/modules/XXX/XXX. This
 480          *method is used to avoid symbol missing when the first addr is
 481          *in module instead of in guest kernel.
 482          */
 483         err = event__synthesize_modules(process_synthesized_event,
 484                                         psession, machine);
 485         if (err < 0)
 486                 pr_err("Couldn't record guest kernel [%d]'s reference"
 487                        " relocation symbol.\n", machine->pid);
 488
 489         /*
 490          * We use _stext for guest kernel because guest kernel's /proc/kallsyms
 491          * have no _text sometimes.
 492          */
 493         err = event__synthesize_kernel_mmap(process_synthesized_event,
 494                                             psession, machine, "_text");
 495         if (err < 0)
 496                 err = event__synthesize_kernel_mmap(process_synthesized_event,
 497                                                     psession, machine, "_stext");
 498         if (err < 0)
 499                 pr_err("Couldn't record guest kernel [%d]'s reference"
 500                        " relocation symbol.\n", machine->pid);
 501 }
 502
 503 static struct perf_event_header finished_round_event = {
 504         .size = sizeof(struct perf_event_header),
 505         .type = PERF_RECORD_FINISHED_ROUND,
 506 };
 507
 508 static void mmap_read_all(void)
 509 {
 510         int i;
 511
 512         for (i = 0; i < nr_cpu; i++) {
 513                 if (mmap_array[i].base)
 514                         mmap_read(&mmap_array[i]);
 515         }
 516
 517         if (perf_header__has_feat(&session->header, HEADER_TRACE_INFO))
 518                 write_output(&finished_round_event, sizeof(finished_round_event));
 519 }
 520
 521 static int __cmd_record(int argc, const char **argv)
 522 {
 523         int i, counter;
 524         struct stat st;
 525         int flags;
 526         int err;
 527         unsigned long waking = 0;
 528         int child_ready_pipe[2], go_pipe[2];
 529         const bool forks = argc > 0;
 530         char buf;
 531         struct machine *machine;
 532
 533         page_size = sysconf(_SC_PAGE_SIZE);
 534
 535         atexit(sig_atexit);
 536         signal(SIGCHLD, sig_handler);
 537         signal(SIGINT, sig_handler);
 538
 539         if (forks && (pipe(child_ready_pipe) < 0 || pipe(go_pipe) < 0)) {
 540                 perror("failed to create pipes");
 541                 exit(-1);
 542         }
 543
 544         if (!strcmp(output_name, "-"))
 545                 pipe_output = 1;
 546         else if (!stat(output_name, &st) && st.st_size) {
 547                 if (write_mode == WRITE_FORCE) {
 548                         char oldname[PATH_MAX];
 549                         snprintf(oldname, sizeof(oldname), "%s.old",
 550                                  output_name);
 551                         unlink(oldname);
 552                         rename(output_name, oldname);
 553                 }
 554         } else if (write_mode == WRITE_APPEND) {
 555                 write_mode = WRITE_FORCE;
 556         }
 557
 558         flags = O_CREAT|O_RDWR;
 559         if (write_mode == WRITE_APPEND)
 560                 file_new = 0;
 561         else
 562                 flags |= O_TRUNC;
 563
 564         if (pipe_output)
 565                 output = STDOUT_FILENO;
 566         else
 567                 output = open(output_name, flags, S_IRUSR | S_IWUSR);
 568         if (output < 0) {
 569                 perror("failed to create output file");
 570                 exit(-1);
 571         }
 572
 573         session = perf_session__new(output_name, O_WRONLY,
 574                                     write_mode == WRITE_FORCE, false);
 575         if (session == NULL) {
 576                 pr_err("Not enough memory for reading perf file header\n");
 577                 return -1;
 578         }
 579
 580         if (!no_buildid)
 581                 perf_header__set_feat(&session->header, HEADER_BUILD_ID);
 582
 583         if (!file_new) {
 584                 err = perf_header__read(session, output);
 585                 if (err < 0)
 586                         goto out_delete_session;
 587         }
 588
 589         if (have_tracepoints(attrs, nr_counters))
 590                 perf_header__set_feat(&session->header, HEADER_TRACE_INFO);
 591
 592         /*
 593          * perf_session__delete(session) will be called at atexit_header()
 594          */
 595         atexit(atexit_header);
 596
 597         if (forks) {
 598                 child_pid = fork();
 599                 if (child_pid < 0) {
 600                         perror("failed to fork");
 601                         exit(-1);
 602                 }
 603
 604                 if (!child_pid) {
 605                         if (pipe_output)
 606                                 dup2(2, 1);
 607                         close(child_ready_pipe[0]);
 608                         close(go_pipe[1]);
 609                         fcntl(go_pipe[0], F_SETFD, FD_CLOEXEC);
 610
 611                         /*
 612                          * Do a dummy execvp to get the PLT entry resolved,
 613                          * so we avoid the resolver overhead on the real
 614                          * execvp call.
 615                          */
 616                         execvp("", (char **)argv);
 617
 618                         /*
 619                          * Tell the parent we're ready to go
 620                          */
 621                         close(child_ready_pipe[1]);
 622
 623                         /*
 624                          * Wait until the parent tells us to go.
 625                          */
 626                         if (read(go_pipe[0], &buf, 1) == -1)
 627                                 perror("unable to read pipe");
 628
 629                         execvp(argv[0], (char **)argv);
 630
 631                         perror(argv[0]);
 632                         exit(-1);
 633                 }
 634
 635                 if (!system_wide && target_tid == -1 && target_pid == -1)
 636                         all_tids[0] = child_pid;
 637
 638                 close(child_ready_pipe[1]);
 639                 close(go_pipe[0]);
 640                 /*
 641                  * wait for child to settle
 642                  */
 643                 if (read(child_ready_pipe[0], &buf, 1) == -1) {
 644                         perror("unable to read pipe");
 645                         exit(-1);
 646                 }
 647                 close(child_ready_pipe[0]);
 648         }
 649
 650         nr_cpus = read_cpu_map(cpu_list);
 651         if (nr_cpus < 1) {
 652                 perror("failed to collect number of CPUs");
 653                 return -1;
 654         }
 655
 656         if (!system_wide && no_inherit && !cpu_list) {
 657                 open_counters(-1);
 658         } else {
 659                 for (i = 0; i < nr_cpus; i++)
 660                         open_counters(cpumap[i]);
 661         }
 662
 663         perf_session__set_sample_type(session, sample_type);
 664
 665         if (pipe_output) {
 666                 err = perf_header__write_pipe(output);
 667                 if (err < 0)
 668                         return err;
 669         } else if (file_new) {
 670                 err = perf_header__write(&session->header, output, false);
 671                 if (err < 0)
 672                         return err;
 673         }
 674
 675         post_processing_offset = lseek(output, 0, SEEK_CUR);
 676
 677         perf_session__set_sample_id_all(session, sample_id_all_avail);
 678
 679         if (pipe_output) {
 680                 err = event__synthesize_attrs(&session->header,
 681                                               process_synthesized_event,
 682                                               session);
 683                 if (err < 0) {
 684                         pr_err("Couldn't synthesize attrs.\n");
 685                         return err;
 686                 }
 687
 688                 err = event__synthesize_event_types(process_synthesized_event,
 689                                                     session);
 690                 if (err < 0) {
 691                         pr_err("Couldn't synthesize event_types.\n");
 692                         return err;
 693                 }
 694
 695                 if (have_tracepoints(attrs, nr_counters)) {
 696                         /*
 697                          * FIXME err <= 0 here actually means that
 698                          * there were no tracepoints so its not really
 699                          * an error, just that we don't need to
 700                          * synthesize anything.  We really have to
 701                          * return this more properly and also
 702                          * propagate errors that now are calling die()
 703                          */
 704                         err = event__synthesize_tracing_data(output, attrs,
 705                                                              nr_counters,
 706                                                              process_synthesized_event,
 707                                                              session);
 708                         if (err <= 0) {
 709                                 pr_err("Couldn't record tracing data.\n");
 710                                 return err;
 711                         }
 712                         advance_output(err);
 713                 }
 714         }
 715
 716         machine = perf_session__find_host_machine(session);
 717         if (!machine) {
 718                 pr_err("Couldn't find native kernel information.\n");
 719                 return -1;
 720         }
 721
 722         err = event__synthesize_kernel_mmap(process_synthesized_event,
 723                                             session, machine, "_text");
 724         if (err < 0)
 725                 err = event__synthesize_kernel_mmap(process_synthesized_event,
 726                                                     session, machine, "_stext");
 727         if (err < 0)
 728                 pr_err("Couldn't record kernel reference relocation symbol\n"
 729                        "Symbol resolution may be skewed if relocation was used (e.g. kexec).\n"
 730                        "Check /proc/kallsyms permission or run as root.\n");
 731
 732         err = event__synthesize_modules(process_synthesized_event,
 733                                         session, machine);
 734         if (err < 0)
 735                 pr_err("Couldn't record kernel module information.\n"
 736                        "Symbol resolution may be skewed if relocation was used (e.g. kexec).\n"
 737                        "Check /proc/modules permission or run as root.\n");
 738
 739         if (perf_guest)
 740                 perf_session__process_machines(session, event__synthesize_guest_os);
 741
 742         if (!system_wide)
 743                 event__synthesize_thread(target_tid, process_synthesized_event,
 744                                          session);
 745         else
 746                 event__synthesize_threads(process_synthesized_event, session);
 747
 748         if (realtime_prio) {
 749                 struct sched_param param;
 750
 751                 param.sched_priority = realtime_prio;
 752                 if (sched_setscheduler(0, SCHED_FIFO, &param)) {
 753                         pr_err("Could not set realtime priority.\n");
 754                         exit(-1);
 755                 }
 756         }
 757
 758         /*
 759          * Let the child rip
 760          */
 761         if (forks)
 762                 close(go_pipe[1]);
 763
 764         for (;;) {
 765                 int hits = samples;
 766                 int thread;
 767
 768                 mmap_read_all();
 769
 770                 if (hits == samples) {
 771                         if (done)
 772                                 break;
 773                         err = poll(event_array, nr_poll, -1);
 774                         waking++;
 775                 }
 776
 777                 if (done) {
 778                         for (i = 0; i < nr_cpu; i++) {
 779                                 for (counter = 0;
 780                                         counter < nr_counters;
 781                                         counter++) {
 782                                         for (thread = 0;
 783                                                 thread < thread_num;
 784                                                 thread++)
 785                                                 ioctl(fd[i][counter][thread],
 786                                                         PERF_EVENT_IOC_DISABLE);
 787                                 }
 788                         }
 789                 }
 790         }
 791
 792         if (quiet)
 793                 return 0;
 794
 795         fprintf(stderr, "[ perf record: Woken up %ld times to write data ]\n", waking);
 796
 797         /*
 798          * Approximate RIP event size: 24 bytes.
 799          */
 800         fprintf(stderr,
 801                 "[ perf record: Captured and wrote %.3f MB %s (~%lld samples) ]\n",
 802                 (double)bytes_written / 1024.0 / 1024.0,
 803                 output_name,
 804                 bytes_written / 24);
 805
 806         return 0;
 807
 808 out_delete_session:
 809         perf_session__delete(session);
 810         return err;
 811 }
 812
 813 static const char * const record_usage[] = {
 814         "perf record [<options>] [<command>]",
 815         "perf record [<options>] -- <command> [<options>]",
 816         NULL
 817 };
 818
 819 static bool force, append_file;
 820
 821 const struct option record_options[] = {
 822         OPT_CALLBACK('e', "event", NULL, "event",
 823                      "event selector. use 'perf list' to list available events",
 824                      parse_events),
 825         OPT_CALLBACK(0, "filter", NULL, "filter",
 826                      "event filter", parse_filter),
 827         OPT_INTEGER('p', "pid", &target_pid,
 828                     "record events on existing process id"),
 829         OPT_INTEGER('t', "tid", &target_tid,
 830                     "record events on existing thread id"),
 831         OPT_INTEGER('r', "realtime", &realtime_prio,
 832                     "collect data with this RT SCHED_FIFO priority"),
 833         OPT_BOOLEAN('R', "raw-samples", &raw_samples,
 834                     "collect raw sample records from all opened counters"),
 835         OPT_BOOLEAN('a', "all-cpus", &system_wide,
 836                             "system-wide collection from all CPUs"),
 837         OPT_BOOLEAN('A', "append", &append_file,
 838                             "append to the output file to do incremental profiling"),
 839         OPT_STRING('C', "cpu", &cpu_list, "cpu",
 840                     "list of cpus to monitor"),
 841         OPT_BOOLEAN('f', "force", &force,
 842                         "overwrite existing data file (deprecated)"),
 843         OPT_U64('c', "count", &user_interval, "event period to sample"),
 844         OPT_STRING('o', "output", &output_name, "file",
 845                     "output file name"),
 846         OPT_BOOLEAN('i', "no-inherit", &no_inherit,
 847                     "child tasks do not inherit counters"),
 848         OPT_UINTEGER('F', "freq", &user_freq, "profile at this frequency"),
 849         OPT_UINTEGER('m', "mmap-pages", &mmap_pages, "number of mmap data pages"),
 850         OPT_BOOLEAN('g', "call-graph", &call_graph,
 851                     "do call-graph (stack chain/backtrace) recording"),
 852         OPT_INCR('v', "verbose", &verbose,
 853                     "be more verbose (show counter open errors, etc)"),
 854         OPT_BOOLEAN('q', "quiet", &quiet, "don't print any message"),
 855         OPT_BOOLEAN('s', "stat", &inherit_stat,
 856                     "per thread counts"),
 857         OPT_BOOLEAN('d', "data", &sample_address,
 858                     "Sample addresses"),
 859         OPT_BOOLEAN('T', "timestamp", &sample_time, "Sample timestamps"),
 860         OPT_BOOLEAN('n', "no-samples", &no_samples,
 861                     "don't sample"),
 862         OPT_BOOLEAN('N', "no-buildid-cache", &no_buildid_cache,
 863                     "do not update the buildid cache"),
 864         OPT_BOOLEAN('B', "no-buildid", &no_buildid,
 865                     "do not collect buildids in perf.data"),
 866         OPT_END()
 867 };
 868
 869 int cmd_record(int argc, const char **argv, const char *prefix __used)
 870 {
 871         int i, j, err = -ENOMEM;
 872
 873         argc = parse_options(argc, argv, record_options, record_usage,
 874                             PARSE_OPT_STOP_AT_NON_OPTION);
 875         if (!argc && target_pid == -1 && target_tid == -1 &&
 876                 !system_wide && !cpu_list)
 877                 usage_with_options(record_usage, record_options);
 878
 879         if (force && append_file) {
 880                 fprintf(stderr, "Can't overwrite and append at the same time."
 881                                 " You need to choose between -f and -A");
 882                 usage_with_options(record_usage, record_options);
 883         } else if (append_file) {
 884                 write_mode = WRITE_APPEND;
 885         } else {
 886                 write_mode = WRITE_FORCE;
 887         }
 888
 889         symbol__init();
 890
 891         if (no_buildid_cache || no_buildid)
 892                 disable_buildid_cache();
 893
 894         if (!nr_counters) {
 895                 nr_counters     = 1;
 896                 attrs[0].type   = PERF_TYPE_HARDWARE;
 897                 attrs[0].config = PERF_COUNT_HW_CPU_CYCLES;
 898         }
 899
 900         if (target_pid != -1) {
 901                 target_tid = target_pid;
 902                 thread_num = find_all_tid(target_pid, &all_tids);
 903                 if (thread_num <= 0) {
 904                         fprintf(stderr, "Can't find all threads of pid %d\n",
 905                                         target_pid);
 906                         usage_with_options(record_usage, record_options);
 907                 }
 908         } else {
 909                 all_tids=malloc(sizeof(pid_t));
 910                 if (!all_tids)
 911                         goto out_symbol_exit;
 912
 913                 all_tids[0] = target_tid;
 914                 thread_num = 1;
 915         }
 916
 917         for (i = 0; i < MAX_NR_CPUS; i++) {
 918                 for (j = 0; j < MAX_COUNTERS; j++) {
 919                         fd[i][j] = malloc(sizeof(int)*thread_num);
 920                         if (!fd[i][j])
 921                                 goto out_free_fd;
 922                 }
 923         }
 924         event_array = malloc(
 925                 sizeof(struct pollfd)*MAX_NR_CPUS*MAX_COUNTERS*thread_num);
 926         if (!event_array)
 927                 goto out_free_fd;
 928
 929         if (user_interval != ULLONG_MAX)
 930                 default_interval = user_interval;
 931         if (user_freq != UINT_MAX)
 932                 freq = user_freq;
 933
 934         /*
 935          * User specified count overrides default frequency.
 936          */
 937         if (default_interval)
 938                 freq = 0;
 939         else if (freq) {
 940                 default_interval = freq;
 941         } else {
 942                 fprintf(stderr, "frequency and count are zero, aborting\n");
 943                 err = -EINVAL;
 944                 goto out_free_event_array;
 945         }
 946
 947         err = __cmd_record(argc, argv);
 948
 949 out_free_event_array:
 950         free(event_array);
 951 out_free_fd:
 952         for (i = 0; i < MAX_NR_CPUS; i++) {
 953                 for (j = 0; j < MAX_COUNTERS; j++)
 954                         free(fd[i][j]);
 955         }
 956         free(all_tids);
 957         all_tids = NULL;
 958 out_symbol_exit:
 959         symbol__exit();
 960         return err;
 961 }