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