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
  19 #include <unistd.h>
  20 #include <sched.h>
  21
  22 #define ALIGN(x, a)             __ALIGN_MASK(x, (typeof(x))(a)-1)
  23 #define __ALIGN_MASK(x, mask)   (((x)+(mask))&~(mask))
  24
  25 static int                      fd[MAX_NR_CPUS][MAX_COUNTERS];
  26
  27 static long                     default_interval                = 100000;
  28
  29 static int                      nr_cpus                         = 0;
  30 static unsigned int             page_size;
  31 static unsigned int             mmap_pages                      = 128;
  32 static int                      freq                            = 0;
  33 static int                      output;
  34 static const char               *output_name                    = "perf.data";
  35 static int                      group                           = 0;
  36 static unsigned int             realtime_prio                   = 0;
  37 static int                      system_wide                     = 0;
  38 static pid_t                    target_pid                      = -1;
  39 static int                      inherit                         = 1;
  40 static int                      force                           = 0;
  41 static int                      append_file                     = 0;
  42 static int                      call_graph                      = 0;
  43 static int                      verbose                         = 0;
  44 static int                      inherit_stat                    = 0;
  45 static int                      no_samples                      = 0;
  46 static int                      sample_address                  = 0;
  47
  48 static long                     samples;
  49 static struct timeval           last_read;
  50 static struct timeval           this_read;
  51
  52 static u64                      bytes_written;
  53
  54 static struct pollfd            event_array[MAX_NR_CPUS * MAX_COUNTERS];
  55
  56 static int                      nr_poll;
  57 static int                      nr_cpu;
  58
  59 static int                      file_new = 1;
  60
  61 struct perf_header              *header;
  62
  63 struct mmap_event {
  64         struct perf_event_header        header;
  65         u32                             pid;
  66         u32                             tid;
  67         u64                             start;
  68         u64                             len;
  69         u64                             pgoff;
  70         char                            filename[PATH_MAX];
  71 };
  72
  73 struct comm_event {
  74         struct perf_event_header        header;
  75         u32                             pid;
  76         u32                             tid;
  77         char                            comm[16];
  78 };
  79
  80
  81 struct mmap_data {
  82         int                     counter;
  83         void                    *base;
  84         unsigned int            mask;
  85         unsigned int            prev;
  86 };
  87
  88 static struct mmap_data         mmap_array[MAX_NR_CPUS][MAX_COUNTERS];
  89
  90 static unsigned long mmap_read_head(struct mmap_data *md)
  91 {
  92         struct perf_counter_mmap_page *pc = md->base;
  93         long head;
  94
  95         head = pc->data_head;
  96         rmb();
  97
  98         return head;
  99 }
 100
 101 static void mmap_write_tail(struct mmap_data *md, unsigned long tail)
 102 {
 103         struct perf_counter_mmap_page *pc = md->base;
 104
 105         /*
 106          * ensure all reads are done before we write the tail out.
 107          */
 108         /* mb(); */
 109         pc->data_tail = tail;
 110 }
 111
 112 static void write_output(void *buf, size_t size)
 113 {
 114         while (size) {
 115                 int ret = write(output, buf, size);
 116
 117                 if (ret < 0)
 118                         die("failed to write");
 119
 120                 size -= ret;
 121                 buf += ret;
 122
 123                 bytes_written += ret;
 124         }
 125 }
 126
 127 static void mmap_read(struct mmap_data *md)
 128 {
 129         unsigned int head = mmap_read_head(md);
 130         unsigned int old = md->prev;
 131         unsigned char *data = md->base + page_size;
 132         unsigned long size;
 133         void *buf;
 134         int diff;
 135
 136         gettimeofday(&this_read, NULL);
 137
 138         /*
 139          * If we're further behind than half the buffer, there's a chance
 140          * the writer will bite our tail and mess up the samples under us.
 141          *
 142          * If we somehow ended up ahead of the head, we got messed up.
 143          *
 144          * In either case, truncate and restart at head.
 145          */
 146         diff = head - old;
 147         if (diff < 0) {
 148                 struct timeval iv;
 149                 unsigned long msecs;
 150
 151                 timersub(&this_read, &last_read, &iv);
 152                 msecs = iv.tv_sec*1000 + iv.tv_usec/1000;
 153
 154                 fprintf(stderr, "WARNING: failed to keep up with mmap data."
 155                                 "  Last read %lu msecs ago.\n", msecs);
 156
 157                 /*
 158                  * head points to a known good entry, start there.
 159                  */
 160                 old = head;
 161         }
 162
 163         last_read = this_read;
 164
 165         if (old != head)
 166                 samples++;
 167
 168         size = head - old;
 169
 170         if ((old & md->mask) + size != (head & md->mask)) {
 171                 buf = &data[old & md->mask];
 172                 size = md->mask + 1 - (old & md->mask);
 173                 old += size;
 174
 175                 write_output(buf, size);
 176         }
 177
 178         buf = &data[old & md->mask];
 179         size = head - old;
 180         old += size;
 181
 182         write_output(buf, size);
 183
 184         md->prev = old;
 185         mmap_write_tail(md, old);
 186 }
 187
 188 static volatile int done = 0;
 189 static volatile int signr = -1;
 190
 191 static void sig_handler(int sig)
 192 {
 193         done = 1;
 194         signr = sig;
 195 }
 196
 197 static void sig_atexit(void)
 198 {
 199         if (signr == -1)
 200                 return;
 201
 202         signal(signr, SIG_DFL);
 203         kill(getpid(), signr);
 204 }
 205
 206 static void pid_synthesize_comm_event(pid_t pid, int full)
 207 {
 208         struct comm_event comm_ev;
 209         char filename[PATH_MAX];
 210         char bf[BUFSIZ];
 211         int fd;
 212         size_t size;
 213         char *field, *sep;
 214         DIR *tasks;
 215         struct dirent dirent, *next;
 216
 217         snprintf(filename, sizeof(filename), "/proc/%d/stat", pid);
 218
 219         fd = open(filename, O_RDONLY);
 220         if (fd < 0) {
 221                 /*
 222                  * We raced with a task exiting - just return:
 223                  */
 224                 if (verbose)
 225                         fprintf(stderr, "couldn't open %s\n", filename);
 226                 return;
 227         }
 228         if (read(fd, bf, sizeof(bf)) < 0) {
 229                 fprintf(stderr, "couldn't read %s\n", filename);
 230                 exit(EXIT_FAILURE);
 231         }
 232         close(fd);
 233
 234         /* 9027 (cat) R 6747 9027 6747 34816 9027 ... */
 235         memset(&comm_ev, 0, sizeof(comm_ev));
 236         field = strchr(bf, '(');
 237         if (field == NULL)
 238                 goto out_failure;
 239         sep = strchr(++field, ')');
 240         if (sep == NULL)
 241                 goto out_failure;
 242         size = sep - field;
 243         memcpy(comm_ev.comm, field, size++);
 244
 245         comm_ev.pid = pid;
 246         comm_ev.header.type = PERF_EVENT_COMM;
 247         size = ALIGN(size, sizeof(u64));
 248         comm_ev.header.size = sizeof(comm_ev) - (sizeof(comm_ev.comm) - size);
 249
 250         if (!full) {
 251                 comm_ev.tid = pid;
 252
 253                 write_output(&comm_ev, comm_ev.header.size);
 254                 return;
 255         }
 256
 257         snprintf(filename, sizeof(filename), "/proc/%d/task", pid);
 258
 259         tasks = opendir(filename);
 260         while (!readdir_r(tasks, &dirent, &next) && next) {
 261                 char *end;
 262                 pid = strtol(dirent.d_name, &end, 10);
 263                 if (*end)
 264                         continue;
 265
 266                 comm_ev.tid = pid;
 267
 268                 write_output(&comm_ev, comm_ev.header.size);
 269         }
 270         closedir(tasks);
 271         return;
 272
 273 out_failure:
 274         fprintf(stderr, "couldn't get COMM and pgid, malformed %s\n",
 275                 filename);
 276         exit(EXIT_FAILURE);
 277 }
 278
 279 static void pid_synthesize_mmap_samples(pid_t pid)
 280 {
 281         char filename[PATH_MAX];
 282         FILE *fp;
 283
 284         snprintf(filename, sizeof(filename), "/proc/%d/maps", pid);
 285
 286         fp = fopen(filename, "r");
 287         if (fp == NULL) {
 288                 /*
 289                  * We raced with a task exiting - just return:
 290                  */
 291                 if (verbose)
 292                         fprintf(stderr, "couldn't open %s\n", filename);
 293                 return;
 294         }
 295         while (1) {
 296                 char bf[BUFSIZ], *pbf = bf;
 297                 struct mmap_event mmap_ev = {
 298                         .header = { .type = PERF_EVENT_MMAP },
 299                 };
 300                 int n;
 301                 size_t size;
 302                 if (fgets(bf, sizeof(bf), fp) == NULL)
 303                         break;
 304
 305                 /* 00400000-0040c000 r-xp 00000000 fd:01 41038  /bin/cat */
 306                 n = hex2u64(pbf, &mmap_ev.start);
 307                 if (n < 0)
 308                         continue;
 309                 pbf += n + 1;
 310                 n = hex2u64(pbf, &mmap_ev.len);
 311                 if (n < 0)
 312                         continue;
 313                 pbf += n + 3;
 314                 if (*pbf == 'x') { /* vm_exec */
 315                         char *execname = strchr(bf, '/');
 316
 317                         /* Catch VDSO */
 318                         if (execname == NULL)
 319                                 execname = strstr(bf, "[vdso]");
 320
 321                         if (execname == NULL)
 322                                 continue;
 323
 324                         size = strlen(execname);
 325                         execname[size - 1] = '\0'; /* Remove \n */
 326                         memcpy(mmap_ev.filename, execname, size);
 327                         size = ALIGN(size, sizeof(u64));
 328                         mmap_ev.len -= mmap_ev.start;
 329                         mmap_ev.header.size = (sizeof(mmap_ev) -
 330                                                (sizeof(mmap_ev.filename) - size));
 331                         mmap_ev.pid = pid;
 332                         mmap_ev.tid = pid;
 333
 334                         write_output(&mmap_ev, mmap_ev.header.size);
 335                 }
 336         }
 337
 338         fclose(fp);
 339 }
 340
 341 static void synthesize_all(void)
 342 {
 343         DIR *proc;
 344         struct dirent dirent, *next;
 345
 346         proc = opendir("/proc");
 347
 348         while (!readdir_r(proc, &dirent, &next) && next) {
 349                 char *end;
 350                 pid_t pid;
 351
 352                 pid = strtol(dirent.d_name, &end, 10);
 353                 if (*end) /* only interested in proper numerical dirents */
 354                         continue;
 355
 356                 pid_synthesize_comm_event(pid, 1);
 357                 pid_synthesize_mmap_samples(pid);
 358         }
 359
 360         closedir(proc);
 361 }
 362
 363 static int group_fd;
 364
 365 static struct perf_header_attr *get_header_attr(struct perf_counter_attr *a, int nr)
 366 {
 367         struct perf_header_attr *h_attr;
 368
 369         if (nr < header->attrs) {
 370                 h_attr = header->attr[nr];
 371         } else {
 372                 h_attr = perf_header_attr__new(a);
 373                 perf_header__add_attr(header, h_attr);
 374         }
 375
 376         return h_attr;
 377 }
 378
 379 static void create_counter(int counter, int cpu, pid_t pid)
 380 {
 381         struct perf_counter_attr *attr = attrs + counter;
 382         struct perf_header_attr *h_attr;
 383         int track = !counter; /* only the first counter needs these */
 384         struct {
 385                 u64 count;
 386                 u64 time_enabled;
 387                 u64 time_running;
 388                 u64 id;
 389         } read_data;
 390
 391         attr->read_format       = PERF_FORMAT_TOTAL_TIME_ENABLED |
 392                                   PERF_FORMAT_TOTAL_TIME_RUNNING |
 393                                   PERF_FORMAT_ID;
 394
 395         attr->sample_type       = PERF_SAMPLE_IP | PERF_SAMPLE_TID;
 396
 397         if (freq) {
 398                 attr->sample_type       |= PERF_SAMPLE_PERIOD;
 399                 attr->freq              = 1;
 400                 attr->sample_freq       = freq;
 401         }
 402
 403         if (no_samples)
 404                 attr->sample_freq = 0;
 405
 406         if (inherit_stat)
 407                 attr->inherit_stat = 1;
 408
 409         if (sample_address)
 410                 attr->sample_type       |= PERF_SAMPLE_ADDR;
 411
 412         if (call_graph)
 413                 attr->sample_type       |= PERF_SAMPLE_CALLCHAIN;
 414
 415         attr->mmap              = track;
 416         attr->comm              = track;
 417         attr->inherit           = (cpu < 0) && inherit;
 418         attr->disabled          = 1;
 419
 420 try_again:
 421         fd[nr_cpu][counter] = sys_perf_counter_open(attr, pid, cpu, group_fd, 0);
 422
 423         if (fd[nr_cpu][counter] < 0) {
 424                 int err = errno;
 425
 426                 if (err == EPERM)
 427                         die("Permission error - are you root?\n");
 428
 429                 /*
 430                  * If it's cycles then fall back to hrtimer
 431                  * based cpu-clock-tick sw counter, which
 432                  * is always available even if no PMU support:
 433                  */
 434                 if (attr->type == PERF_TYPE_HARDWARE
 435                         && attr->config == PERF_COUNT_HW_CPU_CYCLES) {
 436
 437                         if (verbose)
 438                                 warning(" ... trying to fall back to cpu-clock-ticks\n");
 439                         attr->type = PERF_TYPE_SOFTWARE;
 440                         attr->config = PERF_COUNT_SW_CPU_CLOCK;
 441                         goto try_again;
 442                 }
 443                 printf("\n");
 444                 error("perfcounter syscall returned with %d (%s)\n",
 445                         fd[nr_cpu][counter], strerror(err));
 446                 die("No CONFIG_PERF_COUNTERS=y kernel support configured?\n");
 447                 exit(-1);
 448         }
 449
 450         h_attr = get_header_attr(attr, counter);
 451
 452         if (!file_new) {
 453                 if (memcmp(&h_attr->attr, attr, sizeof(*attr))) {
 454                         fprintf(stderr, "incompatible append\n");
 455                         exit(-1);
 456                 }
 457         }
 458
 459         if (read(fd[nr_cpu][counter], &read_data, sizeof(read_data)) == -1) {
 460                 perror("Unable to read perf file descriptor\n");
 461                 exit(-1);
 462         }
 463
 464         perf_header_attr__add_id(h_attr, read_data.id);
 465
 466         assert(fd[nr_cpu][counter] >= 0);
 467         fcntl(fd[nr_cpu][counter], F_SETFL, O_NONBLOCK);
 468
 469         /*
 470          * First counter acts as the group leader:
 471          */
 472         if (group && group_fd == -1)
 473                 group_fd = fd[nr_cpu][counter];
 474
 475         event_array[nr_poll].fd = fd[nr_cpu][counter];
 476         event_array[nr_poll].events = POLLIN;
 477         nr_poll++;
 478
 479         mmap_array[nr_cpu][counter].counter = counter;
 480         mmap_array[nr_cpu][counter].prev = 0;
 481         mmap_array[nr_cpu][counter].mask = mmap_pages*page_size - 1;
 482         mmap_array[nr_cpu][counter].base = mmap(NULL, (mmap_pages+1)*page_size,
 483                         PROT_READ|PROT_WRITE, MAP_SHARED, fd[nr_cpu][counter], 0);
 484         if (mmap_array[nr_cpu][counter].base == MAP_FAILED) {
 485                 error("failed to mmap with %d (%s)\n", errno, strerror(errno));
 486                 exit(-1);
 487         }
 488
 489         ioctl(fd[nr_cpu][counter], PERF_COUNTER_IOC_ENABLE);
 490 }
 491
 492 static void open_counters(int cpu, pid_t pid)
 493 {
 494         int counter;
 495
 496         group_fd = -1;
 497         for (counter = 0; counter < nr_counters; counter++)
 498                 create_counter(counter, cpu, pid);
 499
 500         nr_cpu++;
 501 }
 502
 503 static void atexit_header(void)
 504 {
 505         header->data_size += bytes_written;
 506
 507         perf_header__write(header, output);
 508 }
 509
 510 static int __cmd_record(int argc, const char **argv)
 511 {
 512         int i, counter;
 513         struct stat st;
 514         pid_t pid = 0;
 515         int flags;
 516         int ret;
 517
 518         page_size = sysconf(_SC_PAGE_SIZE);
 519         nr_cpus = sysconf(_SC_NPROCESSORS_ONLN);
 520         assert(nr_cpus <= MAX_NR_CPUS);
 521         assert(nr_cpus >= 0);
 522
 523         atexit(sig_atexit);
 524         signal(SIGCHLD, sig_handler);
 525         signal(SIGINT, sig_handler);
 526
 527         if (!stat(output_name, &st) && !force && !append_file) {
 528                 fprintf(stderr, "Error, output file %s exists, use -A to append or -f to overwrite.\n",
 529                                 output_name);
 530                 exit(-1);
 531         }
 532
 533         flags = O_CREAT|O_RDWR;
 534         if (append_file)
 535                 file_new = 0;
 536         else
 537                 flags |= O_TRUNC;
 538
 539         output = open(output_name, flags, S_IRUSR|S_IWUSR);
 540         if (output < 0) {
 541                 perror("failed to create output file");
 542                 exit(-1);
 543         }
 544
 545         if (!file_new)
 546                 header = perf_header__read(output);
 547         else
 548                 header = perf_header__new();
 549
 550         atexit(atexit_header);
 551
 552         if (!system_wide) {
 553                 pid = target_pid;
 554                 if (pid == -1)
 555                         pid = getpid();
 556
 557                 open_counters(-1, pid);
 558         } else for (i = 0; i < nr_cpus; i++)
 559                 open_counters(i, target_pid);
 560
 561         if (file_new)
 562                 perf_header__write(header, output);
 563
 564         if (!system_wide) {
 565                 pid_synthesize_comm_event(pid, 0);
 566                 pid_synthesize_mmap_samples(pid);
 567         } else
 568                 synthesize_all();
 569
 570         if (target_pid == -1 && argc) {
 571                 pid = fork();
 572                 if (pid < 0)
 573                         perror("failed to fork");
 574
 575                 if (!pid) {
 576                         if (execvp(argv[0], (char **)argv)) {
 577                                 perror(argv[0]);
 578                                 exit(-1);
 579                         }
 580                 }
 581         }
 582
 583         if (realtime_prio) {
 584                 struct sched_param param;
 585
 586                 param.sched_priority = realtime_prio;
 587                 if (sched_setscheduler(0, SCHED_FIFO, &param)) {
 588                         printf("Could not set realtime priority.\n");
 589                         exit(-1);
 590                 }
 591         }
 592
 593         for (;;) {
 594                 int hits = samples;
 595
 596                 for (i = 0; i < nr_cpu; i++) {
 597                         for (counter = 0; counter < nr_counters; counter++)
 598                                 mmap_read(&mmap_array[i][counter]);
 599                 }
 600
 601                 if (hits == samples) {
 602                         if (done)
 603                                 break;
 604                         ret = poll(event_array, nr_poll, 100);
 605                 }
 606         }
 607
 608         /*
 609          * Approximate RIP event size: 24 bytes.
 610          */
 611         fprintf(stderr,
 612                 "[ perf record: Captured and wrote %.3f MB %s (~%lld samples) ]\n",
 613                 (double)bytes_written / 1024.0 / 1024.0,
 614                 output_name,
 615                 bytes_written / 24);
 616
 617         return 0;
 618 }
 619
 620 static const char * const record_usage[] = {
 621         "perf record [<options>] [<command>]",
 622         "perf record [<options>] -- <command> [<options>]",
 623         NULL
 624 };
 625
 626 static const struct option options[] = {
 627         OPT_CALLBACK('e', "event", NULL, "event",
 628                      "event selector. use 'perf list' to list available events",
 629                      parse_events),
 630         OPT_INTEGER('p', "pid", &target_pid,
 631                     "record events on existing pid"),
 632         OPT_INTEGER('r', "realtime", &realtime_prio,
 633                     "collect data with this RT SCHED_FIFO priority"),
 634         OPT_BOOLEAN('a', "all-cpus", &system_wide,
 635                             "system-wide collection from all CPUs"),
 636         OPT_BOOLEAN('A', "append", &append_file,
 637                             "append to the output file to do incremental profiling"),
 638         OPT_BOOLEAN('f', "force", &force,
 639                         "overwrite existing data file"),
 640         OPT_LONG('c', "count", &default_interval,
 641                     "event period to sample"),
 642         OPT_STRING('o', "output", &output_name, "file",
 643                     "output file name"),
 644         OPT_BOOLEAN('i', "inherit", &inherit,
 645                     "child tasks inherit counters"),
 646         OPT_INTEGER('F', "freq", &freq,
 647                     "profile at this frequency"),
 648         OPT_INTEGER('m', "mmap-pages", &mmap_pages,
 649                     "number of mmap data pages"),
 650         OPT_BOOLEAN('g', "call-graph", &call_graph,
 651                     "do call-graph (stack chain/backtrace) recording"),
 652         OPT_BOOLEAN('v', "verbose", &verbose,
 653                     "be more verbose (show counter open errors, etc)"),
 654         OPT_BOOLEAN('s', "stat", &inherit_stat,
 655                     "per thread counts"),
 656         OPT_BOOLEAN('d', "data", &sample_address,
 657                     "Sample addresses"),
 658         OPT_BOOLEAN('n', "no-samples", &no_samples,
 659                     "don't sample"),
 660         OPT_END()
 661 };
 662
 663 int cmd_record(int argc, const char **argv, const char *prefix __used)
 664 {
 665         int counter;
 666
 667         argc = parse_options(argc, argv, options, record_usage,
 668                 PARSE_OPT_STOP_AT_NON_OPTION);
 669         if (!argc && target_pid == -1 && !system_wide)
 670                 usage_with_options(record_usage, options);
 671
 672         if (!nr_counters) {
 673                 nr_counters     = 1;
 674                 attrs[0].type   = PERF_TYPE_HARDWARE;
 675                 attrs[0].config = PERF_COUNT_HW_CPU_CYCLES;
 676         }
 677
 678         for (counter = 0; counter < nr_counters; counter++) {
 679                 if (attrs[counter].sample_period)
 680                         continue;
 681
 682                 attrs[counter].sample_period = default_interval;
 683         }
 684
 685         return __cmd_record(argc, argv);
 686 }