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/trace-event.h"
  21
  22 #include <unistd.h>
  23 #include <sched.h>
  24
  25 #define ALIGN(x, a)             __ALIGN_MASK(x, (typeof(x))(a)-1)
  26 #define __ALIGN_MASK(x, mask)   (((x)+(mask))&~(mask))
  27
  28 static int                      fd[MAX_NR_CPUS][MAX_COUNTERS];
  29
  30 static long                     default_interval                = 100000;
  31
  32 static int                      nr_cpus                         = 0;
  33 static unsigned int             page_size;
  34 static unsigned int             mmap_pages                      = 128;
  35 static int                      freq                            = 0;
  36 static int                      output;
  37 static const char               *output_name                    = "perf.data";
  38 static int                      group                           = 0;
  39 static unsigned int             realtime_prio                   = 0;
  40 static int                      raw_samples                     = 0;
  41 static int                      system_wide                     = 0;
  42 static int                      profile_cpu                     = -1;
  43 static pid_t                    target_pid                      = -1;
  44 static int                      inherit                         = 1;
  45 static int                      force                           = 0;
  46 static int                      append_file                     = 0;
  47 static int                      call_graph                      = 0;
  48 static int                      inherit_stat                    = 0;
  49 static int                      no_samples                      = 0;
  50 static int                      sample_address                  = 0;
  51
  52 static long                     samples;
  53 static struct timeval           last_read;
  54 static struct timeval           this_read;
  55
  56 static u64                      bytes_written;
  57
  58 static struct pollfd            event_array[MAX_NR_CPUS * MAX_COUNTERS];
  59
  60 static int                      nr_poll;
  61 static int                      nr_cpu;
  62
  63 static int                      file_new = 1;
  64
  65 struct perf_header              *header;
  66
  67 struct mmap_data {
  68         int                     counter;
  69         void                    *base;
  70         unsigned int            mask;
  71         unsigned int            prev;
  72 };
  73
  74 static struct mmap_data         mmap_array[MAX_NR_CPUS][MAX_COUNTERS];
  75
  76 static unsigned long mmap_read_head(struct mmap_data *md)
  77 {
  78         struct perf_counter_mmap_page *pc = md->base;
  79         long head;
  80
  81         head = pc->data_head;
  82         rmb();
  83
  84         return head;
  85 }
  86
  87 static void mmap_write_tail(struct mmap_data *md, unsigned long tail)
  88 {
  89         struct perf_counter_mmap_page *pc = md->base;
  90
  91         /*
  92          * ensure all reads are done before we write the tail out.
  93          */
  94         /* mb(); */
  95         pc->data_tail = tail;
  96 }
  97
  98 static void write_output(void *buf, size_t size)
  99 {
 100         while (size) {
 101                 int ret = write(output, buf, size);
 102
 103                 if (ret < 0)
 104                         die("failed to write");
 105
 106                 size -= ret;
 107                 buf += ret;
 108
 109                 bytes_written += ret;
 110         }
 111 }
 112
 113 static void mmap_read(struct mmap_data *md)
 114 {
 115         unsigned int head = mmap_read_head(md);
 116         unsigned int old = md->prev;
 117         unsigned char *data = md->base + page_size;
 118         unsigned long size;
 119         void *buf;
 120         int diff;
 121
 122         gettimeofday(&this_read, NULL);
 123
 124         /*
 125          * If we're further behind than half the buffer, there's a chance
 126          * the writer will bite our tail and mess up the samples under us.
 127          *
 128          * If we somehow ended up ahead of the head, we got messed up.
 129          *
 130          * In either case, truncate and restart at head.
 131          */
 132         diff = head - old;
 133         if (diff < 0) {
 134                 struct timeval iv;
 135                 unsigned long msecs;
 136
 137                 timersub(&this_read, &last_read, &iv);
 138                 msecs = iv.tv_sec*1000 + iv.tv_usec/1000;
 139
 140                 fprintf(stderr, "WARNING: failed to keep up with mmap data."
 141                                 "  Last read %lu msecs ago.\n", msecs);
 142
 143                 /*
 144                  * head points to a known good entry, start there.
 145                  */
 146                 old = head;
 147         }
 148
 149         last_read = this_read;
 150
 151         if (old != head)
 152                 samples++;
 153
 154         size = head - old;
 155
 156         if ((old & md->mask) + size != (head & md->mask)) {
 157                 buf = &data[old & md->mask];
 158                 size = md->mask + 1 - (old & md->mask);
 159                 old += size;
 160
 161                 write_output(buf, size);
 162         }
 163
 164         buf = &data[old & md->mask];
 165         size = head - old;
 166         old += size;
 167
 168         write_output(buf, size);
 169
 170         md->prev = old;
 171         mmap_write_tail(md, old);
 172 }
 173
 174 static volatile int done = 0;
 175 static volatile int signr = -1;
 176
 177 static void sig_handler(int sig)
 178 {
 179         done = 1;
 180         signr = sig;
 181 }
 182
 183 static void sig_atexit(void)
 184 {
 185         if (signr == -1)
 186                 return;
 187
 188         signal(signr, SIG_DFL);
 189         kill(getpid(), signr);
 190 }
 191
 192 static pid_t pid_synthesize_comm_event(pid_t pid, int full)
 193 {
 194         struct comm_event comm_ev;
 195         char filename[PATH_MAX];
 196         char bf[BUFSIZ];
 197         FILE *fp;
 198         size_t size = 0;
 199         DIR *tasks;
 200         struct dirent dirent, *next;
 201         pid_t tgid = 0;
 202
 203         snprintf(filename, sizeof(filename), "/proc/%d/status", pid);
 204
 205         fp = fopen(filename, "r");
 206         if (fp == NULL) {
 207                 /*
 208                  * We raced with a task exiting - just return:
 209                  */
 210                 if (verbose)
 211                         fprintf(stderr, "couldn't open %s\n", filename);
 212                 return 0;
 213         }
 214
 215         memset(&comm_ev, 0, sizeof(comm_ev));
 216         while (!comm_ev.comm[0] || !comm_ev.pid) {
 217                 if (fgets(bf, sizeof(bf), fp) == NULL)
 218                         goto out_failure;
 219
 220                 if (memcmp(bf, "Name:", 5) == 0) {
 221                         char *name = bf + 5;
 222                         while (*name && isspace(*name))
 223                                 ++name;
 224                         size = strlen(name) - 1;
 225                         memcpy(comm_ev.comm, name, size++);
 226                 } else if (memcmp(bf, "Tgid:", 5) == 0) {
 227                         char *tgids = bf + 5;
 228                         while (*tgids && isspace(*tgids))
 229                                 ++tgids;
 230                         tgid = comm_ev.pid = atoi(tgids);
 231                 }
 232         }
 233
 234         comm_ev.header.type = PERF_EVENT_COMM;
 235         size = ALIGN(size, sizeof(u64));
 236         comm_ev.header.size = sizeof(comm_ev) - (sizeof(comm_ev.comm) - size);
 237
 238         if (!full) {
 239                 comm_ev.tid = pid;
 240
 241                 write_output(&comm_ev, comm_ev.header.size);
 242                 goto out_fclose;
 243         }
 244
 245         snprintf(filename, sizeof(filename), "/proc/%d/task", pid);
 246
 247         tasks = opendir(filename);
 248         while (!readdir_r(tasks, &dirent, &next) && next) {
 249                 char *end;
 250                 pid = strtol(dirent.d_name, &end, 10);
 251                 if (*end)
 252                         continue;
 253
 254                 comm_ev.tid = pid;
 255
 256                 write_output(&comm_ev, comm_ev.header.size);
 257         }
 258         closedir(tasks);
 259
 260 out_fclose:
 261         fclose(fp);
 262         return tgid;
 263
 264 out_failure:
 265         fprintf(stderr, "couldn't get COMM and pgid, malformed %s\n",
 266                 filename);
 267         exit(EXIT_FAILURE);
 268 }
 269
 270 static void pid_synthesize_mmap_samples(pid_t pid, pid_t tgid)
 271 {
 272         char filename[PATH_MAX];
 273         FILE *fp;
 274
 275         snprintf(filename, sizeof(filename), "/proc/%d/maps", pid);
 276
 277         fp = fopen(filename, "r");
 278         if (fp == NULL) {
 279                 /*
 280                  * We raced with a task exiting - just return:
 281                  */
 282                 if (verbose)
 283                         fprintf(stderr, "couldn't open %s\n", filename);
 284                 return;
 285         }
 286         while (1) {
 287                 char bf[BUFSIZ], *pbf = bf;
 288                 struct mmap_event mmap_ev = {
 289                         .header = { .type = PERF_EVENT_MMAP },
 290                 };
 291                 int n;
 292                 size_t size;
 293                 if (fgets(bf, sizeof(bf), fp) == NULL)
 294                         break;
 295
 296                 /* 00400000-0040c000 r-xp 00000000 fd:01 41038  /bin/cat */
 297                 n = hex2u64(pbf, &mmap_ev.start);
 298                 if (n < 0)
 299                         continue;
 300                 pbf += n + 1;
 301                 n = hex2u64(pbf, &mmap_ev.len);
 302                 if (n < 0)
 303                         continue;
 304                 pbf += n + 3;
 305                 if (*pbf == 'x') { /* vm_exec */
 306                         char *execname = strchr(bf, '/');
 307
 308                         /* Catch VDSO */
 309                         if (execname == NULL)
 310                                 execname = strstr(bf, "[vdso]");
 311
 312                         if (execname == NULL)
 313                                 continue;
 314
 315                         size = strlen(execname);
 316                         execname[size - 1] = '\0'; /* Remove \n */
 317                         memcpy(mmap_ev.filename, execname, size);
 318                         size = ALIGN(size, sizeof(u64));
 319                         mmap_ev.len -= mmap_ev.start;
 320                         mmap_ev.header.size = (sizeof(mmap_ev) -
 321                                                (sizeof(mmap_ev.filename) - size));
 322                         mmap_ev.pid = tgid;
 323                         mmap_ev.tid = pid;
 324
 325                         write_output(&mmap_ev, mmap_ev.header.size);
 326                 }
 327         }
 328
 329         fclose(fp);
 330 }
 331
 332 static void synthesize_all(void)
 333 {
 334         DIR *proc;
 335         struct dirent dirent, *next;
 336
 337         proc = opendir("/proc");
 338
 339         while (!readdir_r(proc, &dirent, &next) && next) {
 340                 char *end;
 341                 pid_t pid, tgid;
 342
 343                 pid = strtol(dirent.d_name, &end, 10);
 344                 if (*end) /* only interested in proper numerical dirents */
 345                         continue;
 346
 347                 tgid = pid_synthesize_comm_event(pid, 1);
 348                 pid_synthesize_mmap_samples(pid, tgid);
 349         }
 350
 351         closedir(proc);
 352 }
 353
 354 static int group_fd;
 355
 356 static struct perf_header_attr *get_header_attr(struct perf_counter_attr *a, int nr)
 357 {
 358         struct perf_header_attr *h_attr;
 359
 360         if (nr < header->attrs) {
 361                 h_attr = header->attr[nr];
 362         } else {
 363                 h_attr = perf_header_attr__new(a);
 364                 perf_header__add_attr(header, h_attr);
 365         }
 366
 367         return h_attr;
 368 }
 369
 370 static void create_counter(int counter, int cpu, pid_t pid)
 371 {
 372         struct perf_counter_attr *attr = attrs + counter;
 373         struct perf_header_attr *h_attr;
 374         int track = !counter; /* only the first counter needs these */
 375         struct {
 376                 u64 count;
 377                 u64 time_enabled;
 378                 u64 time_running;
 379                 u64 id;
 380         } read_data;
 381
 382         attr->read_format       = PERF_FORMAT_TOTAL_TIME_ENABLED |
 383                                   PERF_FORMAT_TOTAL_TIME_RUNNING |
 384                                   PERF_FORMAT_ID;
 385
 386         attr->sample_type       |= PERF_SAMPLE_IP | PERF_SAMPLE_TID;
 387
 388         if (freq) {
 389                 attr->sample_type       |= PERF_SAMPLE_PERIOD;
 390                 attr->freq              = 1;
 391                 attr->sample_freq       = freq;
 392         }
 393
 394         if (no_samples)
 395                 attr->sample_freq = 0;
 396
 397         if (inherit_stat)
 398                 attr->inherit_stat = 1;
 399
 400         if (sample_address)
 401                 attr->sample_type       |= PERF_SAMPLE_ADDR;
 402
 403         if (call_graph)
 404                 attr->sample_type       |= PERF_SAMPLE_CALLCHAIN;
 405
 406         if (raw_samples) {
 407                 attr->sample_type       |= PERF_SAMPLE_RAW;
 408                 attr->sample_type       |= PERF_SAMPLE_CPU;
 409         }
 410
 411         attr->mmap              = track;
 412         attr->comm              = track;
 413         attr->inherit           = (cpu < 0) && inherit;
 414         attr->disabled          = 1;
 415
 416 try_again:
 417         fd[nr_cpu][counter] = sys_perf_counter_open(attr, pid, cpu, group_fd, 0);
 418
 419         if (fd[nr_cpu][counter] < 0) {
 420                 int err = errno;
 421
 422                 if (err == EPERM)
 423                         die("Permission error - are you root?\n");
 424                 else if (err ==  ENODEV && profile_cpu != -1)
 425                         die("No such device - did you specify an out-of-range profile CPU?\n");
 426
 427                 /*
 428                  * If it's cycles then fall back to hrtimer
 429                  * based cpu-clock-tick sw counter, which
 430                  * is always available even if no PMU support:
 431                  */
 432                 if (attr->type == PERF_TYPE_HARDWARE
 433                         && attr->config == PERF_COUNT_HW_CPU_CYCLES) {
 434
 435                         if (verbose)
 436                                 warning(" ... trying to fall back to cpu-clock-ticks\n");
 437                         attr->type = PERF_TYPE_SOFTWARE;
 438                         attr->config = PERF_COUNT_SW_CPU_CLOCK;
 439                         goto try_again;
 440                 }
 441                 printf("\n");
 442                 error("perfcounter syscall returned with %d (%s)\n",
 443                         fd[nr_cpu][counter], strerror(err));
 444                 die("No CONFIG_PERF_COUNTERS=y kernel support configured?\n");
 445                 exit(-1);
 446         }
 447
 448         h_attr = get_header_attr(attr, counter);
 449
 450         if (!file_new) {
 451                 if (memcmp(&h_attr->attr, attr, sizeof(*attr))) {
 452                         fprintf(stderr, "incompatible append\n");
 453                         exit(-1);
 454                 }
 455         }
 456
 457         if (read(fd[nr_cpu][counter], &read_data, sizeof(read_data)) == -1) {
 458                 perror("Unable to read perf file descriptor\n");
 459                 exit(-1);
 460         }
 461
 462         perf_header_attr__add_id(h_attr, read_data.id);
 463
 464         assert(fd[nr_cpu][counter] >= 0);
 465         fcntl(fd[nr_cpu][counter], F_SETFL, O_NONBLOCK);
 466
 467         /*
 468          * First counter acts as the group leader:
 469          */
 470         if (group && group_fd == -1)
 471                 group_fd = fd[nr_cpu][counter];
 472
 473         event_array[nr_poll].fd = fd[nr_cpu][counter];
 474         event_array[nr_poll].events = POLLIN;
 475         nr_poll++;
 476
 477         mmap_array[nr_cpu][counter].counter = counter;
 478         mmap_array[nr_cpu][counter].prev = 0;
 479         mmap_array[nr_cpu][counter].mask = mmap_pages*page_size - 1;
 480         mmap_array[nr_cpu][counter].base = mmap(NULL, (mmap_pages+1)*page_size,
 481                         PROT_READ|PROT_WRITE, MAP_SHARED, fd[nr_cpu][counter], 0);
 482         if (mmap_array[nr_cpu][counter].base == MAP_FAILED) {
 483                 error("failed to mmap with %d (%s)\n", errno, strerror(errno));
 484                 exit(-1);
 485         }
 486
 487         ioctl(fd[nr_cpu][counter], PERF_COUNTER_IOC_ENABLE);
 488 }
 489
 490 static void open_counters(int cpu, pid_t pid)
 491 {
 492         int counter;
 493
 494         group_fd = -1;
 495         for (counter = 0; counter < nr_counters; counter++)
 496                 create_counter(counter, cpu, pid);
 497
 498         nr_cpu++;
 499 }
 500
 501 static void atexit_header(void)
 502 {
 503         header->data_size += bytes_written;
 504
 505         perf_header__write(header, output);
 506 }
 507
 508 static int __cmd_record(int argc, const char **argv)
 509 {
 510         int i, counter;
 511         struct stat st;
 512         pid_t pid = 0;
 513         int flags;
 514         int ret;
 515
 516         page_size = sysconf(_SC_PAGE_SIZE);
 517         nr_cpus = sysconf(_SC_NPROCESSORS_ONLN);
 518         assert(nr_cpus <= MAX_NR_CPUS);
 519         assert(nr_cpus >= 0);
 520
 521         atexit(sig_atexit);
 522         signal(SIGCHLD, sig_handler);
 523         signal(SIGINT, sig_handler);
 524
 525         if (!stat(output_name, &st) && st.st_size) {
 526                 if (!force && !append_file) {
 527                         fprintf(stderr, "Error, output file %s exists, use -A to append or -f to overwrite.\n",
 528                                         output_name);
 529                         exit(-1);
 530                 }
 531         } else {
 532                 append_file = 0;
 533         }
 534
 535         flags = O_CREAT|O_RDWR;
 536         if (append_file)
 537                 file_new = 0;
 538         else
 539                 flags |= O_TRUNC;
 540
 541         output = open(output_name, flags, S_IRUSR|S_IWUSR);
 542         if (output < 0) {
 543                 perror("failed to create output file");
 544                 exit(-1);
 545         }
 546
 547         if (!file_new)
 548                 header = perf_header__read(output);
 549         else
 550                 header = perf_header__new();
 551
 552
 553         if (raw_samples) {
 554                 read_tracing_data(attrs, nr_counters);
 555         } else {
 556                 for (i = 0; i < nr_counters; i++) {
 557                         if (attrs[i].sample_type & PERF_SAMPLE_RAW) {
 558                                 read_tracing_data(attrs, nr_counters);
 559                                 break;
 560                         }
 561                 }
 562         }
 563         atexit(atexit_header);
 564
 565         if (!system_wide) {
 566                 pid = target_pid;
 567                 if (pid == -1)
 568                         pid = getpid();
 569
 570                 open_counters(profile_cpu, pid);
 571         } else {
 572                 if (profile_cpu != -1) {
 573                         open_counters(profile_cpu, target_pid);
 574                 } else {
 575                         for (i = 0; i < nr_cpus; i++)
 576                                 open_counters(i, target_pid);
 577                 }
 578         }
 579
 580         if (file_new)
 581                 perf_header__write(header, output);
 582
 583         if (!system_wide) {
 584                 pid_t tgid = pid_synthesize_comm_event(pid, 0);
 585                 pid_synthesize_mmap_samples(pid, tgid);
 586         } else
 587                 synthesize_all();
 588
 589         if (target_pid == -1 && argc) {
 590                 pid = fork();
 591                 if (pid < 0)
 592                         perror("failed to fork");
 593
 594                 if (!pid) {
 595                         if (execvp(argv[0], (char **)argv)) {
 596                                 perror(argv[0]);
 597                                 exit(-1);
 598                         }
 599                 }
 600         }
 601
 602         if (realtime_prio) {
 603                 struct sched_param param;
 604
 605                 param.sched_priority = realtime_prio;
 606                 if (sched_setscheduler(0, SCHED_FIFO, &param)) {
 607                         printf("Could not set realtime priority.\n");
 608                         exit(-1);
 609                 }
 610         }
 611
 612         for (;;) {
 613                 int hits = samples;
 614
 615                 for (i = 0; i < nr_cpu; i++) {
 616                         for (counter = 0; counter < nr_counters; counter++)
 617                                 mmap_read(&mmap_array[i][counter]);
 618                 }
 619
 620                 if (hits == samples) {
 621                         if (done)
 622                                 break;
 623                         ret = poll(event_array, nr_poll, 100);
 624                 }
 625         }
 626
 627         /*
 628          * Approximate RIP event size: 24 bytes.
 629          */
 630         fprintf(stderr,
 631                 "[ perf record: Captured and wrote %.3f MB %s (~%lld samples) ]\n",
 632                 (double)bytes_written / 1024.0 / 1024.0,
 633                 output_name,
 634                 bytes_written / 24);
 635
 636         return 0;
 637 }
 638
 639 static const char * const record_usage[] = {
 640         "perf record [<options>] [<command>]",
 641         "perf record [<options>] -- <command> [<options>]",
 642         NULL
 643 };
 644
 645 static const struct option options[] = {
 646         OPT_CALLBACK('e', "event", NULL, "event",
 647                      "event selector. use 'perf list' to list available events",
 648                      parse_events),
 649         OPT_INTEGER('p', "pid", &target_pid,
 650                     "record events on existing pid"),
 651         OPT_INTEGER('r', "realtime", &realtime_prio,
 652                     "collect data with this RT SCHED_FIFO priority"),
 653         OPT_BOOLEAN('R', "raw-samples", &raw_samples,
 654                     "collect raw sample records from all opened counters"),
 655         OPT_BOOLEAN('a', "all-cpus", &system_wide,
 656                             "system-wide collection from all CPUs"),
 657         OPT_BOOLEAN('A', "append", &append_file,
 658                             "append to the output file to do incremental profiling"),
 659         OPT_INTEGER('C', "profile_cpu", &profile_cpu,
 660                             "CPU to profile on"),
 661         OPT_BOOLEAN('f', "force", &force,
 662                         "overwrite existing data file"),
 663         OPT_LONG('c', "count", &default_interval,
 664                     "event period to sample"),
 665         OPT_STRING('o', "output", &output_name, "file",
 666                     "output file name"),
 667         OPT_BOOLEAN('i', "inherit", &inherit,
 668                     "child tasks inherit counters"),
 669         OPT_INTEGER('F', "freq", &freq,
 670                     "profile at this frequency"),
 671         OPT_INTEGER('m', "mmap-pages", &mmap_pages,
 672                     "number of mmap data pages"),
 673         OPT_BOOLEAN('g', "call-graph", &call_graph,
 674                     "do call-graph (stack chain/backtrace) recording"),
 675         OPT_BOOLEAN('v', "verbose", &verbose,
 676                     "be more verbose (show counter open errors, etc)"),
 677         OPT_BOOLEAN('s', "stat", &inherit_stat,
 678                     "per thread counts"),
 679         OPT_BOOLEAN('d', "data", &sample_address,
 680                     "Sample addresses"),
 681         OPT_BOOLEAN('n', "no-samples", &no_samples,
 682                     "don't sample"),
 683         OPT_END()
 684 };
 685
 686 int cmd_record(int argc, const char **argv, const char *prefix __used)
 687 {
 688         int counter;
 689
 690         argc = parse_options(argc, argv, options, record_usage,
 691                 PARSE_OPT_STOP_AT_NON_OPTION);
 692         if (!argc && target_pid == -1 && !system_wide)
 693                 usage_with_options(record_usage, options);
 694
 695         if (!nr_counters) {
 696                 nr_counters     = 1;
 697                 attrs[0].type   = PERF_TYPE_HARDWARE;
 698                 attrs[0].config = PERF_COUNT_HW_CPU_CYCLES;
 699         }
 700
 701         for (counter = 0; counter < nr_counters; counter++) {
 702                 if (attrs[counter].sample_period)
 703                         continue;
 704
 705                 attrs[counter].sample_period = default_interval;
 706         }
 707
 708         return __cmd_record(argc, argv);
 709 }