tools/perf/builtin-stat.c

   1 /*
   2  * builtin-stat.c
   3  *
   4  * Builtin stat command: Give a precise performance counters summary
   5  * overview about any workload, CPU or specific PID.
   6  *
   7  * Sample output:
   8
   9    $ perf stat ~/hackbench 10
  10    Time: 0.104
  11
  12     Performance counter stats for '/home/mingo/hackbench':
  13
  14        1255.538611  task clock ticks     #      10.143 CPU utilization factor
  15              54011  context switches     #       0.043 M/sec
  16                385  CPU migrations       #       0.000 M/sec
  17              17755  pagefaults           #       0.014 M/sec
  18         3808323185  CPU cycles           #    3033.219 M/sec
  19         1575111190  instructions         #    1254.530 M/sec
  20           17367895  cache references     #      13.833 M/sec
  21            7674421  cache misses         #       6.112 M/sec
  22
  23     Wall-clock time elapsed:   123.786620 msecs
  24
  25  *
  26  * Copyright (C) 2008, Red Hat Inc, Ingo Molnar <mingo@redhat.com>
  27  *
  28  * Improvements and fixes by:
  29  *
  30  *   Arjan van de Ven <arjan@linux.intel.com>
  31  *   Yanmin Zhang <yanmin.zhang@intel.com>
  32  *   Wu Fengguang <fengguang.wu@intel.com>
  33  *   Mike Galbraith <efault@gmx.de>
  34  *   Paul Mackerras <paulus@samba.org>
  35  *   Jaswinder Singh Rajput <jaswinder@kernel.org>
  36  *
  37  * Released under the GPL v2. (and only v2, not any later version)
  38  */
  39
  40 #include "perf.h"
  41 #include "builtin.h"
  42 #include "util/util.h"
  43 #include "util/parse-options.h"
  44 #include "util/parse-events.h"
  45 #include "util/event.h"
  46 #include "util/debug.h"
  47 #include "util/header.h"
  48 #include "util/cpumap.h"
  49 #include "util/thread.h"
  50
  51 #include <sys/prctl.h>
  52 #include <math.h>
  53 #include <locale.h>
  54
  55 static struct perf_event_attr default_attrs[] = {
  56
  57   { .type = PERF_TYPE_SOFTWARE, .config = PERF_COUNT_SW_TASK_CLOCK              },
  58   { .type = PERF_TYPE_SOFTWARE, .config = PERF_COUNT_SW_CONTEXT_SWITCHES        },
  59   { .type = PERF_TYPE_SOFTWARE, .config = PERF_COUNT_SW_CPU_MIGRATIONS          },
  60   { .type = PERF_TYPE_SOFTWARE, .config = PERF_COUNT_SW_PAGE_FAULTS             },
  61
  62   { .type = PERF_TYPE_HARDWARE, .config = PERF_COUNT_HW_CPU_CYCLES              },
  63   { .type = PERF_TYPE_HARDWARE, .config = PERF_COUNT_HW_INSTRUCTIONS            },
  64   { .type = PERF_TYPE_HARDWARE, .config = PERF_COUNT_HW_BRANCH_INSTRUCTIONS     },
  65   { .type = PERF_TYPE_HARDWARE, .config = PERF_COUNT_HW_BRANCH_MISSES           },
  66   { .type = PERF_TYPE_HARDWARE, .config = PERF_COUNT_HW_CACHE_REFERENCES        },
  67   { .type = PERF_TYPE_HARDWARE, .config = PERF_COUNT_HW_CACHE_MISSES            },
  68
  69 };
  70
  71 static bool                     system_wide                     =  false;
  72 static int                      nr_cpus                         =  0;
  73 static int                      run_idx                         =  0;
  74
  75 static int                      run_count                       =  1;
  76 static bool                     no_inherit                      = false;
  77 static bool                     scale                           =  true;
  78 static pid_t                    target_pid                      = -1;
  79 static pid_t                    target_tid                      = -1;
  80 static pid_t                    *all_tids                       =  NULL;
  81 static int                      thread_num                      =  0;
  82 static pid_t                    child_pid                       = -1;
  83 static bool                     null_run                        =  false;
  84 static bool                     big_num                         =  false;
  85 static const char               *cpu_list;
  86
  87
  88 static int                      *fd[MAX_NR_CPUS][MAX_COUNTERS];
  89
  90 static int                      event_scaled[MAX_COUNTERS];
  91
  92 static volatile int done = 0;
  93
  94 struct stats
  95 {
  96         double n, mean, M2;
  97 };
  98
  99 static void update_stats(struct stats *stats, u64 val)
 100 {
 101         double delta;
 102
 103         stats->n++;
 104         delta = val - stats->mean;
 105         stats->mean += delta / stats->n;
 106         stats->M2 += delta*(val - stats->mean);
 107 }
 108
 109 static double avg_stats(struct stats *stats)
 110 {
 111         return stats->mean;
 112 }
 113
 114 /*
 115  * http://en.wikipedia.org/wiki/Algorithms_for_calculating_variance
 116  *
 117  *       (\Sum n_i^2) - ((\Sum n_i)^2)/n
 118  * s^2 = -------------------------------
 119  *                  n - 1
 120  *
 121  * http://en.wikipedia.org/wiki/Stddev
 122  *
 123  * The std dev of the mean is related to the std dev by:
 124  *
 125  *             s
 126  * s_mean = -------
 127  *          sqrt(n)
 128  *
 129  */
 130 static double stddev_stats(struct stats *stats)
 131 {
 132         double variance = stats->M2 / (stats->n - 1);
 133         double variance_mean = variance / stats->n;
 134
 135         return sqrt(variance_mean);
 136 }
 137
 138 struct stats                    event_res_stats[MAX_COUNTERS][3];
 139 struct stats                    runtime_nsecs_stats;
 140 struct stats                    walltime_nsecs_stats;
 141 struct stats                    runtime_cycles_stats;
 142 struct stats                    runtime_branches_stats;
 143
 144 #define MATCH_EVENT(t, c, counter)                      \
 145         (attrs[counter].type == PERF_TYPE_##t &&        \
 146          attrs[counter].config == PERF_COUNT_##c)
 147
 148 #define ERR_PERF_OPEN \
 149 "Error: counter %d, sys_perf_event_open() syscall returned with %d (%s)\n"
 150
 151 static int create_perf_stat_counter(int counter)
 152 {
 153         struct perf_event_attr *attr = attrs + counter;
 154         int thread;
 155         int ncreated = 0;
 156
 157         if (scale)
 158                 attr->read_format = PERF_FORMAT_TOTAL_TIME_ENABLED |
 159                                     PERF_FORMAT_TOTAL_TIME_RUNNING;
 160
 161         if (system_wide) {
 162                 int cpu;
 163
 164                 for (cpu = 0; cpu < nr_cpus; cpu++) {
 165                         fd[cpu][counter][0] = sys_perf_event_open(attr,
 166                                         -1, cpumap[cpu], -1, 0);
 167                         if (fd[cpu][counter][0] < 0)
 168                                 pr_debug(ERR_PERF_OPEN, counter,
 169                                          fd[cpu][counter][0], strerror(errno));
 170                         else
 171                                 ++ncreated;
 172                 }
 173         } else {
 174                 attr->inherit = !no_inherit;
 175                 if (target_pid == -1 && target_tid == -1) {
 176                         attr->disabled = 1;
 177                         attr->enable_on_exec = 1;
 178                 }
 179                 for (thread = 0; thread < thread_num; thread++) {
 180                         fd[0][counter][thread] = sys_perf_event_open(attr,
 181                                 all_tids[thread], -1, -1, 0);
 182                         if (fd[0][counter][thread] < 0)
 183                                 pr_debug(ERR_PERF_OPEN, counter,
 184                                          fd[0][counter][thread],
 185                                          strerror(errno));
 186                         else
 187                                 ++ncreated;
 188                 }
 189         }
 190
 191         return ncreated;
 192 }
 193
 194 /*
 195  * Does the counter have nsecs as a unit?
 196  */
 197 static inline int nsec_counter(int counter)
 198 {
 199         if (MATCH_EVENT(SOFTWARE, SW_CPU_CLOCK, counter) ||
 200             MATCH_EVENT(SOFTWARE, SW_TASK_CLOCK, counter))
 201                 return 1;
 202
 203         return 0;
 204 }
 205
 206 /*
 207  * Read out the results of a single counter:
 208  */
 209 static void read_counter(int counter)
 210 {
 211         u64 count[3], single_count[3];
 212         int cpu;
 213         size_t res, nv;
 214         int scaled;
 215         int i, thread;
 216
 217         count[0] = count[1] = count[2] = 0;
 218
 219         nv = scale ? 3 : 1;
 220         for (cpu = 0; cpu < nr_cpus; cpu++) {
 221                 for (thread = 0; thread < thread_num; thread++) {
 222                         if (fd[cpu][counter][thread] < 0)
 223                                 continue;
 224
 225                         res = read(fd[cpu][counter][thread],
 226                                         single_count, nv * sizeof(u64));
 227                         assert(res == nv * sizeof(u64));
 228
 229                         close(fd[cpu][counter][thread]);
 230                         fd[cpu][counter][thread] = -1;
 231
 232                         count[0] += single_count[0];
 233                         if (scale) {
 234                                 count[1] += single_count[1];
 235                                 count[2] += single_count[2];
 236                         }
 237                 }
 238         }
 239
 240         scaled = 0;
 241         if (scale) {
 242                 if (count[2] == 0) {
 243                         event_scaled[counter] = -1;
 244                         count[0] = 0;
 245                         return;
 246                 }
 247
 248                 if (count[2] < count[1]) {
 249                         event_scaled[counter] = 1;
 250                         count[0] = (unsigned long long)
 251                                 ((double)count[0] * count[1] / count[2] + 0.5);
 252                 }
 253         }
 254
 255         for (i = 0; i < 3; i++)
 256                 update_stats(&event_res_stats[counter][i], count[i]);
 257
 258         if (verbose) {
 259                 fprintf(stderr, "%s: %Ld %Ld %Ld\n", event_name(counter),
 260                                 count[0], count[1], count[2]);
 261         }
 262
 263         /*
 264          * Save the full runtime - to allow normalization during printout:
 265          */
 266         if (MATCH_EVENT(SOFTWARE, SW_TASK_CLOCK, counter))
 267                 update_stats(&runtime_nsecs_stats, count[0]);
 268         if (MATCH_EVENT(HARDWARE, HW_CPU_CYCLES, counter))
 269                 update_stats(&runtime_cycles_stats, count[0]);
 270         if (MATCH_EVENT(HARDWARE, HW_BRANCH_INSTRUCTIONS, counter))
 271                 update_stats(&runtime_branches_stats, count[0]);
 272 }
 273
 274 static int run_perf_stat(int argc __used, const char **argv)
 275 {
 276         unsigned long long t0, t1;
 277         int status = 0;
 278         int counter, ncreated = 0;
 279         int child_ready_pipe[2], go_pipe[2];
 280         const bool forks = (argc > 0);
 281         char buf;
 282
 283         if (!system_wide)
 284                 nr_cpus = 1;
 285
 286         if (forks && (pipe(child_ready_pipe) < 0 || pipe(go_pipe) < 0)) {
 287                 perror("failed to create pipes");
 288                 exit(1);
 289         }
 290
 291         if (forks) {
 292                 if ((child_pid = fork()) < 0)
 293                         perror("failed to fork");
 294
 295                 if (!child_pid) {
 296                         close(child_ready_pipe[0]);
 297                         close(go_pipe[1]);
 298                         fcntl(go_pipe[0], F_SETFD, FD_CLOEXEC);
 299
 300                         /*
 301                          * Do a dummy execvp to get the PLT entry resolved,
 302                          * so we avoid the resolver overhead on the real
 303                          * execvp call.
 304                          */
 305                         execvp("", (char **)argv);
 306
 307                         /*
 308                          * Tell the parent we're ready to go
 309                          */
 310                         close(child_ready_pipe[1]);
 311
 312                         /*
 313                          * Wait until the parent tells us to go.
 314                          */
 315                         if (read(go_pipe[0], &buf, 1) == -1)
 316                                 perror("unable to read pipe");
 317
 318                         execvp(argv[0], (char **)argv);
 319
 320                         perror(argv[0]);
 321                         exit(-1);
 322                 }
 323
 324                 if (target_tid == -1 && target_pid == -1 && !system_wide)
 325                         all_tids[0] = child_pid;
 326
 327                 /*
 328                  * Wait for the child to be ready to exec.
 329                  */
 330                 close(child_ready_pipe[1]);
 331                 close(go_pipe[0]);
 332                 if (read(child_ready_pipe[0], &buf, 1) == -1)
 333                         perror("unable to read pipe");
 334                 close(child_ready_pipe[0]);
 335         }
 336
 337         for (counter = 0; counter < nr_counters; counter++)
 338                 ncreated += create_perf_stat_counter(counter);
 339
 340         if (ncreated == 0) {
 341                 pr_err("No permission to collect %sstats.\n"
 342                        "Consider tweaking /proc/sys/kernel/perf_event_paranoid.\n",
 343                        system_wide ? "system-wide " : "");
 344                 if (child_pid != -1)
 345                         kill(child_pid, SIGTERM);
 346                 return -1;
 347         }
 348
 349         /*
 350          * Enable counters and exec the command:
 351          */
 352         t0 = rdclock();
 353
 354         if (forks) {
 355                 close(go_pipe[1]);
 356                 wait(&status);
 357         } else {
 358                 while(!done) sleep(1);
 359         }
 360
 361         t1 = rdclock();
 362
 363         update_stats(&walltime_nsecs_stats, t1 - t0);
 364
 365         for (counter = 0; counter < nr_counters; counter++)
 366                 read_counter(counter);
 367
 368         return WEXITSTATUS(status);
 369 }
 370
 371 static void print_noise(int counter, double avg)
 372 {
 373         if (run_count == 1)
 374                 return;
 375
 376         fprintf(stderr, "   ( +- %7.3f%% )",
 377                         100 * stddev_stats(&event_res_stats[counter][0]) / avg);
 378 }
 379
 380 static void nsec_printout(int counter, double avg)
 381 {
 382         double msecs = avg / 1e6;
 383
 384         fprintf(stderr, " %18.6f  %-24s", msecs, event_name(counter));
 385
 386         if (MATCH_EVENT(SOFTWARE, SW_TASK_CLOCK, counter)) {
 387                 fprintf(stderr, " # %10.3f CPUs ",
 388                                 avg / avg_stats(&walltime_nsecs_stats));
 389         }
 390 }
 391
 392 static void abs_printout(int counter, double avg)
 393 {
 394         double total, ratio = 0.0;
 395
 396         if (big_num)
 397                 fprintf(stderr, " %'18.0f  %-24s", avg, event_name(counter));
 398         else
 399                 fprintf(stderr, " %18.0f  %-24s", avg, event_name(counter));
 400
 401         if (MATCH_EVENT(HARDWARE, HW_INSTRUCTIONS, counter)) {
 402                 total = avg_stats(&runtime_cycles_stats);
 403
 404                 if (total)
 405                         ratio = avg / total;
 406
 407                 fprintf(stderr, " # %10.3f IPC  ", ratio);
 408         } else if (MATCH_EVENT(HARDWARE, HW_BRANCH_MISSES, counter) &&
 409                         runtime_branches_stats.n != 0) {
 410                 total = avg_stats(&runtime_branches_stats);
 411
 412                 if (total)
 413                         ratio = avg * 100 / total;
 414
 415                 fprintf(stderr, " # %10.3f %%    ", ratio);
 416
 417         } else if (runtime_nsecs_stats.n != 0) {
 418                 total = avg_stats(&runtime_nsecs_stats);
 419
 420                 if (total)
 421                         ratio = 1000.0 * avg / total;
 422
 423                 fprintf(stderr, " # %10.3f M/sec", ratio);
 424         }
 425 }
 426
 427 /*
 428  * Print out the results of a single counter:
 429  */
 430 static void print_counter(int counter)
 431 {
 432         double avg = avg_stats(&event_res_stats[counter][0]);
 433         int scaled = event_scaled[counter];
 434
 435         if (scaled == -1) {
 436                 fprintf(stderr, " %18s  %-24s\n",
 437                         "<not counted>", event_name(counter));
 438                 return;
 439         }
 440
 441         if (nsec_counter(counter))
 442                 nsec_printout(counter, avg);
 443         else
 444                 abs_printout(counter, avg);
 445
 446         print_noise(counter, avg);
 447
 448         if (scaled) {
 449                 double avg_enabled, avg_running;
 450
 451                 avg_enabled = avg_stats(&event_res_stats[counter][1]);
 452                 avg_running = avg_stats(&event_res_stats[counter][2]);
 453
 454                 fprintf(stderr, "  (scaled from %.2f%%)",
 455                                 100 * avg_running / avg_enabled);
 456         }
 457
 458         fprintf(stderr, "\n");
 459 }
 460
 461 static void print_stat(int argc, const char **argv)
 462 {
 463         int i, counter;
 464
 465         fflush(stdout);
 466
 467         fprintf(stderr, "\n");
 468         fprintf(stderr, " Performance counter stats for ");
 469         if(target_pid == -1 && target_tid == -1) {
 470                 fprintf(stderr, "\'%s", argv[0]);
 471                 for (i = 1; i < argc; i++)
 472                         fprintf(stderr, " %s", argv[i]);
 473         } else if (target_pid != -1)
 474                 fprintf(stderr, "process id \'%d", target_pid);
 475         else
 476                 fprintf(stderr, "thread id \'%d", target_tid);
 477
 478         fprintf(stderr, "\'");
 479         if (run_count > 1)
 480                 fprintf(stderr, " (%d runs)", run_count);
 481         fprintf(stderr, ":\n\n");
 482
 483         for (counter = 0; counter < nr_counters; counter++)
 484                 print_counter(counter);
 485
 486         fprintf(stderr, "\n");
 487         fprintf(stderr, " %18.9f  seconds time elapsed",
 488                         avg_stats(&walltime_nsecs_stats)/1e9);
 489         if (run_count > 1) {
 490                 fprintf(stderr, "   ( +- %7.3f%% )",
 491                                 100*stddev_stats(&walltime_nsecs_stats) /
 492                                 avg_stats(&walltime_nsecs_stats));
 493         }
 494         fprintf(stderr, "\n\n");
 495 }
 496
 497 static volatile int signr = -1;
 498
 499 static void skip_signal(int signo)
 500 {
 501         if(child_pid == -1)
 502                 done = 1;
 503
 504         signr = signo;
 505 }
 506
 507 static void sig_atexit(void)
 508 {
 509         if (child_pid != -1)
 510                 kill(child_pid, SIGTERM);
 511
 512         if (signr == -1)
 513                 return;
 514
 515         signal(signr, SIG_DFL);
 516         kill(getpid(), signr);
 517 }
 518
 519 static const char * const stat_usage[] = {
 520         "perf stat [<options>] [<command>]",
 521         NULL
 522 };
 523
 524 static const struct option options[] = {
 525         OPT_CALLBACK('e', "event", NULL, "event",
 526                      "event selector. use 'perf list' to list available events",
 527                      parse_events),
 528         OPT_BOOLEAN('i', "no-inherit", &no_inherit,
 529                     "child tasks do not inherit counters"),
 530         OPT_INTEGER('p', "pid", &target_pid,
 531                     "stat events on existing process id"),
 532         OPT_INTEGER('t', "tid", &target_tid,
 533                     "stat events on existing thread id"),
 534         OPT_BOOLEAN('a', "all-cpus", &system_wide,
 535                     "system-wide collection from all CPUs"),
 536         OPT_BOOLEAN('c', "scale", &scale,
 537                     "scale/normalize counters"),
 538         OPT_INCR('v', "verbose", &verbose,
 539                     "be more verbose (show counter open errors, etc)"),
 540         OPT_INTEGER('r', "repeat", &run_count,
 541                     "repeat command and print average + stddev (max: 100)"),
 542         OPT_BOOLEAN('n', "null", &null_run,
 543                     "null run - dont start any counters"),
 544         OPT_BOOLEAN('B', "big-num", &big_num,
 545                     "print large numbers with thousands\' separators"),
 546         OPT_STRING('C', "cpu", &cpu_list, "cpu",
 547                     "list of cpus to monitor in system-wide"),
 548         OPT_END()
 549 };
 550
 551 int cmd_stat(int argc, const char **argv, const char *prefix __used)
 552 {
 553         int status;
 554         int i,j;
 555
 556         setlocale(LC_ALL, "");
 557
 558         argc = parse_options(argc, argv, options, stat_usage,
 559                 PARSE_OPT_STOP_AT_NON_OPTION);
 560         if (!argc && target_pid == -1 && target_tid == -1)
 561                 usage_with_options(stat_usage, options);
 562         if (run_count <= 0)
 563                 usage_with_options(stat_usage, options);
 564
 565         /* Set attrs and nr_counters if no event is selected and !null_run */
 566         if (!null_run && !nr_counters) {
 567                 memcpy(attrs, default_attrs, sizeof(default_attrs));
 568                 nr_counters = ARRAY_SIZE(default_attrs);
 569         }
 570
 571         if (system_wide)
 572                 nr_cpus = read_cpu_map(cpu_list);
 573         else
 574                 nr_cpus = 1;
 575
 576         if (nr_cpus < 1)
 577                 usage_with_options(stat_usage, options);
 578
 579         if (target_pid != -1) {
 580                 target_tid = target_pid;
 581                 thread_num = find_all_tid(target_pid, &all_tids);
 582                 if (thread_num <= 0) {
 583                         fprintf(stderr, "Can't find all threads of pid %d\n",
 584                                         target_pid);
 585                         usage_with_options(stat_usage, options);
 586                 }
 587         } else {
 588                 all_tids=malloc(sizeof(pid_t));
 589                 if (!all_tids)
 590                         return -ENOMEM;
 591
 592                 all_tids[0] = target_tid;
 593                 thread_num = 1;
 594         }
 595
 596         for (i = 0; i < MAX_NR_CPUS; i++) {
 597                 for (j = 0; j < MAX_COUNTERS; j++) {
 598                         fd[i][j] = malloc(sizeof(int)*thread_num);
 599                         if (!fd[i][j])
 600                                 return -ENOMEM;
 601                 }
 602         }
 603
 604         /*
 605          * We dont want to block the signals - that would cause
 606          * child tasks to inherit that and Ctrl-C would not work.
 607          * What we want is for Ctrl-C to work in the exec()-ed
 608          * task, but being ignored by perf stat itself:
 609          */
 610         atexit(sig_atexit);
 611         signal(SIGINT,  skip_signal);
 612         signal(SIGALRM, skip_signal);
 613         signal(SIGABRT, skip_signal);
 614
 615         status = 0;
 616         for (run_idx = 0; run_idx < run_count; run_idx++) {
 617                 if (run_count != 1 && verbose)
 618                         fprintf(stderr, "[ perf stat: executing run #%d ... ]\n", run_idx + 1);
 619                 status = run_perf_stat(argc, argv);
 620         }
 621
 622         if (status != -1)
 623                 print_stat(argc, argv);
 624
 625         return status;
 626 }