tools/perf/builtin-record.c

   1 /*
   2  * builtin-record.c
   3  *
   4  * Builtin record command: Record the profile of a workload
   5  * (or a CPU, or a PID) into the perf.data output file - for
   6  * later analysis via perf report.
   7  */
   8 #include "builtin.h"
   9
  10 #include "perf.h"
  11
  12 #include "util/util.h"
  13 #include "util/parse-options.h"
  14 #include "util/parse-events.h"
  15 #include "util/string.h"
  16
  17 #include "util/header.h"
  18 #include "util/event.h"
  19 #include "util/debug.h"
  20 #include "util/session.h"
  21 #include "util/symbol.h"
  22
  23 #include <unistd.h>
  24 #include <sched.h>
  25
  26 static int                      fd[MAX_NR_CPUS][MAX_COUNTERS];
  27
  28 static long                     default_interval                =      0;
  29
  30 static int                      nr_cpus                         =      0;
  31 static unsigned int             page_size;
  32 static unsigned int             mmap_pages                      =    128;
  33 static int                      freq                            =   1000;
  34 static int                      output;
  35 static const char               *output_name                    = "perf.data";
  36 static int                      group                           =      0;
  37 static unsigned int             realtime_prio                   =      0;
  38 static int                      raw_samples                     =      0;
  39 static int                      system_wide                     =      0;
  40 static int                      profile_cpu                     =     -1;
  41 static pid_t                    target_pid                      =     -1;
  42 static pid_t                    child_pid                       =     -1;
  43 static int                      inherit                         =      1;
  44 static int                      force                           =      0;
  45 static int                      append_file                     =      0;
  46 static int                      call_graph                      =      0;
  47 static int                      inherit_stat                    =      0;
  48 static int                      no_samples                      =      0;
  49 static int                      sample_address                  =      0;
  50 static int                      multiplex                       =      0;
  51 static int                      multiplex_fd                    =     -1;
  52
  53 static long                     samples                         =      0;
  54 static struct timeval           last_read;
  55 static struct timeval           this_read;
  56
  57 static u64                      bytes_written                   =      0;
  58
  59 static struct pollfd            event_array[MAX_NR_CPUS * MAX_COUNTERS];
  60
  61 static int                      nr_poll                         =      0;
  62 static int                      nr_cpu                          =      0;
  63
  64 static int                      file_new                        =      1;
  65
  66 static struct perf_session      *session;
  67
  68 struct mmap_data {
  69         int                     counter;
  70         void                    *base;
  71         unsigned int            mask;
  72         unsigned int            prev;
  73 };
  74
  75 static struct mmap_data         mmap_array[MAX_NR_CPUS][MAX_COUNTERS];
  76
  77 static unsigned long mmap_read_head(struct mmap_data *md)
  78 {
  79         struct perf_event_mmap_page *pc = md->base;
  80         long head;
  81
  82         head = pc->data_head;
  83         rmb();
  84
  85         return head;
  86 }
  87
  88 static void mmap_write_tail(struct mmap_data *md, unsigned long tail)
  89 {
  90         struct perf_event_mmap_page *pc = md->base;
  91
  92         /*
  93          * ensure all reads are done before we write the tail out.
  94          */
  95         /* mb(); */
  96         pc->data_tail = tail;
  97 }
  98
  99 static void write_output(void *buf, size_t size)
 100 {
 101         while (size) {
 102                 int ret = write(output, buf, size);
 103
 104                 if (ret < 0)
 105                         die("failed to write");
 106
 107                 size -= ret;
 108                 buf += ret;
 109
 110                 bytes_written += ret;
 111         }
 112 }
 113
 114 static void write_event(event_t *buf, size_t size)
 115 {
 116         /*
 117         * Add it to the list of DSOs, so that when we finish this
 118          * record session we can pick the available build-ids.
 119          */
 120         if (buf->header.type == PERF_RECORD_MMAP)
 121                 dsos__findnew(buf->mmap.filename);
 122
 123         write_output(buf, size);
 124 }
 125
 126 static int process_synthesized_event(event_t *event,
 127                                      struct perf_session *self __used)
 128 {
 129         write_event(event, event->header.size);
 130         return 0;
 131 }
 132
 133 static void mmap_read(struct mmap_data *md)
 134 {
 135         unsigned int head = mmap_read_head(md);
 136         unsigned int old = md->prev;
 137         unsigned char *data = md->base + page_size;
 138         unsigned long size;
 139         void *buf;
 140         int diff;
 141
 142         gettimeofday(&this_read, NULL);
 143
 144         /*
 145          * If we're further behind than half the buffer, there's a chance
 146          * the writer will bite our tail and mess up the samples under us.
 147          *
 148          * If we somehow ended up ahead of the head, we got messed up.
 149          *
 150          * In either case, truncate and restart at head.
 151          */
 152         diff = head - old;
 153         if (diff < 0) {
 154                 struct timeval iv;
 155                 unsigned long msecs;
 156
 157                 timersub(&this_read, &last_read, &iv);
 158                 msecs = iv.tv_sec*1000 + iv.tv_usec/1000;
 159
 160                 fprintf(stderr, "WARNING: failed to keep up with mmap data."
 161                                 "  Last read %lu msecs ago.\n", msecs);
 162
 163                 /*
 164                  * head points to a known good entry, start there.
 165                  */
 166                 old = head;
 167         }
 168
 169         last_read = this_read;
 170
 171         if (old != head)
 172                 samples++;
 173
 174         size = head - old;
 175
 176         if ((old & md->mask) + size != (head & md->mask)) {
 177                 buf = &data[old & md->mask];
 178                 size = md->mask + 1 - (old & md->mask);
 179                 old += size;
 180
 181                 write_event(buf, size);
 182         }
 183
 184         buf = &data[old & md->mask];
 185         size = head - old;
 186         old += size;
 187
 188         write_event(buf, size);
 189
 190         md->prev = old;
 191         mmap_write_tail(md, old);
 192 }
 193
 194 static volatile int done = 0;
 195 static volatile int signr = -1;
 196
 197 static void sig_handler(int sig)
 198 {
 199         done = 1;
 200         signr = sig;
 201 }
 202
 203 static void sig_atexit(void)
 204 {
 205         if (child_pid != -1)
 206                 kill(child_pid, SIGTERM);
 207
 208         if (signr == -1)
 209                 return;
 210
 211         signal(signr, SIG_DFL);
 212         kill(getpid(), signr);
 213 }
 214
 215 static int group_fd;
 216
 217 static struct perf_header_attr *get_header_attr(struct perf_event_attr *a, int nr)
 218 {
 219         struct perf_header_attr *h_attr;
 220
 221         if (nr < session->header.attrs) {
 222                 h_attr = session->header.attr[nr];
 223         } else {
 224                 h_attr = perf_header_attr__new(a);
 225                 if (h_attr != NULL)
 226                         if (perf_header__add_attr(&session->header, h_attr) < 0) {
 227                                 perf_header_attr__delete(h_attr);
 228                                 h_attr = NULL;
 229                         }
 230         }
 231
 232         return h_attr;
 233 }
 234
 235 static void create_counter(int counter, int cpu, pid_t pid)
 236 {
 237         char *filter = filters[counter];
 238         struct perf_event_attr *attr = attrs + counter;
 239         struct perf_header_attr *h_attr;
 240         int track = !counter; /* only the first counter needs these */
 241         int ret;
 242         struct {
 243                 u64 count;
 244                 u64 time_enabled;
 245                 u64 time_running;
 246                 u64 id;
 247         } read_data;
 248
 249         attr->read_format       = PERF_FORMAT_TOTAL_TIME_ENABLED |
 250                                   PERF_FORMAT_TOTAL_TIME_RUNNING |
 251                                   PERF_FORMAT_ID;
 252
 253         attr->sample_type       |= PERF_SAMPLE_IP | PERF_SAMPLE_TID;
 254
 255         if (freq) {
 256                 attr->sample_type       |= PERF_SAMPLE_PERIOD;
 257                 attr->freq              = 1;
 258                 attr->sample_freq       = freq;
 259         }
 260
 261         if (no_samples)
 262                 attr->sample_freq = 0;
 263
 264         if (inherit_stat)
 265                 attr->inherit_stat = 1;
 266
 267         if (sample_address)
 268                 attr->sample_type       |= PERF_SAMPLE_ADDR;
 269
 270         if (call_graph)
 271                 attr->sample_type       |= PERF_SAMPLE_CALLCHAIN;
 272
 273         if (raw_samples) {
 274                 attr->sample_type       |= PERF_SAMPLE_TIME;
 275                 attr->sample_type       |= PERF_SAMPLE_RAW;
 276                 attr->sample_type       |= PERF_SAMPLE_CPU;
 277         }
 278
 279         attr->mmap              = track;
 280         attr->comm              = track;
 281         attr->inherit           = inherit;
 282         attr->disabled          = 1;
 283
 284 try_again:
 285         fd[nr_cpu][counter] = sys_perf_event_open(attr, pid, cpu, group_fd, 0);
 286
 287         if (fd[nr_cpu][counter] < 0) {
 288                 int err = errno;
 289
 290                 if (err == EPERM || err == EACCES)
 291                         die("Permission error - are you root?\n");
 292                 else if (err ==  ENODEV && profile_cpu != -1)
 293                         die("No such device - did you specify an out-of-range profile CPU?\n");
 294
 295                 /*
 296                  * If it's cycles then fall back to hrtimer
 297                  * based cpu-clock-tick sw counter, which
 298                  * is always available even if no PMU support:
 299                  */
 300                 if (attr->type == PERF_TYPE_HARDWARE
 301                         && attr->config == PERF_COUNT_HW_CPU_CYCLES) {
 302
 303                         if (verbose)
 304                                 warning(" ... trying to fall back to cpu-clock-ticks\n");
 305                         attr->type = PERF_TYPE_SOFTWARE;
 306                         attr->config = PERF_COUNT_SW_CPU_CLOCK;
 307                         goto try_again;
 308                 }
 309                 printf("\n");
 310                 error("perfcounter syscall returned with %d (%s)\n",
 311                         fd[nr_cpu][counter], strerror(err));
 312
 313 #if defined(__i386__) || defined(__x86_64__)
 314                 if (attr->type == PERF_TYPE_HARDWARE && err == EOPNOTSUPP)
 315                         die("No hardware sampling interrupt available. No APIC? If so then you can boot the kernel with the \"lapic\" boot parameter to force-enable it.\n");
 316 #endif
 317
 318                 die("No CONFIG_PERF_EVENTS=y kernel support configured?\n");
 319                 exit(-1);
 320         }
 321
 322         h_attr = get_header_attr(attr, counter);
 323         if (h_attr == NULL)
 324                 die("nomem\n");
 325
 326         if (!file_new) {
 327                 if (memcmp(&h_attr->attr, attr, sizeof(*attr))) {
 328                         fprintf(stderr, "incompatible append\n");
 329                         exit(-1);
 330                 }
 331         }
 332
 333         if (read(fd[nr_cpu][counter], &read_data, sizeof(read_data)) == -1) {
 334                 perror("Unable to read perf file descriptor\n");
 335                 exit(-1);
 336         }
 337
 338         if (perf_header_attr__add_id(h_attr, read_data.id) < 0) {
 339                 pr_warning("Not enough memory to add id\n");
 340                 exit(-1);
 341         }
 342
 343         assert(fd[nr_cpu][counter] >= 0);
 344         fcntl(fd[nr_cpu][counter], F_SETFL, O_NONBLOCK);
 345
 346         /*
 347          * First counter acts as the group leader:
 348          */
 349         if (group && group_fd == -1)
 350                 group_fd = fd[nr_cpu][counter];
 351         if (multiplex && multiplex_fd == -1)
 352                 multiplex_fd = fd[nr_cpu][counter];
 353
 354         if (multiplex && fd[nr_cpu][counter] != multiplex_fd) {
 355
 356                 ret = ioctl(fd[nr_cpu][counter], PERF_EVENT_IOC_SET_OUTPUT, multiplex_fd);
 357                 assert(ret != -1);
 358         } else {
 359                 event_array[nr_poll].fd = fd[nr_cpu][counter];
 360                 event_array[nr_poll].events = POLLIN;
 361                 nr_poll++;
 362
 363                 mmap_array[nr_cpu][counter].counter = counter;
 364                 mmap_array[nr_cpu][counter].prev = 0;
 365                 mmap_array[nr_cpu][counter].mask = mmap_pages*page_size - 1;
 366                 mmap_array[nr_cpu][counter].base = mmap(NULL, (mmap_pages+1)*page_size,
 367                                 PROT_READ|PROT_WRITE, MAP_SHARED, fd[nr_cpu][counter], 0);
 368                 if (mmap_array[nr_cpu][counter].base == MAP_FAILED) {
 369                         error("failed to mmap with %d (%s)\n", errno, strerror(errno));
 370                         exit(-1);
 371                 }
 372         }
 373
 374         if (filter != NULL) {
 375                 ret = ioctl(fd[nr_cpu][counter],
 376                             PERF_EVENT_IOC_SET_FILTER, filter);
 377                 if (ret) {
 378                         error("failed to set filter with %d (%s)\n", errno,
 379                               strerror(errno));
 380                         exit(-1);
 381                 }
 382         }
 383
 384         ioctl(fd[nr_cpu][counter], PERF_EVENT_IOC_ENABLE);
 385 }
 386
 387 static void open_counters(int cpu, pid_t pid)
 388 {
 389         int counter;
 390
 391         group_fd = -1;
 392         for (counter = 0; counter < nr_counters; counter++)
 393                 create_counter(counter, cpu, pid);
 394
 395         nr_cpu++;
 396 }
 397
 398 static void atexit_header(void)
 399 {
 400         session->header.data_size += bytes_written;
 401
 402         perf_header__write(&session->header, output, true);
 403 }
 404
 405 static int __cmd_record(int argc, const char **argv)
 406 {
 407         int i, counter;
 408         struct stat st;
 409         pid_t pid = 0;
 410         int flags;
 411         int err;
 412         unsigned long waking = 0;
 413         int child_ready_pipe[2], go_pipe[2];
 414         const bool forks = target_pid == -1 && argc > 0;
 415         char buf;
 416
 417         page_size = sysconf(_SC_PAGE_SIZE);
 418         nr_cpus = sysconf(_SC_NPROCESSORS_ONLN);
 419         assert(nr_cpus <= MAX_NR_CPUS);
 420         assert(nr_cpus >= 0);
 421
 422         atexit(sig_atexit);
 423         signal(SIGCHLD, sig_handler);
 424         signal(SIGINT, sig_handler);
 425
 426         if (forks && (pipe(child_ready_pipe) < 0 || pipe(go_pipe) < 0)) {
 427                 perror("failed to create pipes");
 428                 exit(-1);
 429         }
 430
 431         if (!stat(output_name, &st) && st.st_size) {
 432                 if (!force) {
 433                         if (!append_file) {
 434                                 pr_err("Error, output file %s exists, use -A "
 435                                        "to append or -f to overwrite.\n",
 436                                        output_name);
 437                                 exit(-1);
 438                         }
 439                 } else {
 440                         char oldname[PATH_MAX];
 441                         snprintf(oldname, sizeof(oldname), "%s.old",
 442                                  output_name);
 443                         unlink(oldname);
 444                         rename(output_name, oldname);
 445                 }
 446         } else {
 447                 append_file = 0;
 448         }
 449
 450         flags = O_CREAT|O_RDWR;
 451         if (append_file)
 452                 file_new = 0;
 453         else
 454                 flags |= O_TRUNC;
 455
 456         output = open(output_name, flags, S_IRUSR|S_IWUSR);
 457         if (output < 0) {
 458                 perror("failed to create output file");
 459                 exit(-1);
 460         }
 461
 462         session = perf_session__new(output_name, O_WRONLY, force);
 463         if (session == NULL) {
 464                 pr_err("Not enough memory for reading perf file header\n");
 465                 return -1;
 466         }
 467
 468         if (!file_new) {
 469                 err = perf_header__read(&session->header, output);
 470                 if (err < 0)
 471                         return err;
 472         }
 473
 474         if (raw_samples) {
 475                 perf_header__set_feat(&session->header, HEADER_TRACE_INFO);
 476         } else {
 477                 for (i = 0; i < nr_counters; i++) {
 478                         if (attrs[i].sample_type & PERF_SAMPLE_RAW) {
 479                                 perf_header__set_feat(&session->header, HEADER_TRACE_INFO);
 480                                 break;
 481                         }
 482                 }
 483         }
 484
 485         atexit(atexit_header);
 486
 487         if (forks) {
 488                 pid = fork();
 489                 if (pid < 0) {
 490                         perror("failed to fork");
 491                         exit(-1);
 492                 }
 493
 494                 if (!pid) {
 495                         close(child_ready_pipe[0]);
 496                         close(go_pipe[1]);
 497                         fcntl(go_pipe[0], F_SETFD, FD_CLOEXEC);
 498
 499                         /*
 500                          * Do a dummy execvp to get the PLT entry resolved,
 501                          * so we avoid the resolver overhead on the real
 502                          * execvp call.
 503                          */
 504                         execvp("", (char **)argv);
 505
 506                         /*
 507                          * Tell the parent we're ready to go
 508                          */
 509                         close(child_ready_pipe[1]);
 510
 511                         /*
 512                          * Wait until the parent tells us to go.
 513                          */
 514                         if (read(go_pipe[0], &buf, 1) == -1)
 515                                 perror("unable to read pipe");
 516
 517                         execvp(argv[0], (char **)argv);
 518
 519                         perror(argv[0]);
 520                         exit(-1);
 521                 }
 522
 523                 child_pid = pid;
 524
 525                 if (!system_wide)
 526                         target_pid = pid;
 527
 528                 close(child_ready_pipe[1]);
 529                 close(go_pipe[0]);
 530                 /*
 531                  * wait for child to settle
 532                  */
 533                 if (read(child_ready_pipe[0], &buf, 1) == -1) {
 534                         perror("unable to read pipe");
 535                         exit(-1);
 536                 }
 537                 close(child_ready_pipe[0]);
 538         }
 539
 540
 541         if ((!system_wide && !inherit) || profile_cpu != -1) {
 542                 open_counters(profile_cpu, target_pid);
 543         } else {
 544                 for (i = 0; i < nr_cpus; i++)
 545                         open_counters(i, target_pid);
 546         }
 547
 548         if (file_new) {
 549                 err = perf_header__write(&session->header, output, false);
 550                 if (err < 0)
 551                         return err;
 552         }
 553
 554         if (!system_wide && profile_cpu == -1)
 555                 event__synthesize_thread(pid, process_synthesized_event,
 556                                          session);
 557         else
 558                 event__synthesize_threads(process_synthesized_event, session);
 559
 560         if (realtime_prio) {
 561                 struct sched_param param;
 562
 563                 param.sched_priority = realtime_prio;
 564                 if (sched_setscheduler(0, SCHED_FIFO, &param)) {
 565                         pr_err("Could not set realtime priority.\n");
 566                         exit(-1);
 567                 }
 568         }
 569
 570         /*
 571          * Let the child rip
 572          */
 573         if (forks)
 574                 close(go_pipe[1]);
 575
 576         for (;;) {
 577                 int hits = samples;
 578
 579                 for (i = 0; i < nr_cpu; i++) {
 580                         for (counter = 0; counter < nr_counters; counter++) {
 581                                 if (mmap_array[i][counter].base)
 582                                         mmap_read(&mmap_array[i][counter]);
 583                         }
 584                 }
 585
 586                 if (hits == samples) {
 587                         if (done)
 588                                 break;
 589                         err = poll(event_array, nr_poll, -1);
 590                         waking++;
 591                 }
 592
 593                 if (done) {
 594                         for (i = 0; i < nr_cpu; i++) {
 595                                 for (counter = 0; counter < nr_counters; counter++)
 596                                         ioctl(fd[i][counter], PERF_EVENT_IOC_DISABLE);
 597                         }
 598                 }
 599         }
 600
 601         fprintf(stderr, "[ perf record: Woken up %ld times to write data ]\n", waking);
 602
 603         /*
 604          * Approximate RIP event size: 24 bytes.
 605          */
 606         fprintf(stderr,
 607                 "[ perf record: Captured and wrote %.3f MB %s (~%lld samples) ]\n",
 608                 (double)bytes_written / 1024.0 / 1024.0,
 609                 output_name,
 610                 bytes_written / 24);
 611
 612         return 0;
 613 }
 614
 615 static const char * const record_usage[] = {
 616         "perf record [<options>] [<command>]",
 617         "perf record [<options>] -- <command> [<options>]",
 618         NULL
 619 };
 620
 621 static const struct option options[] = {
 622         OPT_CALLBACK('e', "event", NULL, "event",
 623                      "event selector. use 'perf list' to list available events",
 624                      parse_events),
 625         OPT_CALLBACK(0, "filter", NULL, "filter",
 626                      "event filter", parse_filter),
 627         OPT_INTEGER('p', "pid", &target_pid,
 628                     "record events on existing pid"),
 629         OPT_INTEGER('r', "realtime", &realtime_prio,
 630                     "collect data with this RT SCHED_FIFO priority"),
 631         OPT_BOOLEAN('R', "raw-samples", &raw_samples,
 632                     "collect raw sample records from all opened counters"),
 633         OPT_BOOLEAN('a', "all-cpus", &system_wide,
 634                             "system-wide collection from all CPUs"),
 635         OPT_BOOLEAN('A', "append", &append_file,
 636                             "append to the output file to do incremental profiling"),
 637         OPT_INTEGER('C', "profile_cpu", &profile_cpu,
 638                             "CPU to profile on"),
 639         OPT_BOOLEAN('f', "force", &force,
 640                         "overwrite existing data file"),
 641         OPT_LONG('c', "count", &default_interval,
 642                     "event period to sample"),
 643         OPT_STRING('o', "output", &output_name, "file",
 644                     "output file name"),
 645         OPT_BOOLEAN('i', "inherit", &inherit,
 646                     "child tasks inherit counters"),
 647         OPT_INTEGER('F', "freq", &freq,
 648                     "profile at this frequency"),
 649         OPT_INTEGER('m', "mmap-pages", &mmap_pages,
 650                     "number of mmap data pages"),
 651         OPT_BOOLEAN('g', "call-graph", &call_graph,
 652                     "do call-graph (stack chain/backtrace) recording"),
 653         OPT_BOOLEAN('v', "verbose", &verbose,
 654                     "be more verbose (show counter open errors, etc)"),
 655         OPT_BOOLEAN('s', "stat", &inherit_stat,
 656                     "per thread counts"),
 657         OPT_BOOLEAN('d', "data", &sample_address,
 658                     "Sample addresses"),
 659         OPT_BOOLEAN('n', "no-samples", &no_samples,
 660                     "don't sample"),
 661         OPT_BOOLEAN('M', "multiplex", &multiplex,
 662                     "multiplex counter output in a single channel"),
 663         OPT_END()
 664 };
 665
 666 int cmd_record(int argc, const char **argv, const char *prefix __used)
 667 {
 668         int counter;
 669
 670         argc = parse_options(argc, argv, options, record_usage,
 671                             PARSE_OPT_STOP_AT_NON_OPTION);
 672         if (!argc && target_pid == -1 && !system_wide && profile_cpu == -1)
 673                 usage_with_options(record_usage, options);
 674
 675         symbol__init();
 676
 677         if (!nr_counters) {
 678                 nr_counters     = 1;
 679                 attrs[0].type   = PERF_TYPE_HARDWARE;
 680                 attrs[0].config = PERF_COUNT_HW_CPU_CYCLES;
 681         }
 682
 683         /*
 684          * User specified count overrides default frequency.
 685          */
 686         if (default_interval)
 687                 freq = 0;
 688         else if (freq) {
 689                 default_interval = freq;
 690         } else {
 691                 fprintf(stderr, "frequency and count are zero, aborting\n");
 692                 exit(EXIT_FAILURE);
 693         }
 694
 695         for (counter = 0; counter < nr_counters; counter++) {
 696                 if (attrs[counter].sample_period)
 697                         continue;
 698
 699                 attrs[counter].sample_period = default_interval;
 700         }
 701
 702         return __cmd_record(argc, argv);
 703 }