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/evsel.h"
  22 #include "util/debug.h"
  23 #include "util/session.h"
  24 #include "util/symbol.h"
  25 #include "util/cpumap.h"
  26
  27 #include <unistd.h>
  28 #include <sched.h>
  29 #include <sys/mman.h>
  30
  31 #define FD(e, x, y) (*(int *)xyarray__entry(e->fd, x, y))
  32
  33 enum write_mode_t {
  34         WRITE_FORCE,
  35         WRITE_APPEND
  36 };
  37
  38 static u64                      user_interval                   = ULLONG_MAX;
  39 static u64                      default_interval                =      0;
  40 static u64                      sample_type;
  41
  42 static struct cpu_map           *cpus;
  43 static unsigned int             page_size;
  44 static unsigned int             mmap_pages                      =    128;
  45 static unsigned int             user_freq                       = UINT_MAX;
  46 static int                      freq                            =   1000;
  47 static int                      output;
  48 static int                      pipe_output                     =      0;
  49 static const char               *output_name                    = "perf.data";
  50 static int                      group                           =      0;
  51 static int                      realtime_prio                   =      0;
  52 static bool                     nodelay                         =  false;
  53 static bool                     raw_samples                     =  false;
  54 static bool                     sample_id_all_avail             =   true;
  55 static bool                     system_wide                     =  false;
  56 static pid_t                    target_pid                      =     -1;
  57 static pid_t                    target_tid                      =     -1;
  58 static struct thread_map        *threads;
  59 static pid_t                    child_pid                       =     -1;
  60 static bool                     no_inherit                      =  false;
  61 static enum write_mode_t        write_mode                      = WRITE_FORCE;
  62 static bool                     call_graph                      =  false;
  63 static bool                     inherit_stat                    =  false;
  64 static bool                     no_samples                      =  false;
  65 static bool                     sample_address                  =  false;
  66 static bool                     sample_time                     =  false;
  67 static bool                     no_buildid                      =  false;
  68 static bool                     no_buildid_cache                =  false;
  69
  70 static long                     samples                         =      0;
  71 static u64                      bytes_written                   =      0;
  72
  73 static struct pollfd            *event_array;
  74
  75 static int                      nr_poll                         =      0;
  76 static int                      nr_cpu                          =      0;
  77
  78 static int                      file_new                        =      1;
  79 static off_t                    post_processing_offset;
  80
  81 static struct perf_session      *session;
  82 static const char               *cpu_list;
  83
  84 struct mmap_data {
  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 || signr == SIGUSR1)
 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(struct perf_evsel *evsel, int cpu)
 233 {
 234         char *filter = evsel->filter;
 235         struct perf_event_attr *attr = &evsel->attr;
 236         struct perf_header_attr *h_attr;
 237         int track = !evsel->idx; /* 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          * Check if parse_single_tracepoint_event has already asked for
 248          * PERF_SAMPLE_TIME.
 249          *
 250          * XXX this is kludgy but short term fix for problems introduced by
 251          * eac23d1c that broke 'perf script' by having different sample_types
 252          * when using multiple tracepoint events when we use a perf binary
 253          * that tries to use sample_id_all on an older kernel.
 254          *
 255          * We need to move counter creation to perf_session, support
 256          * different sample_types, etc.
 257          */
 258         bool time_needed = attr->sample_type & PERF_SAMPLE_TIME;
 259
 260         attr->read_format       = PERF_FORMAT_TOTAL_TIME_ENABLED |
 261                                   PERF_FORMAT_TOTAL_TIME_RUNNING |
 262                                   PERF_FORMAT_ID;
 263
 264         attr->sample_type       |= PERF_SAMPLE_IP | PERF_SAMPLE_TID;
 265
 266         if (nr_counters > 1)
 267                 attr->sample_type |= PERF_SAMPLE_ID;
 268
 269         /*
 270          * We default some events to a 1 default interval. But keep
 271          * it a weak assumption overridable by the user.
 272          */
 273         if (!attr->sample_period || (user_freq != UINT_MAX &&
 274                                      user_interval != ULLONG_MAX)) {
 275                 if (freq) {
 276                         attr->sample_type       |= PERF_SAMPLE_PERIOD;
 277                         attr->freq              = 1;
 278                         attr->sample_freq       = freq;
 279                 } else {
 280                         attr->sample_period = default_interval;
 281                 }
 282         }
 283
 284         if (no_samples)
 285                 attr->sample_freq = 0;
 286
 287         if (inherit_stat)
 288                 attr->inherit_stat = 1;
 289
 290         if (sample_address) {
 291                 attr->sample_type       |= PERF_SAMPLE_ADDR;
 292                 attr->mmap_data = track;
 293         }
 294
 295         if (call_graph)
 296                 attr->sample_type       |= PERF_SAMPLE_CALLCHAIN;
 297
 298         if (system_wide)
 299                 attr->sample_type       |= PERF_SAMPLE_CPU;
 300
 301         if (sample_id_all_avail &&
 302             (sample_time || system_wide || !no_inherit || cpu_list))
 303                 attr->sample_type       |= PERF_SAMPLE_TIME;
 304
 305         if (raw_samples) {
 306                 attr->sample_type       |= PERF_SAMPLE_TIME;
 307                 attr->sample_type       |= PERF_SAMPLE_RAW;
 308                 attr->sample_type       |= PERF_SAMPLE_CPU;
 309         }
 310
 311         if (nodelay) {
 312                 attr->watermark = 0;
 313                 attr->wakeup_events = 1;
 314         }
 315
 316         attr->mmap              = track;
 317         attr->comm              = track;
 318         attr->inherit           = !no_inherit;
 319         if (target_pid == -1 && target_tid == -1 && !system_wide) {
 320                 attr->disabled = 1;
 321                 attr->enable_on_exec = 1;
 322         }
 323 retry_sample_id:
 324         attr->sample_id_all = sample_id_all_avail ? 1 : 0;
 325
 326         for (thread_index = 0; thread_index < threads->nr; thread_index++) {
 327 try_again:
 328                 FD(evsel, nr_cpu, thread_index) = sys_perf_event_open(attr, threads->map[thread_index], cpu, group_fd, 0);
 329
 330                 if (FD(evsel, nr_cpu, thread_index) < 0) {
 331                         int err = errno;
 332
 333                         if (err == EPERM || err == EACCES)
 334                                 die("Permission error - are you root?\n"
 335                                         "\t Consider tweaking"
 336                                         " /proc/sys/kernel/perf_event_paranoid.\n");
 337                         else if (err ==  ENODEV && cpu_list) {
 338                                 die("No such device - did you specify"
 339                                         " an out-of-range profile CPU?\n");
 340                         } else if (err == EINVAL && sample_id_all_avail) {
 341                                 /*
 342                                  * Old kernel, no attr->sample_id_type_all field
 343                                  */
 344                                 sample_id_all_avail = false;
 345                                 if (!sample_time && !raw_samples && !time_needed)
 346                                         attr->sample_type &= ~PERF_SAMPLE_TIME;
 347
 348                                 goto retry_sample_id;
 349                         }
 350
 351                         /*
 352                          * If it's cycles then fall back to hrtimer
 353                          * based cpu-clock-tick sw counter, which
 354                          * is always available even if no PMU support:
 355                          */
 356                         if (attr->type == PERF_TYPE_HARDWARE
 357                                         && attr->config == PERF_COUNT_HW_CPU_CYCLES) {
 358
 359                                 if (verbose)
 360                                         warning(" ... trying to fall back to cpu-clock-ticks\n");
 361                                 attr->type = PERF_TYPE_SOFTWARE;
 362                                 attr->config = PERF_COUNT_SW_CPU_CLOCK;
 363                                 goto try_again;
 364                         }
 365                         printf("\n");
 366                         error("sys_perf_event_open() syscall returned with %d (%s).  /bin/dmesg may provide additional information.\n",
 367                               FD(evsel, nr_cpu, thread_index), strerror(err));
 368
 369 #if defined(__i386__) || defined(__x86_64__)
 370                         if (attr->type == PERF_TYPE_HARDWARE && err == EOPNOTSUPP)
 371                                 die("No hardware sampling interrupt available."
 372                                     " No APIC? If so then you can boot the kernel"
 373                                     " with the \"lapic\" boot parameter to"
 374                                     " force-enable it.\n");
 375 #endif
 376
 377                         die("No CONFIG_PERF_EVENTS=y kernel support configured?\n");
 378                         exit(-1);
 379                 }
 380
 381                 h_attr = get_header_attr(attr, evsel->idx);
 382                 if (h_attr == NULL)
 383                         die("nomem\n");
 384
 385                 if (!file_new) {
 386                         if (memcmp(&h_attr->attr, attr, sizeof(*attr))) {
 387                                 fprintf(stderr, "incompatible append\n");
 388                                 exit(-1);
 389                         }
 390                 }
 391
 392                 if (read(FD(evsel, nr_cpu, thread_index), &read_data, sizeof(read_data)) == -1) {
 393                         perror("Unable to read perf file descriptor");
 394                         exit(-1);
 395                 }
 396
 397                 if (perf_header_attr__add_id(h_attr, read_data.id) < 0) {
 398                         pr_warning("Not enough memory to add id\n");
 399                         exit(-1);
 400                 }
 401
 402                 assert(FD(evsel, nr_cpu, thread_index) >= 0);
 403                 fcntl(FD(evsel, nr_cpu, thread_index), F_SETFL, O_NONBLOCK);
 404
 405                 /*
 406                  * First counter acts as the group leader:
 407                  */
 408                 if (group && group_fd == -1)
 409                         group_fd = FD(evsel, nr_cpu, thread_index);
 410
 411                 if (evsel->idx || thread_index) {
 412                         struct perf_evsel *first;
 413                         first = list_entry(evsel_list.next, struct perf_evsel, node);
 414                         ret = ioctl(FD(evsel, nr_cpu, thread_index),
 415                                     PERF_EVENT_IOC_SET_OUTPUT,
 416                                     FD(first, nr_cpu, 0));
 417                         if (ret) {
 418                                 error("failed to set output: %d (%s)\n", errno,
 419                                                 strerror(errno));
 420                                 exit(-1);
 421                         }
 422                 } else {
 423                         mmap_array[nr_cpu].prev = 0;
 424                         mmap_array[nr_cpu].mask = mmap_pages*page_size - 1;
 425                         mmap_array[nr_cpu].base = mmap(NULL, (mmap_pages+1)*page_size,
 426                                 PROT_READ | PROT_WRITE, MAP_SHARED, FD(evsel, nr_cpu, thread_index), 0);
 427                         if (mmap_array[nr_cpu].base == MAP_FAILED) {
 428                                 error("failed to mmap with %d (%s)\n", errno, strerror(errno));
 429                                 exit(-1);
 430                         }
 431
 432                         event_array[nr_poll].fd = FD(evsel, nr_cpu, thread_index);
 433                         event_array[nr_poll].events = POLLIN;
 434                         nr_poll++;
 435                 }
 436
 437                 if (filter != NULL) {
 438                         ret = ioctl(FD(evsel, nr_cpu, thread_index),
 439                                     PERF_EVENT_IOC_SET_FILTER, filter);
 440                         if (ret) {
 441                                 error("failed to set filter with %d (%s)\n", errno,
 442                                                 strerror(errno));
 443                                 exit(-1);
 444                         }
 445                 }
 446         }
 447
 448         if (!sample_type)
 449                 sample_type = attr->sample_type;
 450 }
 451
 452 static void open_counters(int cpu)
 453 {
 454         struct perf_evsel *pos;
 455
 456         group_fd = -1;
 457
 458         list_for_each_entry(pos, &evsel_list, node)
 459                 create_counter(pos, cpu);
 460
 461         nr_cpu++;
 462 }
 463
 464 static int process_buildids(void)
 465 {
 466         u64 size = lseek(output, 0, SEEK_CUR);
 467
 468         if (size == 0)
 469                 return 0;
 470
 471         session->fd = output;
 472         return __perf_session__process_events(session, post_processing_offset,
 473                                               size - post_processing_offset,
 474                                               size, &build_id__mark_dso_hit_ops);
 475 }
 476
 477 static void atexit_header(void)
 478 {
 479         if (!pipe_output) {
 480                 session->header.data_size += bytes_written;
 481
 482                 if (!no_buildid)
 483                         process_buildids();
 484                 perf_header__write(&session->header, output, true);
 485                 perf_session__delete(session);
 486                 perf_evsel_list__delete();
 487                 symbol__exit();
 488         }
 489 }
 490
 491 static void event__synthesize_guest_os(struct machine *machine, void *data)
 492 {
 493         int err;
 494         struct perf_session *psession = data;
 495
 496         if (machine__is_host(machine))
 497                 return;
 498
 499         /*
 500          *As for guest kernel when processing subcommand record&report,
 501          *we arrange module mmap prior to guest kernel mmap and trigger
 502          *a preload dso because default guest module symbols are loaded
 503          *from guest kallsyms instead of /lib/modules/XXX/XXX. This
 504          *method is used to avoid symbol missing when the first addr is
 505          *in module instead of in guest kernel.
 506          */
 507         err = event__synthesize_modules(process_synthesized_event,
 508                                         psession, machine);
 509         if (err < 0)
 510                 pr_err("Couldn't record guest kernel [%d]'s reference"
 511                        " relocation symbol.\n", machine->pid);
 512
 513         /*
 514          * We use _stext for guest kernel because guest kernel's /proc/kallsyms
 515          * have no _text sometimes.
 516          */
 517         err = event__synthesize_kernel_mmap(process_synthesized_event,
 518                                             psession, machine, "_text");
 519         if (err < 0)
 520                 err = event__synthesize_kernel_mmap(process_synthesized_event,
 521                                                     psession, machine, "_stext");
 522         if (err < 0)
 523                 pr_err("Couldn't record guest kernel [%d]'s reference"
 524                        " relocation symbol.\n", machine->pid);
 525 }
 526
 527 static struct perf_event_header finished_round_event = {
 528         .size = sizeof(struct perf_event_header),
 529         .type = PERF_RECORD_FINISHED_ROUND,
 530 };
 531
 532 static void mmap_read_all(void)
 533 {
 534         int i;
 535
 536         for (i = 0; i < nr_cpu; i++) {
 537                 if (mmap_array[i].base)
 538                         mmap_read(&mmap_array[i]);
 539         }
 540
 541         if (perf_header__has_feat(&session->header, HEADER_TRACE_INFO))
 542                 write_output(&finished_round_event, sizeof(finished_round_event));
 543 }
 544
 545 static int __cmd_record(int argc, const char **argv)
 546 {
 547         int i;
 548         struct stat st;
 549         int flags;
 550         int err;
 551         unsigned long waking = 0;
 552         int child_ready_pipe[2], go_pipe[2];
 553         const bool forks = argc > 0;
 554         char buf;
 555         struct machine *machine;
 556
 557         page_size = sysconf(_SC_PAGE_SIZE);
 558
 559         atexit(sig_atexit);
 560         signal(SIGCHLD, sig_handler);
 561         signal(SIGINT, sig_handler);
 562         signal(SIGUSR1, sig_handler);
 563
 564         if (forks && (pipe(child_ready_pipe) < 0 || pipe(go_pipe) < 0)) {
 565                 perror("failed to create pipes");
 566                 exit(-1);
 567         }
 568
 569         if (!strcmp(output_name, "-"))
 570                 pipe_output = 1;
 571         else if (!stat(output_name, &st) && st.st_size) {
 572                 if (write_mode == WRITE_FORCE) {
 573                         char oldname[PATH_MAX];
 574                         snprintf(oldname, sizeof(oldname), "%s.old",
 575                                  output_name);
 576                         unlink(oldname);
 577                         rename(output_name, oldname);
 578                 }
 579         } else if (write_mode == WRITE_APPEND) {
 580                 write_mode = WRITE_FORCE;
 581         }
 582
 583         flags = O_CREAT|O_RDWR;
 584         if (write_mode == WRITE_APPEND)
 585                 file_new = 0;
 586         else
 587                 flags |= O_TRUNC;
 588
 589         if (pipe_output)
 590                 output = STDOUT_FILENO;
 591         else
 592                 output = open(output_name, flags, S_IRUSR | S_IWUSR);
 593         if (output < 0) {
 594                 perror("failed to create output file");
 595                 exit(-1);
 596         }
 597
 598         session = perf_session__new(output_name, O_WRONLY,
 599                                     write_mode == WRITE_FORCE, false, NULL);
 600         if (session == NULL) {
 601                 pr_err("Not enough memory for reading perf file header\n");
 602                 return -1;
 603         }
 604
 605         if (!no_buildid)
 606                 perf_header__set_feat(&session->header, HEADER_BUILD_ID);
 607
 608         if (!file_new) {
 609                 err = perf_header__read(session, output);
 610                 if (err < 0)
 611                         goto out_delete_session;
 612         }
 613
 614         if (have_tracepoints(&evsel_list))
 615                 perf_header__set_feat(&session->header, HEADER_TRACE_INFO);
 616
 617         /*
 618          * perf_session__delete(session) will be called at atexit_header()
 619          */
 620         atexit(atexit_header);
 621
 622         if (forks) {
 623                 child_pid = fork();
 624                 if (child_pid < 0) {
 625                         perror("failed to fork");
 626                         exit(-1);
 627                 }
 628
 629                 if (!child_pid) {
 630                         if (pipe_output)
 631                                 dup2(2, 1);
 632                         close(child_ready_pipe[0]);
 633                         close(go_pipe[1]);
 634                         fcntl(go_pipe[0], F_SETFD, FD_CLOEXEC);
 635
 636                         /*
 637                          * Do a dummy execvp to get the PLT entry resolved,
 638                          * so we avoid the resolver overhead on the real
 639                          * execvp call.
 640                          */
 641                         execvp("", (char **)argv);
 642
 643                         /*
 644                          * Tell the parent we're ready to go
 645                          */
 646                         close(child_ready_pipe[1]);
 647
 648                         /*
 649                          * Wait until the parent tells us to go.
 650                          */
 651                         if (read(go_pipe[0], &buf, 1) == -1)
 652                                 perror("unable to read pipe");
 653
 654                         execvp(argv[0], (char **)argv);
 655
 656                         perror(argv[0]);
 657                         kill(getppid(), SIGUSR1);
 658                         exit(-1);
 659                 }
 660
 661                 if (!system_wide && target_tid == -1 && target_pid == -1)
 662                         threads->map[0] = child_pid;
 663
 664                 close(child_ready_pipe[1]);
 665                 close(go_pipe[0]);
 666                 /*
 667                  * wait for child to settle
 668                  */
 669                 if (read(child_ready_pipe[0], &buf, 1) == -1) {
 670                         perror("unable to read pipe");
 671                         exit(-1);
 672                 }
 673                 close(child_ready_pipe[0]);
 674         }
 675
 676         if (!system_wide && no_inherit && !cpu_list) {
 677                 open_counters(-1);
 678         } else {
 679                 for (i = 0; i < cpus->nr; i++)
 680                         open_counters(cpus->map[i]);
 681         }
 682
 683         perf_session__set_sample_type(session, sample_type);
 684
 685         if (pipe_output) {
 686                 err = perf_header__write_pipe(output);
 687                 if (err < 0)
 688                         return err;
 689         } else if (file_new) {
 690                 err = perf_header__write(&session->header, output, false);
 691                 if (err < 0)
 692                         return err;
 693         }
 694
 695         post_processing_offset = lseek(output, 0, SEEK_CUR);
 696
 697         perf_session__set_sample_id_all(session, sample_id_all_avail);
 698
 699         if (pipe_output) {
 700                 err = event__synthesize_attrs(&session->header,
 701                                               process_synthesized_event,
 702                                               session);
 703                 if (err < 0) {
 704                         pr_err("Couldn't synthesize attrs.\n");
 705                         return err;
 706                 }
 707
 708                 err = event__synthesize_event_types(process_synthesized_event,
 709                                                     session);
 710                 if (err < 0) {
 711                         pr_err("Couldn't synthesize event_types.\n");
 712                         return err;
 713                 }
 714
 715                 if (have_tracepoints(&evsel_list)) {
 716                         /*
 717                          * FIXME err <= 0 here actually means that
 718                          * there were no tracepoints so its not really
 719                          * an error, just that we don't need to
 720                          * synthesize anything.  We really have to
 721                          * return this more properly and also
 722                          * propagate errors that now are calling die()
 723                          */
 724                         err = event__synthesize_tracing_data(output, &evsel_list,
 725                                                              process_synthesized_event,
 726                                                              session);
 727                         if (err <= 0) {
 728                                 pr_err("Couldn't record tracing data.\n");
 729                                 return err;
 730                         }
 731                         advance_output(err);
 732                 }
 733         }
 734
 735         machine = perf_session__find_host_machine(session);
 736         if (!machine) {
 737                 pr_err("Couldn't find native kernel information.\n");
 738                 return -1;
 739         }
 740
 741         err = event__synthesize_kernel_mmap(process_synthesized_event,
 742                                             session, machine, "_text");
 743         if (err < 0)
 744                 err = event__synthesize_kernel_mmap(process_synthesized_event,
 745                                                     session, machine, "_stext");
 746         if (err < 0)
 747                 pr_err("Couldn't record kernel reference relocation symbol\n"
 748                        "Symbol resolution may be skewed if relocation was used (e.g. kexec).\n"
 749                        "Check /proc/kallsyms permission or run as root.\n");
 750
 751         err = event__synthesize_modules(process_synthesized_event,
 752                                         session, machine);
 753         if (err < 0)
 754                 pr_err("Couldn't record kernel module information.\n"
 755                        "Symbol resolution may be skewed if relocation was used (e.g. kexec).\n"
 756                        "Check /proc/modules permission or run as root.\n");
 757
 758         if (perf_guest)
 759                 perf_session__process_machines(session, event__synthesize_guest_os);
 760
 761         if (!system_wide)
 762                 event__synthesize_thread_map(threads, process_synthesized_event,
 763                                              session);
 764         else
 765                 event__synthesize_threads(process_synthesized_event, session);
 766
 767         if (realtime_prio) {
 768                 struct sched_param param;
 769
 770                 param.sched_priority = realtime_prio;
 771                 if (sched_setscheduler(0, SCHED_FIFO, &param)) {
 772                         pr_err("Could not set realtime priority.\n");
 773                         exit(-1);
 774                 }
 775         }
 776
 777         /*
 778          * Let the child rip
 779          */
 780         if (forks)
 781                 close(go_pipe[1]);
 782
 783         for (;;) {
 784                 int hits = samples;
 785                 int thread;
 786
 787                 mmap_read_all();
 788
 789                 if (hits == samples) {
 790                         if (done)
 791                                 break;
 792                         err = poll(event_array, nr_poll, -1);
 793                         waking++;
 794                 }
 795
 796                 if (done) {
 797                         for (i = 0; i < nr_cpu; i++) {
 798                                 struct perf_evsel *pos;
 799
 800                                 list_for_each_entry(pos, &evsel_list, node) {
 801                                         for (thread = 0;
 802                                                 thread < threads->nr;
 803                                                 thread++)
 804                                                 ioctl(FD(pos, i, thread),
 805                                                         PERF_EVENT_IOC_DISABLE);
 806                                 }
 807                         }
 808                 }
 809         }
 810
 811         if (quiet || signr == SIGUSR1)
 812                 return 0;
 813
 814         fprintf(stderr, "[ perf record: Woken up %ld times to write data ]\n", waking);
 815
 816         /*
 817          * Approximate RIP event size: 24 bytes.
 818          */
 819         fprintf(stderr,
 820                 "[ perf record: Captured and wrote %.3f MB %s (~%" PRIu64 " samples) ]\n",
 821                 (double)bytes_written / 1024.0 / 1024.0,
 822                 output_name,
 823                 bytes_written / 24);
 824
 825         return 0;
 826
 827 out_delete_session:
 828         perf_session__delete(session);
 829         return err;
 830 }
 831
 832 static const char * const record_usage[] = {
 833         "perf record [<options>] [<command>]",
 834         "perf record [<options>] -- <command> [<options>]",
 835         NULL
 836 };
 837
 838 static bool force, append_file;
 839
 840 const struct option record_options[] = {
 841         OPT_CALLBACK('e', "event", NULL, "event",
 842                      "event selector. use 'perf list' to list available events",
 843                      parse_events),
 844         OPT_CALLBACK(0, "filter", NULL, "filter",
 845                      "event filter", parse_filter),
 846         OPT_INTEGER('p', "pid", &target_pid,
 847                     "record events on existing process id"),
 848         OPT_INTEGER('t', "tid", &target_tid,
 849                     "record events on existing thread id"),
 850         OPT_INTEGER('r', "realtime", &realtime_prio,
 851                     "collect data with this RT SCHED_FIFO priority"),
 852         OPT_BOOLEAN('D', "no-delay", &nodelay,
 853                     "collect data without buffering"),
 854         OPT_BOOLEAN('R', "raw-samples", &raw_samples,
 855                     "collect raw sample records from all opened counters"),
 856         OPT_BOOLEAN('a', "all-cpus", &system_wide,
 857                             "system-wide collection from all CPUs"),
 858         OPT_BOOLEAN('A', "append", &append_file,
 859                             "append to the output file to do incremental profiling"),
 860         OPT_STRING('C', "cpu", &cpu_list, "cpu",
 861                     "list of cpus to monitor"),
 862         OPT_BOOLEAN('f', "force", &force,
 863                         "overwrite existing data file (deprecated)"),
 864         OPT_U64('c', "count", &user_interval, "event period to sample"),
 865         OPT_STRING('o', "output", &output_name, "file",
 866                     "output file name"),
 867         OPT_BOOLEAN('i', "no-inherit", &no_inherit,
 868                     "child tasks do not inherit counters"),
 869         OPT_UINTEGER('F', "freq", &user_freq, "profile at this frequency"),
 870         OPT_UINTEGER('m', "mmap-pages", &mmap_pages, "number of mmap data pages"),
 871         OPT_BOOLEAN('g', "call-graph", &call_graph,
 872                     "do call-graph (stack chain/backtrace) recording"),
 873         OPT_INCR('v', "verbose", &verbose,
 874                     "be more verbose (show counter open errors, etc)"),
 875         OPT_BOOLEAN('q', "quiet", &quiet, "don't print any message"),
 876         OPT_BOOLEAN('s', "stat", &inherit_stat,
 877                     "per thread counts"),
 878         OPT_BOOLEAN('d', "data", &sample_address,
 879                     "Sample addresses"),
 880         OPT_BOOLEAN('T', "timestamp", &sample_time, "Sample timestamps"),
 881         OPT_BOOLEAN('n', "no-samples", &no_samples,
 882                     "don't sample"),
 883         OPT_BOOLEAN('N', "no-buildid-cache", &no_buildid_cache,
 884                     "do not update the buildid cache"),
 885         OPT_BOOLEAN('B', "no-buildid", &no_buildid,
 886                     "do not collect buildids in perf.data"),
 887         OPT_END()
 888 };
 889
 890 int cmd_record(int argc, const char **argv, const char *prefix __used)
 891 {
 892         int err = -ENOMEM;
 893         struct perf_evsel *pos;
 894
 895         argc = parse_options(argc, argv, record_options, record_usage,
 896                             PARSE_OPT_STOP_AT_NON_OPTION);
 897         if (!argc && target_pid == -1 && target_tid == -1 &&
 898                 !system_wide && !cpu_list)
 899                 usage_with_options(record_usage, record_options);
 900
 901         if (force && append_file) {
 902                 fprintf(stderr, "Can't overwrite and append at the same time."
 903                                 " You need to choose between -f and -A");
 904                 usage_with_options(record_usage, record_options);
 905         } else if (append_file) {
 906                 write_mode = WRITE_APPEND;
 907         } else {
 908                 write_mode = WRITE_FORCE;
 909         }
 910
 911         symbol__init();
 912
 913         if (no_buildid_cache || no_buildid)
 914                 disable_buildid_cache();
 915
 916         if (list_empty(&evsel_list) && perf_evsel_list__create_default() < 0) {
 917                 pr_err("Not enough memory for event selector list\n");
 918                 goto out_symbol_exit;
 919         }
 920
 921         if (target_pid != -1)
 922                 target_tid = target_pid;
 923
 924         threads = thread_map__new(target_pid, target_tid);
 925         if (threads == NULL) {
 926                 pr_err("Problems finding threads of monitor\n");
 927                 usage_with_options(record_usage, record_options);
 928         }
 929
 930         cpus = cpu_map__new(cpu_list);
 931         if (cpus == NULL) {
 932                 perror("failed to parse CPUs map");
 933                 return -1;
 934         }
 935
 936         list_for_each_entry(pos, &evsel_list, node) {
 937                 if (perf_evsel__alloc_fd(pos, cpus->nr, threads->nr) < 0)
 938                         goto out_free_fd;
 939                 if (perf_header__push_event(pos->attr.config, event_name(pos)))
 940                         goto out_free_fd;
 941         }
 942         event_array = malloc((sizeof(struct pollfd) * MAX_NR_CPUS *
 943                               MAX_COUNTERS * threads->nr));
 944         if (!event_array)
 945                 goto out_free_fd;
 946
 947         if (user_interval != ULLONG_MAX)
 948                 default_interval = user_interval;
 949         if (user_freq != UINT_MAX)
 950                 freq = user_freq;
 951
 952         /*
 953          * User specified count overrides default frequency.
 954          */
 955         if (default_interval)
 956                 freq = 0;
 957         else if (freq) {
 958                 default_interval = freq;
 959         } else {
 960                 fprintf(stderr, "frequency and count are zero, aborting\n");
 961                 err = -EINVAL;
 962                 goto out_free_event_array;
 963         }
 964
 965         err = __cmd_record(argc, argv);
 966
 967 out_free_event_array:
 968         free(event_array);
 969 out_free_fd:
 970         thread_map__delete(threads);
 971         threads = NULL;
 972 out_symbol_exit:
 973         symbol__exit();
 974         return err;
 975 }