SAFE public projects git trees. - safe/jmp/linux-2.6/blob - 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                      inherit_stat                    = 0;
  44 static int                      no_samples                      = 0;
  45 static int                      sample_address                  = 0;
  46
  47 static long                     samples;
  48 static struct timeval           last_read;
  49 static struct timeval           this_read;
  50
  51 static u64                      bytes_written;
  52
  53 static struct pollfd            event_array[MAX_NR_CPUS * MAX_COUNTERS];
  54
  55 static int                      nr_poll;
  56 static int                      nr_cpu;
  57
  58 static int                      file_new = 1;
  59
  60 struct perf_header              *header;
  61
  62 struct mmap_data {
  63         int                     counter;
  64         void                    *base;
  65         unsigned int            mask;
  66         unsigned int            prev;
  67 };
  68
  69 static struct mmap_data         mmap_array[MAX_NR_CPUS][MAX_COUNTERS];
  70
  71 static unsigned long mmap_read_head(struct mmap_data *md)
  72 {
  73         struct perf_counter_mmap_page *pc = md->base;
  74         long head;
  75
  76         head = pc->data_head;
  77         rmb();
  78
  79         return head;
  80 }
  81
  82 static void mmap_write_tail(struct mmap_data *md, unsigned long tail)
  83 {
  84         struct perf_counter_mmap_page *pc = md->base;
  85
  86         /*
  87          * ensure all reads are done before we write the tail out.
  88          */
  89         /* mb(); */
  90         pc->data_tail = tail;
  91 }
  92
  93 static void write_output(void *buf, size_t size)
  94 {
  95         while (size) {
  96                 int ret = write(output, buf, size);
  97
  98                 if (ret < 0)
  99                         die("failed to write");
 100
 101                 size -= ret;
 102                 buf += ret;
 103
 104                 bytes_written += ret;
 105         }
 106 }
 107
 108 static void mmap_read(struct mmap_data *md)
 109 {
 110         unsigned int head = mmap_read_head(md);
 111         unsigned int old = md->prev;
 112         unsigned char *data = md->base + page_size;
 113         unsigned long size;
 114         void *buf;
 115         int diff;
 116
 117         gettimeofday(&this_read, NULL);
 118
 119         /*
 120          * If we're further behind than half the buffer, there's a chance
 121          * the writer will bite our tail and mess up the samples under us.
 122          *
 123          * If we somehow ended up ahead of the head, we got messed up.
 124          *
 125          * In either case, truncate and restart at head.
 126          */
 127         diff = head - old;
 128         if (diff < 0) {
 129                 struct timeval iv;
 130                 unsigned long msecs;
 131
 132                 timersub(&this_read, &last_read, &iv);
 133                 msecs = iv.tv_sec*1000 + iv.tv_usec/1000;
 134
 135                 fprintf(stderr, "WARNING: failed to keep up with mmap data."
 136                                 "  Last read %lu msecs ago.\n", msecs);
 137
 138                 /*
 139                  * head points to a known good entry, start there.
 140                  */
 141                 old = head;
 142         }
 143
 144         last_read = this_read;
 145
 146         if (old != head)
 147                 samples++;
 148
 149         size = head - old;
 150
 151         if ((old & md->mask) + size != (head & md->mask)) {
 152                 buf = &data[old & md->mask];
 153                 size = md->mask + 1 - (old & md->mask);
 154                 old += size;
 155
 156                 write_output(buf, size);
 157         }
 158
 159         buf = &data[old & md->mask];
 160         size = head - old;
 161         old += size;
 162
 163         write_output(buf, size);
 164
 165         md->prev = old;
 166         mmap_write_tail(md, old);
 167 }
 168
 169 static volatile int done = 0;
 170 static volatile int signr = -1;
 171
 172 static void sig_handler(int sig)
 173 {
 174         done = 1;
 175         signr = sig;
 176 }
 177
 178 static void sig_atexit(void)
 179 {
 180         if (signr == -1)
 181                 return;
 182
 183         signal(signr, SIG_DFL);
 184         kill(getpid(), signr);
 185 }
 186
 187 static void pid_synthesize_comm_event(pid_t pid, int full)
 188 {
 189         struct comm_event comm_ev;
 190         char filename[PATH_MAX];
 191         char bf[BUFSIZ];
 192         int fd;
 193         size_t size;
 194         char *field, *sep;
 195         DIR *tasks;
 196         struct dirent dirent, *next;
 197
 198         snprintf(filename, sizeof(filename), "/proc/%d/stat", pid);
 199
 200         fd = open(filename, O_RDONLY);
 201         if (fd < 0) {
 202                 /*
 203                  * We raced with a task exiting - just return:
 204                  */
 205                 if (verbose)
 206                         fprintf(stderr, "couldn't open %s\n", filename);
 207                 return;
 208         }
 209         if (read(fd, bf, sizeof(bf)) < 0) {
 210                 fprintf(stderr, "couldn't read %s\n", filename);
 211                 exit(EXIT_FAILURE);
 212         }
 213         close(fd);
 214
 215         /* 9027 (cat) R 6747 9027 6747 34816 9027 ... */
 216         memset(&comm_ev, 0, sizeof(comm_ev));
 217         field = strchr(bf, '(');
 218         if (field == NULL)
 219                 goto out_failure;
 220         sep = strchr(++field, ')');
 221         if (sep == NULL)
 222                 goto out_failure;
 223         size = sep - field;
 224         memcpy(comm_ev.comm, field, size++);
 225
 226         comm_ev.pid = pid;
 227         comm_ev.header.type = PERF_EVENT_COMM;
 228         size = ALIGN(size, sizeof(u64));
 229         comm_ev.header.size = sizeof(comm_ev) - (sizeof(comm_ev.comm) - size);
 230
 231         if (!full) {
 232                 comm_ev.tid = pid;
 233
 234                 write_output(&comm_ev, comm_ev.header.size);
 235                 return;
 236         }
 237
 238         snprintf(filename, sizeof(filename), "/proc/%d/task", pid);
 239
 240         tasks = opendir(filename);
 241         while (!readdir_r(tasks, &dirent, &next) && next) {
 242                 char *end;
 243                 pid = strtol(dirent.d_name, &end, 10);
 244                 if (*end)
 245                         continue;
 246
 247                 comm_ev.tid = pid;
 248
 249                 write_output(&comm_ev, comm_ev.header.size);
 250         }
 251         closedir(tasks);
 252         return;
 253
 254 out_failure:
 255         fprintf(stderr, "couldn't get COMM and pgid, malformed %s\n",
 256                 filename);
 257         exit(EXIT_FAILURE);
 258 }
 259
 260 static void pid_synthesize_mmap_samples(pid_t pid)
 261 {
 262         char filename[PATH_MAX];
 263         FILE *fp;
 264
 265         snprintf(filename, sizeof(filename), "/proc/%d/maps", pid);
 266
 267         fp = fopen(filename, "r");
 268         if (fp == NULL) {
 269                 /*
 270                  * We raced with a task exiting - just return:
 271                  */
 272                 if (verbose)
 273                         fprintf(stderr, "couldn't open %s\n", filename);
 274                 return;
 275         }
 276         while (1) {
 277                 char bf[BUFSIZ], *pbf = bf;
 278                 struct mmap_event mmap_ev = {
 279                         .header = { .type = PERF_EVENT_MMAP },
 280                 };
 281                 int n;
 282                 size_t size;
 283                 if (fgets(bf, sizeof(bf), fp) == NULL)
 284                         break;
 285
 286                 /* 00400000-0040c000 r-xp 00000000 fd:01 41038  /bin/cat */
 287                 n = hex2u64(pbf, &mmap_ev.start);
 288                 if (n < 0)
 289                         continue;
 290                 pbf += n + 1;
 291                 n = hex2u64(pbf, &mmap_ev.len);
 292                 if (n < 0)
 293                         continue;
 294                 pbf += n + 3;
 295                 if (*pbf == 'x') { /* vm_exec */
 296                         char *execname = strchr(bf, '/');
 297
 298                         /* Catch VDSO */
 299                         if (execname == NULL)
 300                                 execname = strstr(bf, "[vdso]");
 301
 302                         if (execname == NULL)
 303                                 continue;
 304
 305                         size = strlen(execname);
 306                         execname[size - 1] = '\0'; /* Remove \n */
 307                         memcpy(mmap_ev.filename, execname, size);
 308                         size = ALIGN(size, sizeof(u64));
 309                         mmap_ev.len -= mmap_ev.start;
 310                         mmap_ev.header.size = (sizeof(mmap_ev) -
 311                                                (sizeof(mmap_ev.filename) - size));
 312                         mmap_ev.pid = pid;
 313                         mmap_ev.tid = pid;
 314
 315                         write_output(&mmap_ev, mmap_ev.header.size);
 316                 }
 317         }
 318
 319         fclose(fp);
 320 }
 321
 322 static void synthesize_all(void)
 323 {
 324         DIR *proc;
 325         struct dirent dirent, *next;
 326
 327         proc = opendir("/proc");
 328
 329         while (!readdir_r(proc, &dirent, &next) && next) {
 330                 char *end;
 331                 pid_t pid;
 332
 333                 pid = strtol(dirent.d_name, &end, 10);
 334                 if (*end) /* only interested in proper numerical dirents */
 335                         continue;
 336
 337                 pid_synthesize_comm_event(pid, 1);
 338                 pid_synthesize_mmap_samples(pid);
 339         }
 340
 341         closedir(proc);
 342 }
 343
 344 static int group_fd;
 345
 346 static struct perf_header_attr *get_header_attr(struct perf_counter_attr *a, int nr)
 347 {
 348         struct perf_header_attr *h_attr;
 349
 350         if (nr < header->attrs) {
 351                 h_attr = header->attr[nr];
 352         } else {
 353                 h_attr = perf_header_attr__new(a);
 354                 perf_header__add_attr(header, h_attr);
 355         }
 356
 357         return h_attr;
 358 }
 359
 360 static void create_counter(int counter, int cpu, pid_t pid)
 361 {
 362         struct perf_counter_attr *attr = attrs + counter;
 363         struct perf_header_attr *h_attr;
 364         int track = !counter; /* only the first counter needs these */
 365         struct {
 366                 u64 count;
 367                 u64 time_enabled;
 368                 u64 time_running;
 369                 u64 id;
 370         } read_data;
 371
 372         attr->read_format       = PERF_FORMAT_TOTAL_TIME_ENABLED |
 373                                   PERF_FORMAT_TOTAL_TIME_RUNNING |
 374                                   PERF_FORMAT_ID;
 375
 376         attr->sample_type       = PERF_SAMPLE_IP | PERF_SAMPLE_TID;
 377
 378         if (freq) {
 379                 attr->sample_type       |= PERF_SAMPLE_PERIOD;
 380                 attr->freq              = 1;
 381                 attr->sample_freq       = freq;
 382         }
 383
 384         if (no_samples)
 385                 attr->sample_freq = 0;
 386
 387         if (inherit_stat)
 388                 attr->inherit_stat = 1;
 389
 390         if (sample_address)
 391                 attr->sample_type       |= PERF_SAMPLE_ADDR;
 392
 393         if (call_graph)
 394                 attr->sample_type       |= PERF_SAMPLE_CALLCHAIN;
 395
 396
 397         attr->mmap              = track;
 398         attr->comm              = track;
 399         attr->inherit           = (cpu < 0) && inherit;
 400         attr->disabled          = 1;
 401
 402 try_again:
 403         fd[nr_cpu][counter] = sys_perf_counter_open(attr, pid, cpu, group_fd, 0);
 404
 405         if (fd[nr_cpu][counter] < 0) {
 406                 int err = errno;
 407
 408                 if (err == EPERM)
 409                         die("Permission error - are you root?\n");
 410
 411                 /*
 412                  * If it's cycles then fall back to hrtimer
 413                  * based cpu-clock-tick sw counter, which
 414                  * is always available even if no PMU support:
 415                  */
 416                 if (attr->type == PERF_TYPE_HARDWARE
 417                         && attr->config == PERF_COUNT_HW_CPU_CYCLES) {
 418
 419                         if (verbose)
 420                                 warning(" ... trying to fall back to cpu-clock-ticks\n");
 421                         attr->type = PERF_TYPE_SOFTWARE;
 422                         attr->config = PERF_COUNT_SW_CPU_CLOCK;
 423                         goto try_again;
 424                 }
 425                 printf("\n");
 426                 error("perfcounter syscall returned with %d (%s)\n",
 427                         fd[nr_cpu][counter], strerror(err));
 428                 die("No CONFIG_PERF_COUNTERS=y kernel support configured?\n");
 429                 exit(-1);
 430         }
 431
 432         h_attr = get_header_attr(attr, counter);
 433
 434         if (!file_new) {
 435                 if (memcmp(&h_attr->attr, attr, sizeof(*attr))) {
 436                         fprintf(stderr, "incompatible append\n");
 437                         exit(-1);
 438                 }
 439         }
 440
 441         if (read(fd[nr_cpu][counter], &read_data, sizeof(read_data)) == -1) {
 442                 perror("Unable to read perf file descriptor\n");
 443                 exit(-1);
 444         }
 445
 446         perf_header_attr__add_id(h_attr, read_data.id);
 447
 448         assert(fd[nr_cpu][counter] >= 0);
 449         fcntl(fd[nr_cpu][counter], F_SETFL, O_NONBLOCK);
 450
 451         /*
 452          * First counter acts as the group leader:
 453          */
 454         if (group && group_fd == -1)
 455                 group_fd = fd[nr_cpu][counter];
 456
 457         event_array[nr_poll].fd = fd[nr_cpu][counter];
 458         event_array[nr_poll].events = POLLIN;
 459         nr_poll++;
 460
 461         mmap_array[nr_cpu][counter].counter = counter;
 462         mmap_array[nr_cpu][counter].prev = 0;
 463         mmap_array[nr_cpu][counter].mask = mmap_pages*page_size - 1;
 464         mmap_array[nr_cpu][counter].base = mmap(NULL, (mmap_pages+1)*page_size,
 465                         PROT_READ|PROT_WRITE, MAP_SHARED, fd[nr_cpu][counter], 0);
 466         if (mmap_array[nr_cpu][counter].base == MAP_FAILED) {
 467                 error("failed to mmap with %d (%s)\n", errno, strerror(errno));
 468                 exit(-1);
 469         }
 470
 471         ioctl(fd[nr_cpu][counter], PERF_COUNTER_IOC_ENABLE);
 472 }
 473
 474 static void open_counters(int cpu, pid_t pid)
 475 {
 476         int counter;
 477
 478         group_fd = -1;
 479         for (counter = 0; counter < nr_counters; counter++)
 480                 create_counter(counter, cpu, pid);
 481
 482         nr_cpu++;
 483 }
 484
 485 static void atexit_header(void)
 486 {
 487         header->data_size += bytes_written;
 488
 489         perf_header__write(header, output);
 490 }
 491
 492 static int __cmd_record(int argc, const char **argv)
 493 {
 494         int i, counter;
 495         struct stat st;
 496         pid_t pid = 0;
 497         int flags;
 498         int ret;
 499
 500         page_size = sysconf(_SC_PAGE_SIZE);
 501         nr_cpus = sysconf(_SC_NPROCESSORS_ONLN);
 502         assert(nr_cpus <= MAX_NR_CPUS);
 503         assert(nr_cpus >= 0);
 504
 505         atexit(sig_atexit);
 506         signal(SIGCHLD, sig_handler);
 507         signal(SIGINT, sig_handler);
 508
 509         if (!stat(output_name, &st) && st.st_size) {
 510                 if (!force && !append_file) {
 511                         fprintf(stderr, "Error, output file %s exists, use -A to append or -f to overwrite.\n",
 512                                         output_name);
 513                         exit(-1);
 514                 }
 515         } else {
 516                 append_file = 0;
 517         }
 518
 519         flags = O_CREAT|O_RDWR;
 520         if (append_file)
 521                 file_new = 0;
 522         else
 523                 flags |= O_TRUNC;
 524
 525         output = open(output_name, flags, S_IRUSR|S_IWUSR);
 526         if (output < 0) {
 527                 perror("failed to create output file");
 528                 exit(-1);
 529         }
 530
 531         if (!file_new)
 532                 header = perf_header__read(output);
 533         else
 534                 header = perf_header__new();
 535
 536         atexit(atexit_header);
 537
 538         if (!system_wide) {
 539                 pid = target_pid;
 540                 if (pid == -1)
 541                         pid = getpid();
 542
 543                 open_counters(-1, pid);
 544         } else for (i = 0; i < nr_cpus; i++)
 545                 open_counters(i, target_pid);
 546
 547         if (file_new)
 548                 perf_header__write(header, output);
 549
 550         if (!system_wide) {
 551                 pid_synthesize_comm_event(pid, 0);
 552                 pid_synthesize_mmap_samples(pid);
 553         } else
 554                 synthesize_all();
 555
 556         if (target_pid == -1 && argc) {
 557                 pid = fork();
 558                 if (pid < 0)
 559                         perror("failed to fork");
 560
 561                 if (!pid) {
 562                         if (execvp(argv[0], (char **)argv)) {
 563                                 perror(argv[0]);
 564                                 exit(-1);
 565                         }
 566                 }
 567         }
 568
 569         if (realtime_prio) {
 570                 struct sched_param param;
 571
 572                 param.sched_priority = realtime_prio;
 573                 if (sched_setscheduler(0, SCHED_FIFO, &param)) {
 574                         printf("Could not set realtime priority.\n");
 575                         exit(-1);
 576                 }
 577         }
 578
 579         for (;;) {
 580                 int hits = samples;
 581
 582                 for (i = 0; i < nr_cpu; i++) {
 583                         for (counter = 0; counter < nr_counters; counter++)
 584                                 mmap_read(&mmap_array[i][counter]);
 585                 }
 586
 587                 if (hits == samples) {
 588                         if (done)
 589                                 break;
 590                         ret = poll(event_array, nr_poll, 100);
 591                 }
 592         }
 593
 594         /*
 595          * Approximate RIP event size: 24 bytes.
 596          */
 597         fprintf(stderr,
 598                 "[ perf record: Captured and wrote %.3f MB %s (~%lld samples) ]\n",
 599                 (double)bytes_written / 1024.0 / 1024.0,
 600                 output_name,
 601                 bytes_written / 24);
 602
 603         return 0;
 604 }
 605
 606 static const char * const record_usage[] = {
 607         "perf record [<options>] [<command>]",
 608         "perf record [<options>] -- <command> [<options>]",
 609         NULL
 610 };
 611
 612 static const struct option options[] = {
 613         OPT_CALLBACK('e', "event", NULL, "event",
 614                      "event selector. use 'perf list' to list available events",
 615                      parse_events),
 616         OPT_INTEGER('p', "pid", &target_pid,
 617                     "record events on existing pid"),
 618         OPT_INTEGER('r', "realtime", &realtime_prio,
 619                     "collect data with this RT SCHED_FIFO priority"),
 620         OPT_BOOLEAN('a', "all-cpus", &system_wide,
 621                             "system-wide collection from all CPUs"),
 622         OPT_BOOLEAN('A', "append", &append_file,
 623                             "append to the output file to do incremental profiling"),
 624         OPT_BOOLEAN('f', "force", &force,
 625                         "overwrite existing data file"),
 626         OPT_LONG('c', "count", &default_interval,
 627                     "event period to sample"),
 628         OPT_STRING('o', "output", &output_name, "file",
 629                     "output file name"),
 630         OPT_BOOLEAN('i', "inherit", &inherit,
 631                     "child tasks inherit counters"),
 632         OPT_INTEGER('F', "freq", &freq,
 633                     "profile at this frequency"),
 634         OPT_INTEGER('m', "mmap-pages", &mmap_pages,
 635                     "number of mmap data pages"),
 636         OPT_BOOLEAN('g', "call-graph", &call_graph,
 637                     "do call-graph (stack chain/backtrace) recording"),
 638         OPT_BOOLEAN('v', "verbose", &verbose,
 639                     "be more verbose (show counter open errors, etc)"),
 640         OPT_BOOLEAN('s', "stat", &inherit_stat,
 641                     "per thread counts"),
 642         OPT_BOOLEAN('d', "data", &sample_address,
 643                     "Sample addresses"),
 644         OPT_BOOLEAN('n', "no-samples", &no_samples,
 645                     "don't sample"),
 646         OPT_END()
 647 };
 648
 649 int cmd_record(int argc, const char **argv, const char *prefix __used)
 650 {
 651         int counter;
 652
 653         argc = parse_options(argc, argv, options, record_usage,
 654                 PARSE_OPT_STOP_AT_NON_OPTION);
 655         if (!argc && target_pid == -1 && !system_wide)
 656                 usage_with_options(record_usage, options);
 657
 658         if (!nr_counters) {
 659                 nr_counters     = 1;
 660                 attrs[0].type   = PERF_TYPE_HARDWARE;
 661                 attrs[0].config = PERF_COUNT_HW_CPU_CYCLES;
 662         }
 663
 664         for (counter = 0; counter < nr_counters; counter++) {
 665                 if (attrs[counter].sample_period)
 666                         continue;
 667
 668                 attrs[counter].sample_period = default_interval;
 669         }
 670
 671         return __cmd_record(argc, argv);
 672 }