tools/perf/builtin-top.c

   1 /*
   2  * builtin-top.c
   3  *
   4  * Builtin top command: Display a continuously updated profile of
   5  * any workload, CPU or specific PID.
   6  *
   7  * Copyright (C) 2008, Red Hat Inc, Ingo Molnar <mingo@redhat.com>
   8  *
   9  * Improvements and fixes by:
  10  *
  11  *   Arjan van de Ven <arjan@linux.intel.com>
  12  *   Yanmin Zhang <yanmin.zhang@intel.com>
  13  *   Wu Fengguang <fengguang.wu@intel.com>
  14  *   Mike Galbraith <efault@gmx.de>
  15  *   Paul Mackerras <paulus@samba.org>
  16  *
  17  * Released under the GPL v2. (and only v2, not any later version)
  18  */
  19 #include "builtin.h"
  20
  21 #include "perf.h"
  22
  23 #include "util/symbol.h"
  24 #include "util/color.h"
  25 #include "util/util.h"
  26 #include "util/rbtree.h"
  27 #include "util/parse-options.h"
  28 #include "util/parse-events.h"
  29
  30 #include <assert.h>
  31 #include <fcntl.h>
  32
  33 #include <stdio.h>
  34
  35 #include <errno.h>
  36 #include <time.h>
  37 #include <sched.h>
  38 #include <pthread.h>
  39
  40 #include <sys/syscall.h>
  41 #include <sys/ioctl.h>
  42 #include <sys/poll.h>
  43 #include <sys/prctl.h>
  44 #include <sys/wait.h>
  45 #include <sys/uio.h>
  46 #include <sys/mman.h>
  47
  48 #include <linux/unistd.h>
  49 #include <linux/types.h>
  50
  51 static int                      fd[MAX_NR_CPUS][MAX_COUNTERS];
  52
  53 static int                      system_wide                     =  0;
  54
  55 static int                      default_interval                = 100000;
  56
  57 static __u64                    count_filter                    =  5;
  58 static int                      print_entries                   = 15;
  59
  60 static int                      target_pid                      = -1;
  61 static int                      profile_cpu                     = -1;
  62 static int                      nr_cpus                         =  0;
  63 static unsigned int             realtime_prio                   =  0;
  64 static int                      group                           =  0;
  65 static unsigned int             page_size;
  66 static unsigned int             mmap_pages                      = 16;
  67 static int                      freq                            =  0;
  68 static int                      verbose                         =  0;
  69
  70 static char                     *sym_filter;
  71 static unsigned long            filter_start;
  72 static unsigned long            filter_end;
  73
  74 static int                      delay_secs                      =  2;
  75 static int                      zero;
  76 static int                      dump_symtab;
  77
  78 /*
  79  * Symbols
  80  */
  81
  82 static uint64_t                 min_ip;
  83 static uint64_t                 max_ip = -1ll;
  84
  85 struct sym_entry {
  86         struct rb_node          rb_node;
  87         struct list_head        node;
  88         unsigned long           count[MAX_COUNTERS];
  89         unsigned long           snap_count;
  90         double                  weight;
  91         int                     skip;
  92 };
  93
  94 struct sym_entry                *sym_filter_entry;
  95
  96 struct dso                      *kernel_dso;
  97
  98 /*
  99  * Symbols will be added here in record_ip and will get out
 100  * after decayed.
 101  */
 102 static LIST_HEAD(active_symbols);
 103 static pthread_mutex_t active_symbols_lock = PTHREAD_MUTEX_INITIALIZER;
 104
 105 /*
 106  * Ordering weight: count-1 * count-2 * ... / count-n
 107  */
 108 static double sym_weight(const struct sym_entry *sym)
 109 {
 110         double weight = sym->snap_count;
 111         int counter;
 112
 113         for (counter = 1; counter < nr_counters-1; counter++)
 114                 weight *= sym->count[counter];
 115
 116         weight /= (sym->count[counter] + 1);
 117
 118         return weight;
 119 }
 120
 121 static long                     samples;
 122 static long                     userspace_samples;
 123 static const char               CONSOLE_CLEAR[] = "\e[H\e[2J";
 124
 125 static void __list_insert_active_sym(struct sym_entry *syme)
 126 {
 127         list_add(&syme->node, &active_symbols);
 128 }
 129
 130 static void list_remove_active_sym(struct sym_entry *syme)
 131 {
 132         pthread_mutex_lock(&active_symbols_lock);
 133         list_del_init(&syme->node);
 134         pthread_mutex_unlock(&active_symbols_lock);
 135 }
 136
 137 static void rb_insert_active_sym(struct rb_root *tree, struct sym_entry *se)
 138 {
 139         struct rb_node **p = &tree->rb_node;
 140         struct rb_node *parent = NULL;
 141         struct sym_entry *iter;
 142
 143         while (*p != NULL) {
 144                 parent = *p;
 145                 iter = rb_entry(parent, struct sym_entry, rb_node);
 146
 147                 if (se->weight > iter->weight)
 148                         p = &(*p)->rb_left;
 149                 else
 150                         p = &(*p)->rb_right;
 151         }
 152
 153         rb_link_node(&se->rb_node, parent, p);
 154         rb_insert_color(&se->rb_node, tree);
 155 }
 156
 157 static void print_sym_table(void)
 158 {
 159         int printed = 0, j;
 160         int counter;
 161         float samples_per_sec = samples/delay_secs;
 162         float ksamples_per_sec = (samples-userspace_samples)/delay_secs;
 163         float sum_ksamples = 0.0;
 164         struct sym_entry *syme, *n;
 165         struct rb_root tmp = RB_ROOT;
 166         struct rb_node *nd;
 167
 168         samples = userspace_samples = 0;
 169
 170         /* Sort the active symbols */
 171         pthread_mutex_lock(&active_symbols_lock);
 172         syme = list_entry(active_symbols.next, struct sym_entry, node);
 173         pthread_mutex_unlock(&active_symbols_lock);
 174
 175         list_for_each_entry_safe_from(syme, n, &active_symbols, node) {
 176                 syme->snap_count = syme->count[0];
 177                 if (syme->snap_count != 0) {
 178                         syme->weight = sym_weight(syme);
 179                         rb_insert_active_sym(&tmp, syme);
 180                         sum_ksamples += syme->snap_count;
 181
 182                         for (j = 0; j < nr_counters; j++)
 183                                 syme->count[j] = zero ? 0 : syme->count[j] * 7 / 8;
 184                 } else
 185                         list_remove_active_sym(syme);
 186         }
 187
 188         puts(CONSOLE_CLEAR);
 189
 190         printf(
 191 "------------------------------------------------------------------------------\n");
 192         printf( "   PerfTop:%8.0f irqs/sec  kernel:%4.1f%% [",
 193                 samples_per_sec,
 194                 100.0 - (100.0*((samples_per_sec-ksamples_per_sec)/samples_per_sec)));
 195
 196         if (nr_counters == 1) {
 197                 printf("%Ld", attrs[0].sample_period);
 198                 if (freq)
 199                         printf("Hz ");
 200                 else
 201                         printf(" ");
 202         }
 203
 204         for (counter = 0; counter < nr_counters; counter++) {
 205                 if (counter)
 206                         printf("/");
 207
 208                 printf("%s", event_name(counter));
 209         }
 210
 211         printf( "], ");
 212
 213         if (target_pid != -1)
 214                 printf(" (target_pid: %d", target_pid);
 215         else
 216                 printf(" (all");
 217
 218         if (profile_cpu != -1)
 219                 printf(", cpu: %d)\n", profile_cpu);
 220         else {
 221                 if (target_pid != -1)
 222                         printf(")\n");
 223                 else
 224                         printf(", %d CPUs)\n", nr_cpus);
 225         }
 226
 227         printf("------------------------------------------------------------------------------\n\n");
 228
 229         if (nr_counters == 1)
 230                 printf("             samples    pcnt");
 231         else
 232                 printf("  weight     samples    pcnt");
 233
 234         printf("         RIP          kernel function\n"
 235                        "  ______     _______   _____   ________________   _______________\n\n"
 236         );
 237
 238         for (nd = rb_first(&tmp); nd; nd = rb_next(nd)) {
 239                 struct sym_entry *syme = rb_entry(nd, struct sym_entry, rb_node);
 240                 struct symbol *sym = (struct symbol *)(syme + 1);
 241                 char *color = PERF_COLOR_NORMAL;
 242                 double pcnt;
 243
 244                 if (++printed > print_entries || syme->snap_count < count_filter)
 245                         continue;
 246
 247                 pcnt = 100.0 - (100.0 * ((sum_ksamples - syme->snap_count) /
 248                                          sum_ksamples));
 249
 250                 /*
 251                  * We color high-overhead entries in red, low-overhead
 252                  * entries in green - and keep the middle ground normal:
 253                  */
 254                 if (pcnt >= 5.0)
 255                         color = PERF_COLOR_RED;
 256                 if (pcnt < 0.5)
 257                         color = PERF_COLOR_GREEN;
 258
 259                 if (nr_counters == 1)
 260                         printf("%20.2f - ", syme->weight);
 261                 else
 262                         printf("%9.1f %10ld - ", syme->weight, syme->snap_count);
 263
 264                 color_fprintf(stdout, color, "%4.1f%%", pcnt);
 265                 printf(" - %016llx : %s\n", sym->start, sym->name);
 266         }
 267 }
 268
 269 static void *display_thread(void *arg)
 270 {
 271         struct pollfd stdin_poll = { .fd = 0, .events = POLLIN };
 272         int delay_msecs = delay_secs * 1000;
 273
 274         printf("PerfTop refresh period: %d seconds\n", delay_secs);
 275
 276         do {
 277                 print_sym_table();
 278         } while (!poll(&stdin_poll, 1, delay_msecs) == 1);
 279
 280         printf("key pressed - exiting.\n");
 281         exit(0);
 282
 283         return NULL;
 284 }
 285
 286 static int symbol_filter(struct dso *self, struct symbol *sym)
 287 {
 288         static int filter_match;
 289         struct sym_entry *syme;
 290         const char *name = sym->name;
 291
 292         if (!strcmp(name, "_text") ||
 293             !strcmp(name, "_etext") ||
 294             !strcmp(name, "_sinittext") ||
 295             !strncmp("init_module", name, 11) ||
 296             !strncmp("cleanup_module", name, 14) ||
 297             strstr(name, "_text_start") ||
 298             strstr(name, "_text_end"))
 299                 return 1;
 300
 301         syme = dso__sym_priv(self, sym);
 302         /* Tag samples to be skipped. */
 303         if (!strcmp("default_idle", name) ||
 304             !strcmp("cpu_idle", name) ||
 305             !strcmp("enter_idle", name) ||
 306             !strcmp("exit_idle", name) ||
 307             !strcmp("mwait_idle", name))
 308                 syme->skip = 1;
 309
 310         if (filter_match == 1) {
 311                 filter_end = sym->start;
 312                 filter_match = -1;
 313                 if (filter_end - filter_start > 10000) {
 314                         fprintf(stderr,
 315                                 "hm, too large filter symbol <%s> - skipping.\n",
 316                                 sym_filter);
 317                         fprintf(stderr, "symbol filter start: %016lx\n",
 318                                 filter_start);
 319                         fprintf(stderr, "                end: %016lx\n",
 320                                 filter_end);
 321                         filter_end = filter_start = 0;
 322                         sym_filter = NULL;
 323                         sleep(1);
 324                 }
 325         }
 326
 327         if (filter_match == 0 && sym_filter && !strcmp(name, sym_filter)) {
 328                 filter_match = 1;
 329                 filter_start = sym->start;
 330         }
 331
 332
 333         return 0;
 334 }
 335
 336 static int parse_symbols(void)
 337 {
 338         struct rb_node *node;
 339         struct symbol  *sym;
 340
 341         kernel_dso = dso__new("[kernel]", sizeof(struct sym_entry));
 342         if (kernel_dso == NULL)
 343                 return -1;
 344
 345         if (dso__load_kernel(kernel_dso, NULL, symbol_filter, 1) != 0)
 346                 goto out_delete_dso;
 347
 348         node = rb_first(&kernel_dso->syms);
 349         sym = rb_entry(node, struct symbol, rb_node);
 350         min_ip = sym->start;
 351
 352         node = rb_last(&kernel_dso->syms);
 353         sym = rb_entry(node, struct symbol, rb_node);
 354         max_ip = sym->end;
 355
 356         if (dump_symtab)
 357                 dso__fprintf(kernel_dso, stderr);
 358
 359         return 0;
 360
 361 out_delete_dso:
 362         dso__delete(kernel_dso);
 363         kernel_dso = NULL;
 364         return -1;
 365 }
 366
 367 #define TRACE_COUNT     3
 368
 369 /*
 370  * Binary search in the histogram table and record the hit:
 371  */
 372 static void record_ip(uint64_t ip, int counter)
 373 {
 374         struct symbol *sym = dso__find_symbol(kernel_dso, ip);
 375
 376         if (sym != NULL) {
 377                 struct sym_entry *syme = dso__sym_priv(kernel_dso, sym);
 378
 379                 if (!syme->skip) {
 380                         syme->count[counter]++;
 381                         pthread_mutex_lock(&active_symbols_lock);
 382                         if (list_empty(&syme->node) || !syme->node.next)
 383                                 __list_insert_active_sym(syme);
 384                         pthread_mutex_unlock(&active_symbols_lock);
 385                         return;
 386                 }
 387         }
 388
 389         samples--;
 390 }
 391
 392 static void process_event(uint64_t ip, int counter)
 393 {
 394         samples++;
 395
 396         if (ip < min_ip || ip > max_ip) {
 397                 userspace_samples++;
 398                 return;
 399         }
 400
 401         record_ip(ip, counter);
 402 }
 403
 404 struct mmap_data {
 405         int                     counter;
 406         void                    *base;
 407         unsigned int            mask;
 408         unsigned int            prev;
 409 };
 410
 411 static unsigned int mmap_read_head(struct mmap_data *md)
 412 {
 413         struct perf_counter_mmap_page *pc = md->base;
 414         int head;
 415
 416         head = pc->data_head;
 417         rmb();
 418
 419         return head;
 420 }
 421
 422 struct timeval last_read, this_read;
 423
 424 static void mmap_read_counter(struct mmap_data *md)
 425 {
 426         unsigned int head = mmap_read_head(md);
 427         unsigned int old = md->prev;
 428         unsigned char *data = md->base + page_size;
 429         int diff;
 430
 431         gettimeofday(&this_read, NULL);
 432
 433         /*
 434          * If we're further behind than half the buffer, there's a chance
 435          * the writer will bite our tail and mess up the samples under us.
 436          *
 437          * If we somehow ended up ahead of the head, we got messed up.
 438          *
 439          * In either case, truncate and restart at head.
 440          */
 441         diff = head - old;
 442         if (diff > md->mask / 2 || diff < 0) {
 443                 struct timeval iv;
 444                 unsigned long msecs;
 445
 446                 timersub(&this_read, &last_read, &iv);
 447                 msecs = iv.tv_sec*1000 + iv.tv_usec/1000;
 448
 449                 fprintf(stderr, "WARNING: failed to keep up with mmap data."
 450                                 "  Last read %lu msecs ago.\n", msecs);
 451
 452                 /*
 453                  * head points to a known good entry, start there.
 454                  */
 455                 old = head;
 456         }
 457
 458         last_read = this_read;
 459
 460         for (; old != head;) {
 461                 struct ip_event {
 462                         struct perf_event_header header;
 463                         __u64 ip;
 464                         __u32 pid, target_pid;
 465                 };
 466                 struct mmap_event {
 467                         struct perf_event_header header;
 468                         __u32 pid, target_pid;
 469                         __u64 start;
 470                         __u64 len;
 471                         __u64 pgoff;
 472                         char filename[PATH_MAX];
 473                 };
 474
 475                 typedef union event_union {
 476                         struct perf_event_header header;
 477                         struct ip_event ip;
 478                         struct mmap_event mmap;
 479                 } event_t;
 480
 481                 event_t *event = (event_t *)&data[old & md->mask];
 482
 483                 event_t event_copy;
 484
 485                 size_t size = event->header.size;
 486
 487                 /*
 488                  * Event straddles the mmap boundary -- header should always
 489                  * be inside due to u64 alignment of output.
 490                  */
 491                 if ((old & md->mask) + size != ((old + size) & md->mask)) {
 492                         unsigned int offset = old;
 493                         unsigned int len = min(sizeof(*event), size), cpy;
 494                         void *dst = &event_copy;
 495
 496                         do {
 497                                 cpy = min(md->mask + 1 - (offset & md->mask), len);
 498                                 memcpy(dst, &data[offset & md->mask], cpy);
 499                                 offset += cpy;
 500                                 dst += cpy;
 501                                 len -= cpy;
 502                         } while (len);
 503
 504                         event = &event_copy;
 505                 }
 506
 507                 old += size;
 508
 509                 if (event->header.misc & PERF_EVENT_MISC_OVERFLOW) {
 510                         if (event->header.type & PERF_SAMPLE_IP)
 511                                 process_event(event->ip.ip, md->counter);
 512                 }
 513         }
 514
 515         md->prev = old;
 516 }
 517
 518 static struct pollfd event_array[MAX_NR_CPUS * MAX_COUNTERS];
 519 static struct mmap_data mmap_array[MAX_NR_CPUS][MAX_COUNTERS];
 520
 521 static void mmap_read(void)
 522 {
 523         int i, counter;
 524
 525         for (i = 0; i < nr_cpus; i++) {
 526                 for (counter = 0; counter < nr_counters; counter++)
 527                         mmap_read_counter(&mmap_array[i][counter]);
 528         }
 529 }
 530
 531 int nr_poll;
 532 int group_fd;
 533
 534 static void start_counter(int i, int counter)
 535 {
 536         struct perf_counter_attr *attr;
 537         unsigned int cpu;
 538
 539         cpu = profile_cpu;
 540         if (target_pid == -1 && profile_cpu == -1)
 541                 cpu = i;
 542
 543         attr = attrs + counter;
 544
 545         attr->sample_type       = PERF_SAMPLE_IP | PERF_SAMPLE_TID;
 546         attr->freq              = freq;
 547
 548 try_again:
 549         fd[i][counter] = sys_perf_counter_open(attr, target_pid, cpu, group_fd, 0);
 550
 551         if (fd[i][counter] < 0) {
 552                 int err = errno;
 553
 554                 if (err == EPERM)
 555                         die("No permission - are you root?\n");
 556                 /*
 557                  * If it's cycles then fall back to hrtimer
 558                  * based cpu-clock-tick sw counter, which
 559                  * is always available even if no PMU support:
 560                  */
 561                 if (attr->type == PERF_TYPE_HARDWARE
 562                         && attr->config == PERF_COUNT_CPU_CYCLES) {
 563
 564                         if (verbose)
 565                                 warning(" ... trying to fall back to cpu-clock-ticks\n");
 566
 567                         attr->type = PERF_TYPE_SOFTWARE;
 568                         attr->config = PERF_COUNT_CPU_CLOCK;
 569                         goto try_again;
 570                 }
 571                 printf("\n");
 572                 error("perfcounter syscall returned with %d (%s)\n",
 573                         fd[i][counter], strerror(err));
 574                 die("No CONFIG_PERF_COUNTERS=y kernel support configured?\n");
 575                 exit(-1);
 576         }
 577         assert(fd[i][counter] >= 0);
 578         fcntl(fd[i][counter], F_SETFL, O_NONBLOCK);
 579
 580         /*
 581          * First counter acts as the group leader:
 582          */
 583         if (group && group_fd == -1)
 584                 group_fd = fd[i][counter];
 585
 586         event_array[nr_poll].fd = fd[i][counter];
 587         event_array[nr_poll].events = POLLIN;
 588         nr_poll++;
 589
 590         mmap_array[i][counter].counter = counter;
 591         mmap_array[i][counter].prev = 0;
 592         mmap_array[i][counter].mask = mmap_pages*page_size - 1;
 593         mmap_array[i][counter].base = mmap(NULL, (mmap_pages+1)*page_size,
 594                         PROT_READ, MAP_SHARED, fd[i][counter], 0);
 595         if (mmap_array[i][counter].base == MAP_FAILED)
 596                 die("failed to mmap with %d (%s)\n", errno, strerror(errno));
 597 }
 598
 599 static int __cmd_top(void)
 600 {
 601         pthread_t thread;
 602         int i, counter;
 603         int ret;
 604
 605         for (i = 0; i < nr_cpus; i++) {
 606                 group_fd = -1;
 607                 for (counter = 0; counter < nr_counters; counter++)
 608                         start_counter(i, counter);
 609         }
 610
 611         /* Wait for a minimal set of events before starting the snapshot */
 612         poll(event_array, nr_poll, 100);
 613
 614         mmap_read();
 615
 616         if (pthread_create(&thread, NULL, display_thread, NULL)) {
 617                 printf("Could not create display thread.\n");
 618                 exit(-1);
 619         }
 620
 621         if (realtime_prio) {
 622                 struct sched_param param;
 623
 624                 param.sched_priority = realtime_prio;
 625                 if (sched_setscheduler(0, SCHED_FIFO, &param)) {
 626                         printf("Could not set realtime priority.\n");
 627                         exit(-1);
 628                 }
 629         }
 630
 631         while (1) {
 632                 int hits = samples;
 633
 634                 mmap_read();
 635
 636                 if (hits == samples)
 637                         ret = poll(event_array, nr_poll, 100);
 638         }
 639
 640         return 0;
 641 }
 642
 643 static const char * const top_usage[] = {
 644         "perf top [<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('c', "count", &default_interval,
 653                     "event period to sample"),
 654         OPT_INTEGER('p', "pid", &target_pid,
 655                     "profile events on existing pid"),
 656         OPT_BOOLEAN('a', "all-cpus", &system_wide,
 657                             "system-wide collection from all CPUs"),
 658         OPT_INTEGER('C', "CPU", &profile_cpu,
 659                     "CPU to profile on"),
 660         OPT_INTEGER('m', "mmap-pages", &mmap_pages,
 661                     "number of mmap data pages"),
 662         OPT_INTEGER('r', "realtime", &realtime_prio,
 663                     "collect data with this RT SCHED_FIFO priority"),
 664         OPT_INTEGER('d', "delay", &delay_secs,
 665                     "number of seconds to delay between refreshes"),
 666         OPT_BOOLEAN('D', "dump-symtab", &dump_symtab,
 667                             "dump the symbol table used for profiling"),
 668         OPT_INTEGER('f', "count-filter", &count_filter,
 669                     "only display functions with more events than this"),
 670         OPT_BOOLEAN('g', "group", &group,
 671                             "put the counters into a counter group"),
 672         OPT_STRING('s', "sym-filter", &sym_filter, "pattern",
 673                     "only display symbols matchig this pattern"),
 674         OPT_BOOLEAN('z', "zero", &group,
 675                     "zero history across updates"),
 676         OPT_INTEGER('F', "freq", &freq,
 677                     "profile at this frequency"),
 678         OPT_INTEGER('E', "entries", &print_entries,
 679                     "display this many functions"),
 680         OPT_BOOLEAN('v', "verbose", &verbose,
 681                     "be more verbose (show counter open errors, etc)"),
 682         OPT_END()
 683 };
 684
 685 int cmd_top(int argc, const char **argv, const char *prefix)
 686 {
 687         int counter;
 688
 689         page_size = sysconf(_SC_PAGE_SIZE);
 690
 691         argc = parse_options(argc, argv, options, top_usage, 0);
 692         if (argc)
 693                 usage_with_options(top_usage, options);
 694
 695         if (freq) {
 696                 default_interval = freq;
 697                 freq = 1;
 698         }
 699
 700         /* CPU and PID are mutually exclusive */
 701         if (target_pid != -1 && profile_cpu != -1) {
 702                 printf("WARNING: PID switch overriding CPU\n");
 703                 sleep(1);
 704                 profile_cpu = -1;
 705         }
 706
 707         if (!nr_counters)
 708                 nr_counters = 1;
 709
 710         if (delay_secs < 1)
 711                 delay_secs = 1;
 712
 713         parse_symbols();
 714
 715         /*
 716          * Fill in the ones not specifically initialized via -c:
 717          */
 718         for (counter = 0; counter < nr_counters; counter++) {
 719                 if (attrs[counter].sample_period)
 720                         continue;
 721
 722                 attrs[counter].sample_period = default_interval;
 723         }
 724
 725         nr_cpus = sysconf(_SC_NPROCESSORS_ONLN);
 726         assert(nr_cpus <= MAX_NR_CPUS);
 727         assert(nr_cpus >= 0);
 728
 729         if (target_pid != -1 || profile_cpu != -1)
 730                 nr_cpus = 1;
 731
 732         return __cmd_top();
 733 }