git.oblomov.eu Git - 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 <unistd.h>
  18 #include <sched.h>
  19
  20 #define ALIGN(x, a)             __ALIGN_MASK(x, (typeof(x))(a)-1)
  21 #define __ALIGN_MASK(x, mask)   (((x)+(mask))&~(mask))
  22
  23 static int                      fd[MAX_NR_CPUS][MAX_COUNTERS];
  24
  25 static long                     default_interval                = 100000;
  26
  27 static int                      nr_cpus                         = 0;
  28 static unsigned int             page_size;
  29 static unsigned int             mmap_pages                      = 128;
  30 static int                      freq                            = 0;
  31 static int                      output;
  32 static const char               *output_name                    = "perf.data";
  33 static int                      group                           = 0;
  34 static unsigned int             realtime_prio                   = 0;
  35 static int                      system_wide                     = 0;
  36 static pid_t                    target_pid                      = -1;
  37 static int                      inherit                         = 1;
  38 static int                      force                           = 0;
  39 static int                      append_file                     = 0;
  40 static int                      call_graph                      = 0;
  41 static int                      verbose                         = 0;
  42
  43 static long                     samples;
  44 static struct timeval           last_read;
  45 static struct timeval           this_read;
  46
  47 static __u64                    bytes_written;
  48
  49 static struct pollfd            event_array[MAX_NR_CPUS * MAX_COUNTERS];
  50
  51 static int                      nr_poll;
  52 static int                      nr_cpu;
  53
  54 struct mmap_event {
  55         struct perf_event_header        header;
  56         __u32                           pid;
  57         __u32                           tid;
  58         __u64                           start;
  59         __u64                           len;
  60         __u64                           pgoff;
  61         char                            filename[PATH_MAX];
  62 };
  63
  64 struct comm_event {
  65         struct perf_event_header        header;
  66         __u32                           pid;
  67         __u32                           tid;
  68         char                            comm[16];
  69 };
  70
  71
  72 struct mmap_data {
  73         int                     counter;
  74         void                    *base;
  75         unsigned int            mask;
  76         unsigned int            prev;
  77 };
  78
  79 static struct mmap_data         mmap_array[MAX_NR_CPUS][MAX_COUNTERS];
  80
  81 static unsigned int mmap_read_head(struct mmap_data *md)
  82 {
  83         struct perf_counter_mmap_page *pc = md->base;
  84         int head;
  85
  86         head = pc->data_head;
  87         rmb();
  88
  89         return head;
  90 }
  91
  92 static void mmap_read(struct mmap_data *md)
  93 {
  94         unsigned int head = mmap_read_head(md);
  95         unsigned int old = md->prev;
  96         unsigned char *data = md->base + page_size;
  97         unsigned long size;
  98         void *buf;
  99         int diff;
 100
 101         gettimeofday(&this_read, NULL);
 102
 103         /*
 104          * If we're further behind than half the buffer, there's a chance
 105          * the writer will bite our tail and mess up the samples under us.
 106          *
 107          * If we somehow ended up ahead of the head, we got messed up.
 108          *
 109          * In either case, truncate and restart at head.
 110          */
 111         diff = head - old;
 112         if (diff > md->mask / 2 || diff < 0) {
 113                 struct timeval iv;
 114                 unsigned long msecs;
 115
 116                 timersub(&this_read, &last_read, &iv);
 117                 msecs = iv.tv_sec*1000 + iv.tv_usec/1000;
 118
 119                 fprintf(stderr, "WARNING: failed to keep up with mmap data."
 120                                 "  Last read %lu msecs ago.\n", msecs);
 121
 122                 /*
 123                  * head points to a known good entry, start there.
 124                  */
 125                 old = head;
 126         }
 127
 128         last_read = this_read;
 129
 130         if (old != head)
 131                 samples++;
 132
 133         size = head - old;
 134
 135         if ((old & md->mask) + size != (head & md->mask)) {
 136                 buf = &data[old & md->mask];
 137                 size = md->mask + 1 - (old & md->mask);
 138                 old += size;
 139
 140                 while (size) {
 141                         int ret = write(output, buf, size);
 142
 143                         if (ret < 0)
 144                                 die("failed to write");
 145
 146                         size -= ret;
 147                         buf += ret;
 148
 149                         bytes_written += ret;
 150                 }
 151         }
 152
 153         buf = &data[old & md->mask];
 154         size = head - old;
 155         old += size;
 156
 157         while (size) {
 158                 int ret = write(output, buf, size);
 159
 160                 if (ret < 0)
 161                         die("failed to write");
 162
 163                 size -= ret;
 164                 buf += ret;
 165
 166                 bytes_written += ret;
 167         }
 168
 169         md->prev = old;
 170 }
 171
 172 static volatile int done = 0;
 173 static volatile int signr = -1;
 174
 175 static void sig_handler(int sig)
 176 {
 177         done = 1;
 178         signr = sig;
 179 }
 180
 181 static void sig_atexit(void)
 182 {
 183         if (signr == -1)
 184                 return;
 185
 186         signal(signr, SIG_DFL);
 187         kill(getpid(), signr);
 188 }
 189
 190 static void pid_synthesize_comm_event(pid_t pid, int full)
 191 {
 192         struct comm_event comm_ev;
 193         char filename[PATH_MAX];
 194         char bf[BUFSIZ];
 195         int fd, ret;
 196         size_t size;
 197         char *field, *sep;
 198         DIR *tasks;
 199         struct dirent dirent, *next;
 200
 201         snprintf(filename, sizeof(filename), "/proc/%d/stat", pid);
 202
 203         fd = open(filename, O_RDONLY);
 204         if (fd < 0) {
 205                 /*
 206                  * We raced with a task exiting - just return:
 207                  */
 208                 if (verbose)
 209                         fprintf(stderr, "couldn't open %s\n", filename);
 210                 return;
 211         }
 212         if (read(fd, bf, sizeof(bf)) < 0) {
 213                 fprintf(stderr, "couldn't read %s\n", filename);
 214                 exit(EXIT_FAILURE);
 215         }
 216         close(fd);
 217
 218         /* 9027 (cat) R 6747 9027 6747 34816 9027 ... */
 219         memset(&comm_ev, 0, sizeof(comm_ev));
 220         field = strchr(bf, '(');
 221         if (field == NULL)
 222                 goto out_failure;
 223         sep = strchr(++field, ')');
 224         if (sep == NULL)
 225                 goto out_failure;
 226         size = sep - field;
 227         memcpy(comm_ev.comm, field, size++);
 228
 229         comm_ev.pid = pid;
 230         comm_ev.header.type = PERF_EVENT_COMM;
 231         size = ALIGN(size, sizeof(__u64));
 232         comm_ev.header.size = sizeof(comm_ev) - (sizeof(comm_ev.comm) - size);
 233
 234         if (!full) {
 235                 comm_ev.tid = pid;
 236
 237                 ret = write(output, &comm_ev, comm_ev.header.size);
 238                 if (ret < 0) {
 239                         perror("failed to write");
 240                         exit(-1);
 241                 }
 242                 return;
 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                 ret = write(output, &comm_ev, comm_ev.header.size);
 257                 if (ret < 0) {
 258                         perror("failed to write");
 259                         exit(-1);
 260                 }
 261         }
 262         closedir(tasks);
 263         return;
 264
 265 out_failure:
 266         fprintf(stderr, "couldn't get COMM and pgid, malformed %s\n",
 267                 filename);
 268         exit(EXIT_FAILURE);
 269 }
 270
 271 static void pid_synthesize_mmap_samples(pid_t pid)
 272 {
 273         char filename[PATH_MAX];
 274         FILE *fp;
 275
 276         snprintf(filename, sizeof(filename), "/proc/%d/maps", pid);
 277
 278         fp = fopen(filename, "r");
 279         if (fp == NULL) {
 280                 /*
 281                  * We raced with a task exiting - just return:
 282                  */
 283                 if (verbose)
 284                         fprintf(stderr, "couldn't open %s\n", filename);
 285                 return;
 286         }
 287         while (1) {
 288                 char bf[BUFSIZ], *pbf = bf;
 289                 struct mmap_event mmap_ev = {
 290                         .header.type = PERF_EVENT_MMAP,
 291                 };
 292                 int n;
 293                 size_t size;
 294                 if (fgets(bf, sizeof(bf), fp) == NULL)
 295                         break;
 296
 297                 /* 00400000-0040c000 r-xp 00000000 fd:01 41038  /bin/cat */
 298                 n = hex2u64(pbf, &mmap_ev.start);
 299                 if (n < 0)
 300                         continue;
 301                 pbf += n + 1;
 302                 n = hex2u64(pbf, &mmap_ev.len);
 303                 if (n < 0)
 304                         continue;
 305                 pbf += n + 3;
 306                 if (*pbf == 'x') { /* vm_exec */
 307                         char *execname = strrchr(bf, ' ');
 308
 309                         if (execname == NULL || execname[1] != '/')
 310                                 continue;
 311
 312                         execname += 1;
 313                         size = strlen(execname);
 314                         execname[size - 1] = '\0'; /* Remove \n */
 315                         memcpy(mmap_ev.filename, execname, size);
 316                         size = ALIGN(size, sizeof(__u64));
 317                         mmap_ev.len -= mmap_ev.start;
 318                         mmap_ev.header.size = (sizeof(mmap_ev) -
 319                                                (sizeof(mmap_ev.filename) - size));
 320                         mmap_ev.pid = pid;
 321                         mmap_ev.tid = pid;
 322
 323                         if (write(output, &mmap_ev, mmap_ev.header.size) < 0) {
 324                                 perror("failed to write");
 325                                 exit(-1);
 326                         }
 327                 }
 328         }
 329
 330         fclose(fp);
 331 }
 332
 333 static void synthesize_samples(void)
 334 {
 335         DIR *proc;
 336         struct dirent dirent, *next;
 337
 338         proc = opendir("/proc");
 339
 340         while (!readdir_r(proc, &dirent, &next) && next) {
 341                 char *end;
 342                 pid_t pid;
 343
 344                 pid = strtol(dirent.d_name, &end, 10);
 345                 if (*end) /* only interested in proper numerical dirents */
 346                         continue;
 347
 348                 pid_synthesize_comm_event(pid, 1);
 349                 pid_synthesize_mmap_samples(pid);
 350         }
 351
 352         closedir(proc);
 353 }
 354
 355 static int group_fd;
 356
 357 static void create_counter(int counter, int cpu, pid_t pid)
 358 {
 359         struct perf_counter_attr *attr = attrs + counter;
 360         int track = 1;
 361
 362         attr->sample_type       = PERF_SAMPLE_IP | PERF_SAMPLE_TID;
 363
 364         if (freq) {
 365                 attr->sample_type       |= PERF_SAMPLE_PERIOD;
 366                 attr->freq              = 1;
 367                 attr->sample_freq       = freq;
 368         }
 369
 370         if (call_graph)
 371                 attr->sample_type       |= PERF_SAMPLE_CALLCHAIN;
 372
 373         attr->mmap              = track;
 374         attr->comm              = track;
 375         attr->inherit           = (cpu < 0) && inherit;
 376         attr->disabled          = 1;
 377
 378         track = 0; /* only the first counter needs these */
 379
 380 try_again:
 381         fd[nr_cpu][counter] = sys_perf_counter_open(attr, pid, cpu, group_fd, 0);
 382
 383         if (fd[nr_cpu][counter] < 0) {
 384                 int err = errno;
 385
 386                 if (err == EPERM)
 387                         die("Permission error - are you root?\n");
 388
 389                 /*
 390                  * If it's cycles then fall back to hrtimer
 391                  * based cpu-clock-tick sw counter, which
 392                  * is always available even if no PMU support:
 393                  */
 394                 if (attr->type == PERF_TYPE_HARDWARE
 395                         && attr->config == PERF_COUNT_HW_CPU_CYCLES) {
 396
 397                         if (verbose)
 398                                 warning(" ... trying to fall back to cpu-clock-ticks\n");
 399                         attr->type = PERF_TYPE_SOFTWARE;
 400                         attr->config = PERF_COUNT_SW_CPU_CLOCK;
 401                         goto try_again;
 402                 }
 403                 printf("\n");
 404                 error("perfcounter syscall returned with %d (%s)\n",
 405                         fd[nr_cpu][counter], strerror(err));
 406                 die("No CONFIG_PERF_COUNTERS=y kernel support configured?\n");
 407                 exit(-1);
 408         }
 409
 410         assert(fd[nr_cpu][counter] >= 0);
 411         fcntl(fd[nr_cpu][counter], F_SETFL, O_NONBLOCK);
 412
 413         /*
 414          * First counter acts as the group leader:
 415          */
 416         if (group && group_fd == -1)
 417                 group_fd = fd[nr_cpu][counter];
 418
 419         event_array[nr_poll].fd = fd[nr_cpu][counter];
 420         event_array[nr_poll].events = POLLIN;
 421         nr_poll++;
 422
 423         mmap_array[nr_cpu][counter].counter = counter;
 424         mmap_array[nr_cpu][counter].prev = 0;
 425         mmap_array[nr_cpu][counter].mask = mmap_pages*page_size - 1;
 426         mmap_array[nr_cpu][counter].base = mmap(NULL, (mmap_pages+1)*page_size,
 427                         PROT_READ, MAP_SHARED, fd[nr_cpu][counter], 0);
 428         if (mmap_array[nr_cpu][counter].base == MAP_FAILED) {
 429                 error("failed to mmap with %d (%s)\n", errno, strerror(errno));
 430                 exit(-1);
 431         }
 432
 433         ioctl(fd[nr_cpu][counter], PERF_COUNTER_IOC_ENABLE);
 434 }
 435
 436 static void open_counters(int cpu, pid_t pid)
 437 {
 438         int counter;
 439
 440         if (pid > 0) {
 441                 pid_synthesize_comm_event(pid, 0);
 442                 pid_synthesize_mmap_samples(pid);
 443         }
 444
 445         group_fd = -1;
 446         for (counter = 0; counter < nr_counters; counter++)
 447                 create_counter(counter, cpu, pid);
 448
 449         nr_cpu++;
 450 }
 451
 452 static int __cmd_record(int argc, const char **argv)
 453 {
 454         int i, counter;
 455         struct stat st;
 456         pid_t pid;
 457         int flags;
 458         int ret;
 459
 460         page_size = sysconf(_SC_PAGE_SIZE);
 461         nr_cpus = sysconf(_SC_NPROCESSORS_ONLN);
 462         assert(nr_cpus <= MAX_NR_CPUS);
 463         assert(nr_cpus >= 0);
 464
 465         if (!stat(output_name, &st) && !force && !append_file) {
 466                 fprintf(stderr, "Error, output file %s exists, use -A to append or -f to overwrite.\n",
 467                                 output_name);
 468                 exit(-1);
 469         }
 470
 471         flags = O_CREAT|O_RDWR;
 472         if (append_file)
 473                 flags |= O_APPEND;
 474         else
 475                 flags |= O_TRUNC;
 476
 477         output = open(output_name, flags, S_IRUSR|S_IWUSR);
 478         if (output < 0) {
 479                 perror("failed to create output file");
 480                 exit(-1);
 481         }
 482
 483         if (!system_wide) {
 484                 open_counters(-1, target_pid != -1 ? target_pid : getpid());
 485         } else for (i = 0; i < nr_cpus; i++)
 486                 open_counters(i, target_pid);
 487
 488         atexit(sig_atexit);
 489         signal(SIGCHLD, sig_handler);
 490         signal(SIGINT, sig_handler);
 491
 492         if (target_pid == -1 && argc) {
 493                 pid = fork();
 494                 if (pid < 0)
 495                         perror("failed to fork");
 496
 497                 if (!pid) {
 498                         if (execvp(argv[0], (char **)argv)) {
 499                                 perror(argv[0]);
 500                                 exit(-1);
 501                         }
 502                 }
 503         }
 504
 505         if (realtime_prio) {
 506                 struct sched_param param;
 507
 508                 param.sched_priority = realtime_prio;
 509                 if (sched_setscheduler(0, SCHED_FIFO, &param)) {
 510                         printf("Could not set realtime priority.\n");
 511                         exit(-1);
 512                 }
 513         }
 514
 515         if (system_wide)
 516                 synthesize_samples();
 517
 518         while (!done) {
 519                 int hits = samples;
 520
 521                 for (i = 0; i < nr_cpu; i++) {
 522                         for (counter = 0; counter < nr_counters; counter++)
 523                                 mmap_read(&mmap_array[i][counter]);
 524                 }
 525
 526                 if (hits == samples)
 527                         ret = poll(event_array, nr_poll, 100);
 528         }
 529
 530         /*
 531          * Approximate RIP event size: 24 bytes.
 532          */
 533         fprintf(stderr,
 534                 "[ perf record: Captured and wrote %.3f MB %s (~%lld samples) ]\n",
 535                 (double)bytes_written / 1024.0 / 1024.0,
 536                 output_name,
 537                 bytes_written / 24);
 538
 539         return 0;
 540 }
 541
 542 static const char * const record_usage[] = {
 543         "perf record [<options>] [<command>]",
 544         "perf record [<options>] -- <command> [<options>]",
 545         NULL
 546 };
 547
 548 static const struct option options[] = {
 549         OPT_CALLBACK('e', "event", NULL, "event",
 550                      "event selector. use 'perf list' to list available events",
 551                      parse_events),
 552         OPT_INTEGER('p', "pid", &target_pid,
 553                     "record events on existing pid"),
 554         OPT_INTEGER('r', "realtime", &realtime_prio,
 555                     "collect data with this RT SCHED_FIFO priority"),
 556         OPT_BOOLEAN('a', "all-cpus", &system_wide,
 557                             "system-wide collection from all CPUs"),
 558         OPT_BOOLEAN('A', "append", &append_file,
 559                             "append to the output file to do incremental profiling"),
 560         OPT_BOOLEAN('f', "force", &force,
 561                         "overwrite existing data file"),
 562         OPT_LONG('c', "count", &default_interval,
 563                     "event period to sample"),
 564         OPT_STRING('o', "output", &output_name, "file",
 565                     "output file name"),
 566         OPT_BOOLEAN('i', "inherit", &inherit,
 567                     "child tasks inherit counters"),
 568         OPT_INTEGER('F', "freq", &freq,
 569                     "profile at this frequency"),
 570         OPT_INTEGER('m', "mmap-pages", &mmap_pages,
 571                     "number of mmap data pages"),
 572         OPT_BOOLEAN('g', "call-graph", &call_graph,
 573                     "do call-graph (stack chain/backtrace) recording"),
 574         OPT_BOOLEAN('v', "verbose", &verbose,
 575                     "be more verbose (show counter open errors, etc)"),
 576         OPT_END()
 577 };
 578
 579 int cmd_record(int argc, const char **argv, const char *prefix)
 580 {
 581         int counter;
 582
 583         argc = parse_options(argc, argv, options, record_usage, 0);
 584         if (!argc && target_pid == -1 && !system_wide)
 585                 usage_with_options(record_usage, options);
 586
 587         if (!nr_counters) {
 588                 nr_counters     = 1;
 589                 attrs[0].type   = PERF_TYPE_HARDWARE;
 590                 attrs[0].config = PERF_COUNT_HW_CPU_CYCLES;
 591         }
 592
 593         for (counter = 0; counter < nr_counters; counter++) {
 594                 if (attrs[counter].sample_period)
 595                         continue;
 596
 597                 attrs[counter].sample_period = default_interval;
 598         }
 599
 600         return __cmd_record(argc, argv);
 601 }