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                      raw_samples                     = 0;
  38 static int                      system_wide                     = 0;
  39 static int                      profile_cpu                     = -1;
  40 static pid_t                    target_pid                      = -1;
  41 static int                      inherit                         = 1;
  42 static int                      force                           = 0;
  43 static int                      append_file                     = 0;
  44 static int                      call_graph                      = 0;
  45 static int                      verbose                         = 0;
  46 static int                      inherit_stat                    = 0;
  47 static int                      no_samples                      = 0;
  48 static int                      sample_address                  = 0;
  49
  50 static long                     samples;
  51 static struct timeval           last_read;
  52 static struct timeval           this_read;
  53
  54 static u64                      bytes_written;
  55
  56 static struct pollfd            event_array[MAX_NR_CPUS * MAX_COUNTERS];
  57
  58 static int                      nr_poll;
  59 static int                      nr_cpu;
  60
  61 static int                      file_new = 1;
  62
  63 struct perf_header              *header;
  64
  65 struct mmap_event {
  66         struct perf_event_header        header;
  67         u32                             pid;
  68         u32                             tid;
  69         u64                             start;
  70         u64                             len;
  71         u64                             pgoff;
  72         char                            filename[PATH_MAX];
  73 };
  74
  75 struct comm_event {
  76         struct perf_event_header        header;
  77         u32                             pid;
  78         u32                             tid;
  79         char                            comm[16];
  80 };
  81
  82
  83 struct mmap_data {
  84         int                     counter;
  85         void                    *base;
  86         unsigned int            mask;
  87         unsigned int            prev;
  88 };
  89
  90 static struct mmap_data         mmap_array[MAX_NR_CPUS][MAX_COUNTERS];
  91
  92 static unsigned long mmap_read_head(struct mmap_data *md)
  93 {
  94         struct perf_counter_mmap_page *pc = md->base;
  95         long head;
  96
  97         head = pc->data_head;
  98         rmb();
  99
 100         return head;
 101 }
 102
 103 static void mmap_write_tail(struct mmap_data *md, unsigned long tail)
 104 {
 105         struct perf_counter_mmap_page *pc = md->base;
 106
 107         /*
 108          * ensure all reads are done before we write the tail out.
 109          */
 110         /* mb(); */
 111         pc->data_tail = tail;
 112 }
 113
 114 static void write_output(void *buf, size_t size)
 115 {
 116         while (size) {
 117                 int ret = write(output, buf, size);
 118
 119                 if (ret < 0)
 120                         die("failed to write");
 121
 122                 size -= ret;
 123                 buf += ret;
 124
 125                 bytes_written += ret;
 126         }
 127 }
 128
 129 static void mmap_read(struct mmap_data *md)
 130 {
 131         unsigned int head = mmap_read_head(md);
 132         unsigned int old = md->prev;
 133         unsigned char *data = md->base + page_size;
 134         unsigned long size;
 135         void *buf;
 136         int diff;
 137
 138         gettimeofday(&this_read, NULL);
 139
 140         /*
 141          * If we're further behind than half the buffer, there's a chance
 142          * the writer will bite our tail and mess up the samples under us.
 143          *
 144          * If we somehow ended up ahead of the head, we got messed up.
 145          *
 146          * In either case, truncate and restart at head.
 147          */
 148         diff = head - old;
 149         if (diff < 0) {
 150                 struct timeval iv;
 151                 unsigned long msecs;
 152
 153                 timersub(&this_read, &last_read, &iv);
 154                 msecs = iv.tv_sec*1000 + iv.tv_usec/1000;
 155
 156                 fprintf(stderr, "WARNING: failed to keep up with mmap data."
 157                                 "  Last read %lu msecs ago.\n", msecs);
 158
 159                 /*
 160                  * head points to a known good entry, start there.
 161                  */
 162                 old = head;
 163         }
 164
 165         last_read = this_read;
 166
 167         if (old != head)
 168                 samples++;
 169
 170         size = head - old;
 171
 172         if ((old & md->mask) + size != (head & md->mask)) {
 173                 buf = &data[old & md->mask];
 174                 size = md->mask + 1 - (old & md->mask);
 175                 old += size;
 176
 177                 write_output(buf, size);
 178         }
 179
 180         buf = &data[old & md->mask];
 181         size = head - old;
 182         old += size;
 183
 184         write_output(buf, size);
 185
 186         md->prev = old;
 187         mmap_write_tail(md, old);
 188 }
 189
 190 static volatile int done = 0;
 191 static volatile int signr = -1;
 192
 193 static void sig_handler(int sig)
 194 {
 195         done = 1;
 196         signr = sig;
 197 }
 198
 199 static void sig_atexit(void)
 200 {
 201         if (signr == -1)
 202                 return;
 203
 204         signal(signr, SIG_DFL);
 205         kill(getpid(), signr);
 206 }
 207
 208 static pid_t pid_synthesize_comm_event(pid_t pid, int full)
 209 {
 210         struct comm_event comm_ev;
 211         char filename[PATH_MAX];
 212         char bf[BUFSIZ];
 213         FILE *fp;
 214         size_t size = 0;
 215         DIR *tasks;
 216         struct dirent dirent, *next;
 217         pid_t tgid = 0;
 218
 219         snprintf(filename, sizeof(filename), "/proc/%d/status", pid);
 220
 221         fp = fopen(filename, "r");
 222         if (fp == NULL) {
 223                 /*
 224                  * We raced with a task exiting - just return:
 225                  */
 226                 if (verbose)
 227                         fprintf(stderr, "couldn't open %s\n", filename);
 228                 return 0;
 229         }
 230
 231         memset(&comm_ev, 0, sizeof(comm_ev));
 232         while (!comm_ev.comm[0] || !comm_ev.pid) {
 233                 if (fgets(bf, sizeof(bf), fp) == NULL)
 234                         goto out_failure;
 235
 236                 if (memcmp(bf, "Name:", 5) == 0) {
 237                         char *name = bf + 5;
 238                         while (*name && isspace(*name))
 239                                 ++name;
 240                         size = strlen(name) - 1;
 241                         memcpy(comm_ev.comm, name, size++);
 242                 } else if (memcmp(bf, "Tgid:", 5) == 0) {
 243                         char *tgids = bf + 5;
 244                         while (*tgids && isspace(*tgids))
 245                                 ++tgids;
 246                         tgid = comm_ev.pid = atoi(tgids);
 247                 }
 248         }
 249
 250         comm_ev.header.type = PERF_EVENT_COMM;
 251         size = ALIGN(size, sizeof(u64));
 252         comm_ev.header.size = sizeof(comm_ev) - (sizeof(comm_ev.comm) - size);
 253
 254         if (!full) {
 255                 comm_ev.tid = pid;
 256
 257                 write_output(&comm_ev, comm_ev.header.size);
 258                 goto out_fclose;
 259         }
 260
 261         snprintf(filename, sizeof(filename), "/proc/%d/task", pid);
 262
 263         tasks = opendir(filename);
 264         while (!readdir_r(tasks, &dirent, &next) && next) {
 265                 char *end;
 266                 pid = strtol(dirent.d_name, &end, 10);
 267                 if (*end)
 268                         continue;
 269
 270                 comm_ev.tid = pid;
 271
 272                 write_output(&comm_ev, comm_ev.header.size);
 273         }
 274         closedir(tasks);
 275
 276 out_fclose:
 277         fclose(fp);
 278         return tgid;
 279
 280 out_failure:
 281         fprintf(stderr, "couldn't get COMM and pgid, malformed %s\n",
 282                 filename);
 283         exit(EXIT_FAILURE);
 284 }
 285
 286 static void pid_synthesize_mmap_samples(pid_t pid, pid_t tgid)
 287 {
 288         char filename[PATH_MAX];
 289         FILE *fp;
 290
 291         snprintf(filename, sizeof(filename), "/proc/%d/maps", pid);
 292
 293         fp = fopen(filename, "r");
 294         if (fp == NULL) {
 295                 /*
 296                  * We raced with a task exiting - just return:
 297                  */
 298                 if (verbose)
 299                         fprintf(stderr, "couldn't open %s\n", filename);
 300                 return;
 301         }
 302         while (1) {
 303                 char bf[BUFSIZ], *pbf = bf;
 304                 struct mmap_event mmap_ev = {
 305                         .header = { .type = PERF_EVENT_MMAP },
 306                 };
 307                 int n;
 308                 size_t size;
 309                 if (fgets(bf, sizeof(bf), fp) == NULL)
 310                         break;
 311
 312                 /* 00400000-0040c000 r-xp 00000000 fd:01 41038  /bin/cat */
 313                 n = hex2u64(pbf, &mmap_ev.start);
 314                 if (n < 0)
 315                         continue;
 316                 pbf += n + 1;
 317                 n = hex2u64(pbf, &mmap_ev.len);
 318                 if (n < 0)
 319                         continue;
 320                 pbf += n + 3;
 321                 if (*pbf == 'x') { /* vm_exec */
 322                         char *execname = strchr(bf, '/');
 323
 324                         /* Catch VDSO */
 325                         if (execname == NULL)
 326                                 execname = strstr(bf, "[vdso]");
 327
 328                         if (execname == NULL)
 329                                 continue;
 330
 331                         size = strlen(execname);
 332                         execname[size - 1] = '\0'; /* Remove \n */
 333                         memcpy(mmap_ev.filename, execname, size);
 334                         size = ALIGN(size, sizeof(u64));
 335                         mmap_ev.len -= mmap_ev.start;
 336                         mmap_ev.header.size = (sizeof(mmap_ev) -
 337                                                (sizeof(mmap_ev.filename) - size));
 338                         mmap_ev.pid = tgid;
 339                         mmap_ev.tid = pid;
 340
 341                         write_output(&mmap_ev, mmap_ev.header.size);
 342                 }
 343         }
 344
 345         fclose(fp);
 346 }
 347
 348 static void synthesize_all(void)
 349 {
 350         DIR *proc;
 351         struct dirent dirent, *next;
 352
 353         proc = opendir("/proc");
 354
 355         while (!readdir_r(proc, &dirent, &next) && next) {
 356                 char *end;
 357                 pid_t pid, tgid;
 358
 359                 pid = strtol(dirent.d_name, &end, 10);
 360                 if (*end) /* only interested in proper numerical dirents */
 361                         continue;
 362
 363                 tgid = pid_synthesize_comm_event(pid, 1);
 364                 pid_synthesize_mmap_samples(pid, tgid);
 365         }
 366
 367         closedir(proc);
 368 }
 369
 370 static int group_fd;
 371
 372 static struct perf_header_attr *get_header_attr(struct perf_counter_attr *a, int nr)
 373 {
 374         struct perf_header_attr *h_attr;
 375
 376         if (nr < header->attrs) {
 377                 h_attr = header->attr[nr];
 378         } else {
 379                 h_attr = perf_header_attr__new(a);
 380                 perf_header__add_attr(header, h_attr);
 381         }
 382
 383         return h_attr;
 384 }
 385
 386 static void create_counter(int counter, int cpu, pid_t pid)
 387 {
 388         struct perf_counter_attr *attr = attrs + counter;
 389         struct perf_header_attr *h_attr;
 390         int track = !counter; /* only the first counter needs these */
 391         struct {
 392                 u64 count;
 393                 u64 time_enabled;
 394                 u64 time_running;
 395                 u64 id;
 396         } read_data;
 397
 398         attr->read_format       = PERF_FORMAT_TOTAL_TIME_ENABLED |
 399                                   PERF_FORMAT_TOTAL_TIME_RUNNING |
 400                                   PERF_FORMAT_ID;
 401
 402         attr->sample_type       |= PERF_SAMPLE_IP | PERF_SAMPLE_TID;
 403
 404         if (freq) {
 405                 attr->sample_type       |= PERF_SAMPLE_PERIOD;
 406                 attr->freq              = 1;
 407                 attr->sample_freq       = freq;
 408         }
 409
 410         if (no_samples)
 411                 attr->sample_freq = 0;
 412
 413         if (inherit_stat)
 414                 attr->inherit_stat = 1;
 415
 416         if (sample_address)
 417                 attr->sample_type       |= PERF_SAMPLE_ADDR;
 418
 419         if (call_graph)
 420                 attr->sample_type       |= PERF_SAMPLE_CALLCHAIN;
 421
 422         if (raw_samples)
 423                 attr->sample_type       |= PERF_SAMPLE_RAW;
 424
 425         attr->mmap              = track;
 426         attr->comm              = track;
 427         attr->inherit           = (cpu < 0) && inherit;
 428         attr->disabled          = 1;
 429
 430 try_again:
 431         fd[nr_cpu][counter] = sys_perf_counter_open(attr, pid, cpu, group_fd, 0);
 432
 433         if (fd[nr_cpu][counter] < 0) {
 434                 int err = errno;
 435
 436                 if (err == EPERM)
 437                         die("Permission error - are you root?\n");
 438                 else if (err ==  ENODEV && profile_cpu != -1)
 439                         die("No such device - did you specify an out-of-range profile CPU?\n");
 440
 441                 /*
 442                  * If it's cycles then fall back to hrtimer
 443                  * based cpu-clock-tick sw counter, which
 444                  * is always available even if no PMU support:
 445                  */
 446                 if (attr->type == PERF_TYPE_HARDWARE
 447                         && attr->config == PERF_COUNT_HW_CPU_CYCLES) {
 448
 449                         if (verbose)
 450                                 warning(" ... trying to fall back to cpu-clock-ticks\n");
 451                         attr->type = PERF_TYPE_SOFTWARE;
 452                         attr->config = PERF_COUNT_SW_CPU_CLOCK;
 453                         goto try_again;
 454                 }
 455                 printf("\n");
 456                 error("perfcounter syscall returned with %d (%s)\n",
 457                         fd[nr_cpu][counter], strerror(err));
 458                 die("No CONFIG_PERF_COUNTERS=y kernel support configured?\n");
 459                 exit(-1);
 460         }
 461
 462         h_attr = get_header_attr(attr, counter);
 463
 464         if (!file_new) {
 465                 if (memcmp(&h_attr->attr, attr, sizeof(*attr))) {
 466                         fprintf(stderr, "incompatible append\n");
 467                         exit(-1);
 468                 }
 469         }
 470
 471         if (read(fd[nr_cpu][counter], &read_data, sizeof(read_data)) == -1) {
 472                 perror("Unable to read perf file descriptor\n");
 473                 exit(-1);
 474         }
 475
 476         perf_header_attr__add_id(h_attr, read_data.id);
 477
 478         assert(fd[nr_cpu][counter] >= 0);
 479         fcntl(fd[nr_cpu][counter], F_SETFL, O_NONBLOCK);
 480
 481         /*
 482          * First counter acts as the group leader:
 483          */
 484         if (group && group_fd == -1)
 485                 group_fd = fd[nr_cpu][counter];
 486
 487         event_array[nr_poll].fd = fd[nr_cpu][counter];
 488         event_array[nr_poll].events = POLLIN;
 489         nr_poll++;
 490
 491         mmap_array[nr_cpu][counter].counter = counter;
 492         mmap_array[nr_cpu][counter].prev = 0;
 493         mmap_array[nr_cpu][counter].mask = mmap_pages*page_size - 1;
 494         mmap_array[nr_cpu][counter].base = mmap(NULL, (mmap_pages+1)*page_size,
 495                         PROT_READ|PROT_WRITE, MAP_SHARED, fd[nr_cpu][counter], 0);
 496         if (mmap_array[nr_cpu][counter].base == MAP_FAILED) {
 497                 error("failed to mmap with %d (%s)\n", errno, strerror(errno));
 498                 exit(-1);
 499         }
 500
 501         ioctl(fd[nr_cpu][counter], PERF_COUNTER_IOC_ENABLE);
 502 }
 503
 504 static void open_counters(int cpu, pid_t pid)
 505 {
 506         int counter;
 507
 508         group_fd = -1;
 509         for (counter = 0; counter < nr_counters; counter++)
 510                 create_counter(counter, cpu, pid);
 511
 512         nr_cpu++;
 513 }
 514
 515 static void atexit_header(void)
 516 {
 517         header->data_size += bytes_written;
 518
 519         perf_header__write(header, output);
 520 }
 521
 522 static int __cmd_record(int argc, const char **argv)
 523 {
 524         int i, counter;
 525         struct stat st;
 526         pid_t pid = 0;
 527         int flags;
 528         int ret;
 529
 530         page_size = sysconf(_SC_PAGE_SIZE);
 531         nr_cpus = sysconf(_SC_NPROCESSORS_ONLN);
 532         assert(nr_cpus <= MAX_NR_CPUS);
 533         assert(nr_cpus >= 0);
 534
 535         atexit(sig_atexit);
 536         signal(SIGCHLD, sig_handler);
 537         signal(SIGINT, sig_handler);
 538
 539         if (!stat(output_name, &st) && st.st_size) {
 540                 if (!force && !append_file) {
 541                         fprintf(stderr, "Error, output file %s exists, use -A to append or -f to overwrite.\n",
 542                                         output_name);
 543                         exit(-1);
 544                 }
 545         } else {
 546                 append_file = 0;
 547         }
 548
 549         flags = O_CREAT|O_RDWR;
 550         if (append_file)
 551                 file_new = 0;
 552         else
 553                 flags |= O_TRUNC;
 554
 555         output = open(output_name, flags, S_IRUSR|S_IWUSR);
 556         if (output < 0) {
 557                 perror("failed to create output file");
 558                 exit(-1);
 559         }
 560
 561         if (!file_new)
 562                 header = perf_header__read(output);
 563         else
 564                 header = perf_header__new();
 565
 566         atexit(atexit_header);
 567
 568         if (!system_wide) {
 569                 pid = target_pid;
 570                 if (pid == -1)
 571                         pid = getpid();
 572
 573                 open_counters(profile_cpu, pid);
 574         } else {
 575                 if (profile_cpu != -1) {
 576                         open_counters(profile_cpu, target_pid);
 577                 } else {
 578                         for (i = 0; i < nr_cpus; i++)
 579                                 open_counters(i, target_pid);
 580                 }
 581         }
 582
 583         if (file_new)
 584                 perf_header__write(header, output);
 585
 586         if (!system_wide) {
 587                 pid_t tgid = pid_synthesize_comm_event(pid, 0);
 588                 pid_synthesize_mmap_samples(pid, tgid);
 589         } else
 590                 synthesize_all();
 591
 592         if (target_pid == -1 && argc) {
 593                 pid = fork();
 594                 if (pid < 0)
 595                         perror("failed to fork");
 596
 597                 if (!pid) {
 598                         if (execvp(argv[0], (char **)argv)) {
 599                                 perror(argv[0]);
 600                                 exit(-1);
 601                         }
 602                 }
 603         }
 604
 605         if (realtime_prio) {
 606                 struct sched_param param;
 607
 608                 param.sched_priority = realtime_prio;
 609                 if (sched_setscheduler(0, SCHED_FIFO, &param)) {
 610                         printf("Could not set realtime priority.\n");
 611                         exit(-1);
 612                 }
 613         }
 614
 615         for (;;) {
 616                 int hits = samples;
 617
 618                 for (i = 0; i < nr_cpu; i++) {
 619                         for (counter = 0; counter < nr_counters; counter++)
 620                                 mmap_read(&mmap_array[i][counter]);
 621                 }
 622
 623                 if (hits == samples) {
 624                         if (done)
 625                                 break;
 626                         ret = poll(event_array, nr_poll, 100);
 627                 }
 628         }
 629
 630         /*
 631          * Approximate RIP event size: 24 bytes.
 632          */
 633         fprintf(stderr,
 634                 "[ perf record: Captured and wrote %.3f MB %s (~%lld samples) ]\n",
 635                 (double)bytes_written / 1024.0 / 1024.0,
 636                 output_name,
 637                 bytes_written / 24);
 638
 639         return 0;
 640 }
 641
 642 static const char * const record_usage[] = {
 643         "perf record [<options>] [<command>]",
 644         "perf record [<options>] -- <command> [<options>]",
 645         NULL
 646 };
 647
 648 static const struct option options[] = {
 649         OPT_CALLBACK('e', "event", NULL, "event",
 650                      "event selector. use 'perf list' to list available events",
 651                      parse_events),
 652         OPT_INTEGER('p', "pid", &target_pid,
 653                     "record events on existing pid"),
 654         OPT_INTEGER('r', "realtime", &realtime_prio,
 655                     "collect data with this RT SCHED_FIFO priority"),
 656         OPT_BOOLEAN('R', "raw-samples", &raw_samples,
 657                     "collect raw sample records from all opened counters"),
 658         OPT_BOOLEAN('a', "all-cpus", &system_wide,
 659                             "system-wide collection from all CPUs"),
 660         OPT_BOOLEAN('A', "append", &append_file,
 661                             "append to the output file to do incremental profiling"),
 662         OPT_INTEGER('C', "profile_cpu", &profile_cpu,
 663                             "CPU to profile on"),
 664         OPT_BOOLEAN('f', "force", &force,
 665                         "overwrite existing data file"),
 666         OPT_LONG('c', "count", &default_interval,
 667                     "event period to sample"),
 668         OPT_STRING('o', "output", &output_name, "file",
 669                     "output file name"),
 670         OPT_BOOLEAN('i', "inherit", &inherit,
 671                     "child tasks inherit counters"),
 672         OPT_INTEGER('F', "freq", &freq,
 673                     "profile at this frequency"),
 674         OPT_INTEGER('m', "mmap-pages", &mmap_pages,
 675                     "number of mmap data pages"),
 676         OPT_BOOLEAN('g', "call-graph", &call_graph,
 677                     "do call-graph (stack chain/backtrace) recording"),
 678         OPT_BOOLEAN('v', "verbose", &verbose,
 679                     "be more verbose (show counter open errors, etc)"),
 680         OPT_BOOLEAN('s', "stat", &inherit_stat,
 681                     "per thread counts"),
 682         OPT_BOOLEAN('d', "data", &sample_address,
 683                     "Sample addresses"),
 684         OPT_BOOLEAN('n', "no-samples", &no_samples,
 685                     "don't sample"),
 686         OPT_END()
 687 };
 688
 689 int cmd_record(int argc, const char **argv, const char *prefix __used)
 690 {
 691         int counter;
 692
 693         argc = parse_options(argc, argv, options, record_usage,
 694                 PARSE_OPT_STOP_AT_NON_OPTION);
 695         if (!argc && target_pid == -1 && !system_wide)
 696                 usage_with_options(record_usage, options);
 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         for (counter = 0; counter < nr_counters; counter++) {
 705                 if (attrs[counter].sample_period)
 706                         continue;
 707
 708                 attrs[counter].sample_period = default_interval;
 709         }
 710
 711         return __cmd_record(argc, argv);
 712 }