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 #include "util/string.h"
  19
  20 #include "util/header.h"
  21 #include "util/event.h"
  22 #include "util/debug.h"
  23 #include "util/session.h"
  24 #include "util/symbol.h"
  25
  26 #include <unistd.h>
  27 #include <sched.h>
  28
  29 static int                      fd[MAX_NR_CPUS][MAX_COUNTERS];
  30
  31 static long                     default_interval                =      0;
  32
  33 static int                      nr_cpus                         =      0;
  34 static unsigned int             page_size;
  35 static unsigned int             mmap_pages                      =    128;
  36 static int                      freq                            =   1000;
  37 static int                      output;
  38 static const char               *output_name                    = "perf.data";
  39 static int                      group                           =      0;
  40 static unsigned int             realtime_prio                   =      0;
  41 static int                      raw_samples                     =      0;
  42 static int                      system_wide                     =      0;
  43 static int                      profile_cpu                     =     -1;
  44 static pid_t                    target_pid                      =     -1;
  45 static pid_t                    child_pid                       =     -1;
  46 static int                      inherit                         =      1;
  47 static int                      force                           =      0;
  48 static int                      append_file                     =      0;
  49 static int                      call_graph                      =      0;
  50 static int                      inherit_stat                    =      0;
  51 static int                      no_samples                      =      0;
  52 static int                      sample_address                  =      0;
  53 static int                      multiplex                       =      0;
  54 static int                      multiplex_fd                    =     -1;
  55
  56 static long                     samples                         =      0;
  57 static struct timeval           last_read;
  58 static struct timeval           this_read;
  59
  60 static u64                      bytes_written                   =      0;
  61
  62 static struct pollfd            event_array[MAX_NR_CPUS * MAX_COUNTERS];
  63
  64 static int                      nr_poll                         =      0;
  65 static int                      nr_cpu                          =      0;
  66
  67 static int                      file_new                        =      1;
  68 static off_t                    post_processing_offset;
  69
  70 static struct perf_session      *session;
  71
  72 struct mmap_data {
  73         int                     counter;
  74         void                    *base;
  75         unsigned int            mask;
  76         unsigned int            prev;
  77 };
  78
  79 static struct mmap_data         mmap_array[MAX_NR_CPUS][MAX_COUNTERS];
  80
  81 static unsigned long mmap_read_head(struct mmap_data *md)
  82 {
  83         struct perf_event_mmap_page *pc = md->base;
  84         long head;
  85
  86         head = pc->data_head;
  87         rmb();
  88
  89         return head;
  90 }
  91
  92 static void mmap_write_tail(struct mmap_data *md, unsigned long tail)
  93 {
  94         struct perf_event_mmap_page *pc = md->base;
  95
  96         /*
  97          * ensure all reads are done before we write the tail out.
  98          */
  99         /* mb(); */
 100         pc->data_tail = tail;
 101 }
 102
 103 static void write_output(void *buf, size_t size)
 104 {
 105         while (size) {
 106                 int ret = write(output, buf, size);
 107
 108                 if (ret < 0)
 109                         die("failed to write");
 110
 111                 size -= ret;
 112                 buf += ret;
 113
 114                 bytes_written += ret;
 115         }
 116 }
 117
 118 static int process_synthesized_event(event_t *event,
 119                                      struct perf_session *self __used)
 120 {
 121         write_output(event, event->header.size);
 122         return 0;
 123 }
 124
 125 static void mmap_read(struct mmap_data *md)
 126 {
 127         unsigned int head = mmap_read_head(md);
 128         unsigned int old = md->prev;
 129         unsigned char *data = md->base + page_size;
 130         unsigned long size;
 131         void *buf;
 132         int diff;
 133
 134         gettimeofday(&this_read, NULL);
 135
 136         /*
 137          * If we're further behind than half the buffer, there's a chance
 138          * the writer will bite our tail and mess up the samples under us.
 139          *
 140          * If we somehow ended up ahead of the head, we got messed up.
 141          *
 142          * In either case, truncate and restart at head.
 143          */
 144         diff = head - old;
 145         if (diff < 0) {
 146                 struct timeval iv;
 147                 unsigned long msecs;
 148
 149                 timersub(&this_read, &last_read, &iv);
 150                 msecs = iv.tv_sec*1000 + iv.tv_usec/1000;
 151
 152                 fprintf(stderr, "WARNING: failed to keep up with mmap data."
 153                                 "  Last read %lu msecs ago.\n", msecs);
 154
 155                 /*
 156                  * head points to a known good entry, start there.
 157                  */
 158                 old = head;
 159         }
 160
 161         last_read = this_read;
 162
 163         if (old != head)
 164                 samples++;
 165
 166         size = head - old;
 167
 168         if ((old & md->mask) + size != (head & md->mask)) {
 169                 buf = &data[old & md->mask];
 170                 size = md->mask + 1 - (old & md->mask);
 171                 old += size;
 172
 173                 write_output(buf, size);
 174         }
 175
 176         buf = &data[old & md->mask];
 177         size = head - old;
 178         old += size;
 179
 180         write_output(buf, size);
 181
 182         md->prev = old;
 183         mmap_write_tail(md, old);
 184 }
 185
 186 static volatile int done = 0;
 187 static volatile int signr = -1;
 188
 189 static void sig_handler(int sig)
 190 {
 191         done = 1;
 192         signr = sig;
 193 }
 194
 195 static void sig_atexit(void)
 196 {
 197         if (child_pid != -1)
 198                 kill(child_pid, SIGTERM);
 199
 200         if (signr == -1)
 201                 return;
 202
 203         signal(signr, SIG_DFL);
 204         kill(getpid(), signr);
 205 }
 206
 207 static int group_fd;
 208
 209 static struct perf_header_attr *get_header_attr(struct perf_event_attr *a, int nr)
 210 {
 211         struct perf_header_attr *h_attr;
 212
 213         if (nr < session->header.attrs) {
 214                 h_attr = session->header.attr[nr];
 215         } else {
 216                 h_attr = perf_header_attr__new(a);
 217                 if (h_attr != NULL)
 218                         if (perf_header__add_attr(&session->header, h_attr) < 0) {
 219                                 perf_header_attr__delete(h_attr);
 220                                 h_attr = NULL;
 221                         }
 222         }
 223
 224         return h_attr;
 225 }
 226
 227 static void create_counter(int counter, int cpu, pid_t pid)
 228 {
 229         char *filter = filters[counter];
 230         struct perf_event_attr *attr = attrs + counter;
 231         struct perf_header_attr *h_attr;
 232         int track = !counter; /* only the first counter needs these */
 233         int ret;
 234         struct {
 235                 u64 count;
 236                 u64 time_enabled;
 237                 u64 time_running;
 238                 u64 id;
 239         } read_data;
 240
 241         attr->read_format       = PERF_FORMAT_TOTAL_TIME_ENABLED |
 242                                   PERF_FORMAT_TOTAL_TIME_RUNNING |
 243                                   PERF_FORMAT_ID;
 244
 245         attr->sample_type       |= PERF_SAMPLE_IP | PERF_SAMPLE_TID;
 246
 247         if (nr_counters > 1)
 248                 attr->sample_type |= PERF_SAMPLE_ID;
 249
 250         if (freq) {
 251                 attr->sample_type       |= PERF_SAMPLE_PERIOD;
 252                 attr->freq              = 1;
 253                 attr->sample_freq       = freq;
 254         }
 255
 256         if (no_samples)
 257                 attr->sample_freq = 0;
 258
 259         if (inherit_stat)
 260                 attr->inherit_stat = 1;
 261
 262         if (sample_address)
 263                 attr->sample_type       |= PERF_SAMPLE_ADDR;
 264
 265         if (call_graph)
 266                 attr->sample_type       |= PERF_SAMPLE_CALLCHAIN;
 267
 268         if (raw_samples) {
 269                 attr->sample_type       |= PERF_SAMPLE_TIME;
 270                 attr->sample_type       |= PERF_SAMPLE_RAW;
 271                 attr->sample_type       |= PERF_SAMPLE_CPU;
 272         }
 273
 274         attr->mmap              = track;
 275         attr->comm              = track;
 276         attr->inherit           = inherit;
 277         attr->disabled          = 1;
 278
 279 try_again:
 280         fd[nr_cpu][counter] = sys_perf_event_open(attr, pid, cpu, group_fd, 0);
 281
 282         if (fd[nr_cpu][counter] < 0) {
 283                 int err = errno;
 284
 285                 if (err == EPERM || err == EACCES)
 286                         die("Permission error - are you root?\n");
 287                 else if (err ==  ENODEV && profile_cpu != -1)
 288                         die("No such device - did you specify an out-of-range profile CPU?\n");
 289
 290                 /*
 291                  * If it's cycles then fall back to hrtimer
 292                  * based cpu-clock-tick sw counter, which
 293                  * is always available even if no PMU support:
 294                  */
 295                 if (attr->type == PERF_TYPE_HARDWARE
 296                         && attr->config == PERF_COUNT_HW_CPU_CYCLES) {
 297
 298                         if (verbose)
 299                                 warning(" ... trying to fall back to cpu-clock-ticks\n");
 300                         attr->type = PERF_TYPE_SOFTWARE;
 301                         attr->config = PERF_COUNT_SW_CPU_CLOCK;
 302                         goto try_again;
 303                 }
 304                 printf("\n");
 305                 error("perfcounter syscall returned with %d (%s)\n",
 306                         fd[nr_cpu][counter], strerror(err));
 307
 308 #if defined(__i386__) || defined(__x86_64__)
 309                 if (attr->type == PERF_TYPE_HARDWARE && err == EOPNOTSUPP)
 310                         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");
 311 #endif
 312
 313                 die("No CONFIG_PERF_EVENTS=y kernel support configured?\n");
 314                 exit(-1);
 315         }
 316
 317         h_attr = get_header_attr(attr, counter);
 318         if (h_attr == NULL)
 319                 die("nomem\n");
 320
 321         if (!file_new) {
 322                 if (memcmp(&h_attr->attr, attr, sizeof(*attr))) {
 323                         fprintf(stderr, "incompatible append\n");
 324                         exit(-1);
 325                 }
 326         }
 327
 328         if (read(fd[nr_cpu][counter], &read_data, sizeof(read_data)) == -1) {
 329                 perror("Unable to read perf file descriptor\n");
 330                 exit(-1);
 331         }
 332
 333         if (perf_header_attr__add_id(h_attr, read_data.id) < 0) {
 334                 pr_warning("Not enough memory to add id\n");
 335                 exit(-1);
 336         }
 337
 338         assert(fd[nr_cpu][counter] >= 0);
 339         fcntl(fd[nr_cpu][counter], F_SETFL, O_NONBLOCK);
 340
 341         /*
 342          * First counter acts as the group leader:
 343          */
 344         if (group && group_fd == -1)
 345                 group_fd = fd[nr_cpu][counter];
 346         if (multiplex && multiplex_fd == -1)
 347                 multiplex_fd = fd[nr_cpu][counter];
 348
 349         if (multiplex && fd[nr_cpu][counter] != multiplex_fd) {
 350
 351                 ret = ioctl(fd[nr_cpu][counter], PERF_EVENT_IOC_SET_OUTPUT, multiplex_fd);
 352                 assert(ret != -1);
 353         } else {
 354                 event_array[nr_poll].fd = fd[nr_cpu][counter];
 355                 event_array[nr_poll].events = POLLIN;
 356                 nr_poll++;
 357
 358                 mmap_array[nr_cpu][counter].counter = counter;
 359                 mmap_array[nr_cpu][counter].prev = 0;
 360                 mmap_array[nr_cpu][counter].mask = mmap_pages*page_size - 1;
 361                 mmap_array[nr_cpu][counter].base = mmap(NULL, (mmap_pages+1)*page_size,
 362                                 PROT_READ|PROT_WRITE, MAP_SHARED, fd[nr_cpu][counter], 0);
 363                 if (mmap_array[nr_cpu][counter].base == MAP_FAILED) {
 364                         error("failed to mmap with %d (%s)\n", errno, strerror(errno));
 365                         exit(-1);
 366                 }
 367         }
 368
 369         if (filter != NULL) {
 370                 ret = ioctl(fd[nr_cpu][counter],
 371                             PERF_EVENT_IOC_SET_FILTER, filter);
 372                 if (ret) {
 373                         error("failed to set filter with %d (%s)\n", errno,
 374                               strerror(errno));
 375                         exit(-1);
 376                 }
 377         }
 378
 379         ioctl(fd[nr_cpu][counter], PERF_EVENT_IOC_ENABLE);
 380 }
 381
 382 static void open_counters(int cpu, pid_t pid)
 383 {
 384         int counter;
 385
 386         group_fd = -1;
 387         for (counter = 0; counter < nr_counters; counter++)
 388                 create_counter(counter, cpu, pid);
 389
 390         nr_cpu++;
 391 }
 392
 393 static int process_buildids(void)
 394 {
 395         u64 size = lseek(output, 0, SEEK_CUR);
 396
 397         session->fd = output;
 398         return __perf_session__process_events(session, post_processing_offset,
 399                                               size - post_processing_offset,
 400                                               size, &build_id__mark_dso_hit_ops);
 401 }
 402
 403 static void atexit_header(void)
 404 {
 405         session->header.data_size += bytes_written;
 406
 407         process_buildids();
 408         perf_header__write(&session->header, output, true);
 409 }
 410
 411 static int __cmd_record(int argc, const char **argv)
 412 {
 413         int i, counter;
 414         struct stat st;
 415         pid_t pid = 0;
 416         int flags;
 417         int err;
 418         unsigned long waking = 0;
 419         int child_ready_pipe[2], go_pipe[2];
 420         const bool forks = target_pid == -1 && argc > 0;
 421         char buf;
 422
 423         page_size = sysconf(_SC_PAGE_SIZE);
 424         nr_cpus = sysconf(_SC_NPROCESSORS_ONLN);
 425         assert(nr_cpus <= MAX_NR_CPUS);
 426         assert(nr_cpus >= 0);
 427
 428         atexit(sig_atexit);
 429         signal(SIGCHLD, sig_handler);
 430         signal(SIGINT, sig_handler);
 431
 432         if (forks && (pipe(child_ready_pipe) < 0 || pipe(go_pipe) < 0)) {
 433                 perror("failed to create pipes");
 434                 exit(-1);
 435         }
 436
 437         if (!stat(output_name, &st) && st.st_size) {
 438                 if (!force) {
 439                         if (!append_file) {
 440                                 pr_err("Error, output file %s exists, use -A "
 441                                        "to append or -f to overwrite.\n",
 442                                        output_name);
 443                                 exit(-1);
 444                         }
 445                 } else {
 446                         char oldname[PATH_MAX];
 447                         snprintf(oldname, sizeof(oldname), "%s.old",
 448                                  output_name);
 449                         unlink(oldname);
 450                         rename(output_name, oldname);
 451                 }
 452         } else {
 453                 append_file = 0;
 454         }
 455
 456         flags = O_CREAT|O_RDWR;
 457         if (append_file)
 458                 file_new = 0;
 459         else
 460                 flags |= O_TRUNC;
 461
 462         output = open(output_name, flags, S_IRUSR|S_IWUSR);
 463         if (output < 0) {
 464                 perror("failed to create output file");
 465                 exit(-1);
 466         }
 467
 468         session = perf_session__new(output_name, O_WRONLY, force);
 469         if (session == NULL) {
 470                 pr_err("Not enough memory for reading perf file header\n");
 471                 return -1;
 472         }
 473
 474         if (!file_new) {
 475                 err = perf_header__read(&session->header, output);
 476                 if (err < 0)
 477                         return err;
 478         }
 479
 480         if (raw_samples) {
 481                 perf_header__set_feat(&session->header, HEADER_TRACE_INFO);
 482         } else {
 483                 for (i = 0; i < nr_counters; i++) {
 484                         if (attrs[i].sample_type & PERF_SAMPLE_RAW) {
 485                                 perf_header__set_feat(&session->header, HEADER_TRACE_INFO);
 486                                 break;
 487                         }
 488                 }
 489         }
 490
 491         atexit(atexit_header);
 492
 493         if (forks) {
 494                 pid = fork();
 495                 if (pid < 0) {
 496                         perror("failed to fork");
 497                         exit(-1);
 498                 }
 499
 500                 if (!pid) {
 501                         close(child_ready_pipe[0]);
 502                         close(go_pipe[1]);
 503                         fcntl(go_pipe[0], F_SETFD, FD_CLOEXEC);
 504
 505                         /*
 506                          * Do a dummy execvp to get the PLT entry resolved,
 507                          * so we avoid the resolver overhead on the real
 508                          * execvp call.
 509                          */
 510                         execvp("", (char **)argv);
 511
 512                         /*
 513                          * Tell the parent we're ready to go
 514                          */
 515                         close(child_ready_pipe[1]);
 516
 517                         /*
 518                          * Wait until the parent tells us to go.
 519                          */
 520                         if (read(go_pipe[0], &buf, 1) == -1)
 521                                 perror("unable to read pipe");
 522
 523                         execvp(argv[0], (char **)argv);
 524
 525                         perror(argv[0]);
 526                         exit(-1);
 527                 }
 528
 529                 child_pid = pid;
 530
 531                 if (!system_wide)
 532                         target_pid = pid;
 533
 534                 close(child_ready_pipe[1]);
 535                 close(go_pipe[0]);
 536                 /*
 537                  * wait for child to settle
 538                  */
 539                 if (read(child_ready_pipe[0], &buf, 1) == -1) {
 540                         perror("unable to read pipe");
 541                         exit(-1);
 542                 }
 543                 close(child_ready_pipe[0]);
 544         }
 545
 546
 547         if ((!system_wide && !inherit) || profile_cpu != -1) {
 548                 open_counters(profile_cpu, target_pid);
 549         } else {
 550                 for (i = 0; i < nr_cpus; i++)
 551                         open_counters(i, target_pid);
 552         }
 553
 554         if (file_new) {
 555                 err = perf_header__write(&session->header, output, false);
 556                 if (err < 0)
 557                         return err;
 558         }
 559
 560         post_processing_offset = lseek(output, 0, SEEK_CUR);
 561
 562         err = event__synthesize_kernel_mmap(process_synthesized_event,
 563                                             session, "_text");
 564         if (err < 0) {
 565                 pr_err("Couldn't record kernel reference relocation symbol.\n");
 566                 return err;
 567         }
 568
 569         err = event__synthesize_modules(process_synthesized_event, session);
 570         if (err < 0) {
 571                 pr_err("Couldn't record kernel reference relocation symbol.\n");
 572                 return err;
 573         }
 574
 575         if (!system_wide && profile_cpu == -1)
 576                 event__synthesize_thread(target_pid, process_synthesized_event,
 577                                          session);
 578         else
 579                 event__synthesize_threads(process_synthesized_event, session);
 580
 581         if (realtime_prio) {
 582                 struct sched_param param;
 583
 584                 param.sched_priority = realtime_prio;
 585                 if (sched_setscheduler(0, SCHED_FIFO, &param)) {
 586                         pr_err("Could not set realtime priority.\n");
 587                         exit(-1);
 588                 }
 589         }
 590
 591         /*
 592          * Let the child rip
 593          */
 594         if (forks)
 595                 close(go_pipe[1]);
 596
 597         for (;;) {
 598                 int hits = samples;
 599
 600                 for (i = 0; i < nr_cpu; i++) {
 601                         for (counter = 0; counter < nr_counters; counter++) {
 602                                 if (mmap_array[i][counter].base)
 603                                         mmap_read(&mmap_array[i][counter]);
 604                         }
 605                 }
 606
 607                 if (hits == samples) {
 608                         if (done)
 609                                 break;
 610                         err = poll(event_array, nr_poll, -1);
 611                         waking++;
 612                 }
 613
 614                 if (done) {
 615                         for (i = 0; i < nr_cpu; i++) {
 616                                 for (counter = 0; counter < nr_counters; counter++)
 617                                         ioctl(fd[i][counter], PERF_EVENT_IOC_DISABLE);
 618                         }
 619                 }
 620         }
 621
 622         fprintf(stderr, "[ perf record: Woken up %ld times to write data ]\n", waking);
 623
 624         /*
 625          * Approximate RIP event size: 24 bytes.
 626          */
 627         fprintf(stderr,
 628                 "[ perf record: Captured and wrote %.3f MB %s (~%lld samples) ]\n",
 629                 (double)bytes_written / 1024.0 / 1024.0,
 630                 output_name,
 631                 bytes_written / 24);
 632
 633         return 0;
 634 }
 635
 636 static const char * const record_usage[] = {
 637         "perf record [<options>] [<command>]",
 638         "perf record [<options>] -- <command> [<options>]",
 639         NULL
 640 };
 641
 642 static const struct option options[] = {
 643         OPT_CALLBACK('e', "event", NULL, "event",
 644                      "event selector. use 'perf list' to list available events",
 645                      parse_events),
 646         OPT_CALLBACK(0, "filter", NULL, "filter",
 647                      "event filter", parse_filter),
 648         OPT_INTEGER('p', "pid", &target_pid,
 649                     "record events on existing pid"),
 650         OPT_INTEGER('r', "realtime", &realtime_prio,
 651                     "collect data with this RT SCHED_FIFO priority"),
 652         OPT_BOOLEAN('R', "raw-samples", &raw_samples,
 653                     "collect raw sample records from all opened counters"),
 654         OPT_BOOLEAN('a', "all-cpus", &system_wide,
 655                             "system-wide collection from all CPUs"),
 656         OPT_BOOLEAN('A', "append", &append_file,
 657                             "append to the output file to do incremental profiling"),
 658         OPT_INTEGER('C', "profile_cpu", &profile_cpu,
 659                             "CPU to profile on"),
 660         OPT_BOOLEAN('f', "force", &force,
 661                         "overwrite existing data file"),
 662         OPT_LONG('c', "count", &default_interval,
 663                     "event period to sample"),
 664         OPT_STRING('o', "output", &output_name, "file",
 665                     "output file name"),
 666         OPT_BOOLEAN('i', "inherit", &inherit,
 667                     "child tasks inherit counters"),
 668         OPT_INTEGER('F', "freq", &freq,
 669                     "profile at this frequency"),
 670         OPT_INTEGER('m', "mmap-pages", &mmap_pages,
 671                     "number of mmap data pages"),
 672         OPT_BOOLEAN('g', "call-graph", &call_graph,
 673                     "do call-graph (stack chain/backtrace) recording"),
 674         OPT_BOOLEAN('v', "verbose", &verbose,
 675                     "be more verbose (show counter open errors, etc)"),
 676         OPT_BOOLEAN('s', "stat", &inherit_stat,
 677                     "per thread counts"),
 678         OPT_BOOLEAN('d', "data", &sample_address,
 679                     "Sample addresses"),
 680         OPT_BOOLEAN('n', "no-samples", &no_samples,
 681                     "don't sample"),
 682         OPT_BOOLEAN('M', "multiplex", &multiplex,
 683                     "multiplex counter output in a single channel"),
 684         OPT_END()
 685 };
 686
 687 int cmd_record(int argc, const char **argv, const char *prefix __used)
 688 {
 689         int counter;
 690
 691         argc = parse_options(argc, argv, options, record_usage,
 692                             PARSE_OPT_STOP_AT_NON_OPTION);
 693         if (!argc && target_pid == -1 && !system_wide && profile_cpu == -1)
 694                 usage_with_options(record_usage, options);
 695
 696         symbol__init();
 697
 698         if (!nr_counters) {
 699                 nr_counters     = 1;
 700                 attrs[0].type   = PERF_TYPE_HARDWARE;
 701                 attrs[0].config = PERF_COUNT_HW_CPU_CYCLES;
 702         }
 703
 704         /*
 705          * User specified count overrides default frequency.
 706          */
 707         if (default_interval)
 708                 freq = 0;
 709         else if (freq) {
 710                 default_interval = freq;
 711         } else {
 712                 fprintf(stderr, "frequency and count are zero, aborting\n");
 713                 exit(EXIT_FAILURE);
 714         }
 715
 716         for (counter = 0; counter < nr_counters; counter++) {
 717                 if (attrs[counter].sample_period)
 718                         continue;
 719
 720                 attrs[counter].sample_period = default_interval;
 721         }
 722
 723         return __cmd_record(argc, argv);
 724 }