Documentation/perf_counter/builtin-top.c

   1 /*
   2  * kerneltop.c: show top kernel functions - performance counters showcase
   3
   4    Build with:
   5
   6      make -C Documentation/perf_counter/
   7
   8    Sample output:
   9
  10 ------------------------------------------------------------------------------
  11  KernelTop:    2669 irqs/sec  [NMI, cache-misses/cache-refs],  (all, cpu: 2)
  12 ------------------------------------------------------------------------------
  13
  14              weight         RIP          kernel function
  15              ______   ________________   _______________
  16
  17               35.20 - ffffffff804ce74b : skb_copy_and_csum_dev
  18               33.00 - ffffffff804cb740 : sock_alloc_send_skb
  19               31.26 - ffffffff804ce808 : skb_push
  20               22.43 - ffffffff80510004 : tcp_established_options
  21               19.00 - ffffffff8027d250 : find_get_page
  22               15.76 - ffffffff804e4fc9 : eth_type_trans
  23               15.20 - ffffffff804d8baa : dst_release
  24               14.86 - ffffffff804cf5d8 : skb_release_head_state
  25               14.00 - ffffffff802217d5 : read_hpet
  26               12.00 - ffffffff804ffb7f : __ip_local_out
  27               11.97 - ffffffff804fc0c8 : ip_local_deliver_finish
  28                8.54 - ffffffff805001a3 : ip_queue_xmit
  29  */
  30
  31  /*
  32   * Copyright (C) 2008, Red Hat Inc, Ingo Molnar <mingo@redhat.com>
  33   *
  34   * Improvements and fixes by:
  35   *
  36   *   Arjan van de Ven <arjan@linux.intel.com>
  37   *   Yanmin Zhang <yanmin.zhang@intel.com>
  38   *   Wu Fengguang <fengguang.wu@intel.com>
  39   *   Mike Galbraith <efault@gmx.de>
  40   *   Paul Mackerras <paulus@samba.org>
  41   *
  42   * Released under the GPL v2. (and only v2, not any later version)
  43   */
  44
  45
  46 #include "perf.h"
  47 #include "util/util.h"
  48 #include "util/util.h"
  49 #include "util/parse-options.h"
  50 #include "util/parse-events.h"
  51
  52 #include <assert.h>
  53 #include <fcntl.h>
  54
  55 #include <stdio.h>
  56
  57 #include <errno.h>
  58 #include <time.h>
  59 #include <sched.h>
  60 #include <pthread.h>
  61
  62 #include <sys/syscall.h>
  63 #include <sys/ioctl.h>
  64 #include <sys/poll.h>
  65 #include <sys/prctl.h>
  66 #include <sys/wait.h>
  67 #include <sys/uio.h>
  68 #include <sys/mman.h>
  69
  70 #include <linux/unistd.h>
  71 #include <linux/types.h>
  72
  73 static int                      system_wide                     =  0;
  74
  75 static __u64                    default_event_id[MAX_COUNTERS]          = {
  76         EID(PERF_TYPE_SOFTWARE, PERF_COUNT_TASK_CLOCK),
  77         EID(PERF_TYPE_SOFTWARE, PERF_COUNT_CONTEXT_SWITCHES),
  78         EID(PERF_TYPE_SOFTWARE, PERF_COUNT_CPU_MIGRATIONS),
  79         EID(PERF_TYPE_SOFTWARE, PERF_COUNT_PAGE_FAULTS),
  80
  81         EID(PERF_TYPE_HARDWARE, PERF_COUNT_CPU_CYCLES),
  82         EID(PERF_TYPE_HARDWARE, PERF_COUNT_INSTRUCTIONS),
  83         EID(PERF_TYPE_HARDWARE, PERF_COUNT_CACHE_REFERENCES),
  84         EID(PERF_TYPE_HARDWARE, PERF_COUNT_CACHE_MISSES),
  85 };
  86 static int                      default_interval = 100000;
  87 static int                      event_count[MAX_COUNTERS];
  88 static int                      fd[MAX_NR_CPUS][MAX_COUNTERS];
  89
  90 static __u64                    count_filter                   = 100;
  91
  92 static int                      target_pid                              = -1;
  93 static int                      profile_cpu                     = -1;
  94 static int                      nr_cpus                         =  0;
  95 static int                      nmi                             =  1;
  96 static unsigned int             realtime_prio                   =  0;
  97 static int                      group                           =  0;
  98 static unsigned int             page_size;
  99 static unsigned int             mmap_pages                      =  16;
 100 static int                      use_mmap                        = 0;
 101 static int                      use_munmap                      = 0;
 102 static int                      freq                            = 0;
 103
 104 static char                     *sym_filter;
 105 static unsigned long            filter_start;
 106 static unsigned long            filter_end;
 107
 108 static int                      delay_secs                      =  2;
 109 static int                      zero;
 110 static int                      dump_symtab;
 111
 112 static const unsigned int default_count[] = {
 113         1000000,
 114         1000000,
 115           10000,
 116           10000,
 117         1000000,
 118           10000,
 119 };
 120
 121 /*
 122  * Symbols
 123  */
 124
 125 static uint64_t                 min_ip;
 126 static uint64_t                 max_ip = -1ll;
 127
 128 struct sym_entry {
 129         unsigned long long      addr;
 130         char                    *sym;
 131         unsigned long           count[MAX_COUNTERS];
 132         int                     skip;
 133 };
 134
 135 #define MAX_SYMS                100000
 136
 137 static int sym_table_count;
 138
 139 struct sym_entry                *sym_filter_entry;
 140
 141 static struct sym_entry         sym_table[MAX_SYMS];
 142
 143 /*
 144  * Ordering weight: count-1 * count-2 * ... / count-n
 145  */
 146 static double sym_weight(const struct sym_entry *sym)
 147 {
 148         double weight;
 149         int counter;
 150
 151         weight = sym->count[0];
 152
 153         for (counter = 1; counter < nr_counters-1; counter++)
 154                 weight *= sym->count[counter];
 155
 156         weight /= (sym->count[counter] + 1);
 157
 158         return weight;
 159 }
 160
 161 static int compare(const void *__sym1, const void *__sym2)
 162 {
 163         const struct sym_entry *sym1 = __sym1, *sym2 = __sym2;
 164
 165         return sym_weight(sym1) < sym_weight(sym2);
 166 }
 167
 168 static long                     events;
 169 static long                     userspace_events;
 170 static const char               CONSOLE_CLEAR[] = "\e[H\e[2J";
 171
 172 static struct sym_entry         tmp[MAX_SYMS];
 173
 174 static void print_sym_table(void)
 175 {
 176         int i, j, active_count, printed;
 177         int counter;
 178         float events_per_sec = events/delay_secs;
 179         float kevents_per_sec = (events-userspace_events)/delay_secs;
 180         float sum_kevents = 0.0;
 181
 182         events = userspace_events = 0;
 183
 184         /* Iterate over symbol table and copy/tally/decay active symbols. */
 185         for (i = 0, active_count = 0; i < sym_table_count; i++) {
 186                 if (sym_table[i].count[0]) {
 187                         tmp[active_count++] = sym_table[i];
 188                         sum_kevents += sym_table[i].count[0];
 189
 190                         for (j = 0; j < nr_counters; j++)
 191                                 sym_table[i].count[j] = zero ? 0 : sym_table[i].count[j] * 7 / 8;
 192                 }
 193         }
 194
 195         qsort(tmp, active_count + 1, sizeof(tmp[0]), compare);
 196
 197         write(1, CONSOLE_CLEAR, strlen(CONSOLE_CLEAR));
 198
 199         printf(
 200 "------------------------------------------------------------------------------\n");
 201         printf( " KernelTop:%8.0f irqs/sec  kernel:%4.1f%% [%s, ",
 202                 events_per_sec,
 203                 100.0 - (100.0*((events_per_sec-kevents_per_sec)/events_per_sec)),
 204                 nmi ? "NMI" : "IRQ");
 205
 206         if (nr_counters == 1)
 207                 printf("%d ", event_count[0]);
 208
 209         for (counter = 0; counter < nr_counters; counter++) {
 210                 if (counter)
 211                         printf("/");
 212
 213                 printf("%s", event_name(counter));
 214         }
 215
 216         printf( "], ");
 217
 218         if (target_pid != -1)
 219                 printf(" (target_pid: %d", target_pid);
 220         else
 221                 printf(" (all");
 222
 223         if (profile_cpu != -1)
 224                 printf(", cpu: %d)\n", profile_cpu);
 225         else {
 226                 if (target_pid != -1)
 227                         printf(")\n");
 228                 else
 229                         printf(", %d CPUs)\n", nr_cpus);
 230         }
 231
 232         printf("------------------------------------------------------------------------------\n\n");
 233
 234         if (nr_counters == 1)
 235                 printf("             events    pcnt");
 236         else
 237                 printf("  weight     events    pcnt");
 238
 239         printf("         RIP          kernel function\n"
 240                        "  ______     ______   _____   ________________   _______________\n\n"
 241         );
 242
 243         for (i = 0, printed = 0; i < active_count; i++) {
 244                 float pcnt;
 245
 246                 if (++printed > 18 || tmp[i].count[0] < count_filter)
 247                         break;
 248
 249                 pcnt = 100.0 - (100.0*((sum_kevents-tmp[i].count[0])/sum_kevents));
 250
 251                 if (nr_counters == 1)
 252                         printf("%19.2f - %4.1f%% - %016llx : %s\n",
 253                                 sym_weight(tmp + i),
 254                                 pcnt, tmp[i].addr, tmp[i].sym);
 255                 else
 256                         printf("%8.1f %10ld - %4.1f%% - %016llx : %s\n",
 257                                 sym_weight(tmp + i),
 258                                 tmp[i].count[0],
 259                                 pcnt, tmp[i].addr, tmp[i].sym);
 260         }
 261
 262         {
 263                 struct pollfd stdin_poll = { .fd = 0, .events = POLLIN };
 264
 265                 if (poll(&stdin_poll, 1, 0) == 1) {
 266                         printf("key pressed - exiting.\n");
 267                         exit(0);
 268                 }
 269         }
 270 }
 271
 272 static void *display_thread(void *arg)
 273 {
 274         printf("KernelTop refresh period: %d seconds\n", delay_secs);
 275
 276         while (!sleep(delay_secs))
 277                 print_sym_table();
 278
 279         return NULL;
 280 }
 281
 282 static int read_symbol(FILE *in, struct sym_entry *s)
 283 {
 284         static int filter_match = 0;
 285         char *sym, stype;
 286         char str[500];
 287         int rc, pos;
 288
 289         rc = fscanf(in, "%llx %c %499s", &s->addr, &stype, str);
 290         if (rc == EOF)
 291                 return -1;
 292
 293         assert(rc == 3);
 294
 295         /* skip until end of line: */
 296         pos = strlen(str);
 297         do {
 298                 rc = fgetc(in);
 299                 if (rc == '\n' || rc == EOF || pos >= 499)
 300                         break;
 301                 str[pos] = rc;
 302                 pos++;
 303         } while (1);
 304         str[pos] = 0;
 305
 306         sym = str;
 307
 308         /* Filter out known duplicates and non-text symbols. */
 309         if (!strcmp(sym, "_text"))
 310                 return 1;
 311         if (!min_ip && !strcmp(sym, "_stext"))
 312                 return 1;
 313         if (!strcmp(sym, "_etext") || !strcmp(sym, "_sinittext"))
 314                 return 1;
 315         if (stype != 'T' && stype != 't')
 316                 return 1;
 317         if (!strncmp("init_module", sym, 11) || !strncmp("cleanup_module", sym, 14))
 318                 return 1;
 319         if (strstr(sym, "_text_start") || strstr(sym, "_text_end"))
 320                 return 1;
 321
 322         s->sym = malloc(strlen(str)+1);
 323         assert(s->sym);
 324
 325         strcpy((char *)s->sym, str);
 326         s->skip = 0;
 327
 328         /* Tag events to be skipped. */
 329         if (!strcmp("default_idle", s->sym) || !strcmp("cpu_idle", s->sym))
 330                 s->skip = 1;
 331         else if (!strcmp("enter_idle", s->sym) || !strcmp("exit_idle", s->sym))
 332                 s->skip = 1;
 333         else if (!strcmp("mwait_idle", s->sym))
 334                 s->skip = 1;
 335
 336         if (filter_match == 1) {
 337                 filter_end = s->addr;
 338                 filter_match = -1;
 339                 if (filter_end - filter_start > 10000) {
 340                         printf("hm, too large filter symbol <%s> - skipping.\n",
 341                                 sym_filter);
 342                         printf("symbol filter start: %016lx\n", filter_start);
 343                         printf("                end: %016lx\n", filter_end);
 344                         filter_end = filter_start = 0;
 345                         sym_filter = NULL;
 346                         sleep(1);
 347                 }
 348         }
 349         if (filter_match == 0 && sym_filter && !strcmp(s->sym, sym_filter)) {
 350                 filter_match = 1;
 351                 filter_start = s->addr;
 352         }
 353
 354         return 0;
 355 }
 356
 357 static int compare_addr(const void *__sym1, const void *__sym2)
 358 {
 359         const struct sym_entry *sym1 = __sym1, *sym2 = __sym2;
 360
 361         return sym1->addr > sym2->addr;
 362 }
 363
 364 static void sort_symbol_table(void)
 365 {
 366         int i, dups;
 367
 368         do {
 369                 qsort(sym_table, sym_table_count, sizeof(sym_table[0]), compare_addr);
 370                 for (i = 0, dups = 0; i < sym_table_count; i++) {
 371                         if (sym_table[i].addr == sym_table[i+1].addr) {
 372                                 sym_table[i+1].addr = -1ll;
 373                                 dups++;
 374                         }
 375                 }
 376                 sym_table_count -= dups;
 377         } while(dups);
 378 }
 379
 380 static void parse_symbols(void)
 381 {
 382         struct sym_entry *last;
 383
 384         FILE *kallsyms = fopen("/proc/kallsyms", "r");
 385
 386         if (!kallsyms) {
 387                 printf("Could not open /proc/kallsyms - no CONFIG_KALLSYMS_ALL=y?\n");
 388                 exit(-1);
 389         }
 390
 391         while (!feof(kallsyms)) {
 392                 if (read_symbol(kallsyms, &sym_table[sym_table_count]) == 0) {
 393                         sym_table_count++;
 394                         assert(sym_table_count <= MAX_SYMS);
 395                 }
 396         }
 397
 398         sort_symbol_table();
 399         min_ip = sym_table[0].addr;
 400         max_ip = sym_table[sym_table_count-1].addr;
 401         last = sym_table + sym_table_count++;
 402
 403         last->addr = -1ll;
 404         last->sym = "<end>";
 405
 406         if (filter_end) {
 407                 int count;
 408                 for (count=0; count < sym_table_count; count ++) {
 409                         if (!strcmp(sym_table[count].sym, sym_filter)) {
 410                                 sym_filter_entry = &sym_table[count];
 411                                 break;
 412                         }
 413                 }
 414         }
 415         if (dump_symtab) {
 416                 int i;
 417
 418                 for (i = 0; i < sym_table_count; i++)
 419                         fprintf(stderr, "%llx %s\n",
 420                                 sym_table[i].addr, sym_table[i].sym);
 421         }
 422 }
 423
 424 #define TRACE_COUNT     3
 425
 426 /*
 427  * Binary search in the histogram table and record the hit:
 428  */
 429 static void record_ip(uint64_t ip, int counter)
 430 {
 431         int left_idx, middle_idx, right_idx, idx;
 432         unsigned long left, middle, right;
 433
 434         left_idx = 0;
 435         right_idx = sym_table_count-1;
 436         assert(ip <= max_ip && ip >= min_ip);
 437
 438         while (left_idx + 1 < right_idx) {
 439                 middle_idx = (left_idx + right_idx) / 2;
 440
 441                 left   = sym_table[  left_idx].addr;
 442                 middle = sym_table[middle_idx].addr;
 443                 right  = sym_table[ right_idx].addr;
 444
 445                 if (!(left <= middle && middle <= right)) {
 446                         printf("%016lx...\n%016lx...\n%016lx\n", left, middle, right);
 447                         printf("%d %d %d\n", left_idx, middle_idx, right_idx);
 448                 }
 449                 assert(left <= middle && middle <= right);
 450                 if (!(left <= ip && ip <= right)) {
 451                         printf(" left: %016lx\n", left);
 452                         printf("   ip: %016lx\n", (unsigned long)ip);
 453                         printf("right: %016lx\n", right);
 454                 }
 455                 assert(left <= ip && ip <= right);
 456                 /*
 457                  * [ left .... target .... middle .... right ]
 458                  *   => right := middle
 459                  */
 460                 if (ip < middle) {
 461                         right_idx = middle_idx;
 462                         continue;
 463                 }
 464                 /*
 465                  * [ left .... middle ... target ... right ]
 466                  *   => left := middle
 467                  */
 468                 left_idx = middle_idx;
 469         }
 470
 471         idx = left_idx;
 472
 473         if (!sym_table[idx].skip)
 474                 sym_table[idx].count[counter]++;
 475         else events--;
 476 }
 477
 478 static void process_event(uint64_t ip, int counter)
 479 {
 480         events++;
 481
 482         if (ip < min_ip || ip > max_ip) {
 483                 userspace_events++;
 484                 return;
 485         }
 486
 487         record_ip(ip, counter);
 488 }
 489
 490 struct mmap_data {
 491         int counter;
 492         void *base;
 493         unsigned int mask;
 494         unsigned int prev;
 495 };
 496
 497 static unsigned int mmap_read_head(struct mmap_data *md)
 498 {
 499         struct perf_counter_mmap_page *pc = md->base;
 500         int head;
 501
 502         head = pc->data_head;
 503         rmb();
 504
 505         return head;
 506 }
 507
 508 struct timeval last_read, this_read;
 509
 510 static void mmap_read(struct mmap_data *md)
 511 {
 512         unsigned int head = mmap_read_head(md);
 513         unsigned int old = md->prev;
 514         unsigned char *data = md->base + page_size;
 515         int diff;
 516
 517         gettimeofday(&this_read, NULL);
 518
 519         /*
 520          * If we're further behind than half the buffer, there's a chance
 521          * the writer will bite our tail and screw up the events under us.
 522          *
 523          * If we somehow ended up ahead of the head, we got messed up.
 524          *
 525          * In either case, truncate and restart at head.
 526          */
 527         diff = head - old;
 528         if (diff > md->mask / 2 || diff < 0) {
 529                 struct timeval iv;
 530                 unsigned long msecs;
 531
 532                 timersub(&this_read, &last_read, &iv);
 533                 msecs = iv.tv_sec*1000 + iv.tv_usec/1000;
 534
 535                 fprintf(stderr, "WARNING: failed to keep up with mmap data."
 536                                 "  Last read %lu msecs ago.\n", msecs);
 537
 538                 /*
 539                  * head points to a known good entry, start there.
 540                  */
 541                 old = head;
 542         }
 543
 544         last_read = this_read;
 545
 546         for (; old != head;) {
 547                 struct ip_event {
 548                         struct perf_event_header header;
 549                         __u64 ip;
 550                         __u32 pid, target_pid;
 551                 };
 552                 struct mmap_event {
 553                         struct perf_event_header header;
 554                         __u32 pid, target_pid;
 555                         __u64 start;
 556                         __u64 len;
 557                         __u64 pgoff;
 558                         char filename[PATH_MAX];
 559                 };
 560
 561                 typedef union event_union {
 562                         struct perf_event_header header;
 563                         struct ip_event ip;
 564                         struct mmap_event mmap;
 565                 } event_t;
 566
 567                 event_t *event = (event_t *)&data[old & md->mask];
 568
 569                 event_t event_copy;
 570
 571                 size_t size = event->header.size;
 572
 573                 /*
 574                  * Event straddles the mmap boundary -- header should always
 575                  * be inside due to u64 alignment of output.
 576                  */
 577                 if ((old & md->mask) + size != ((old + size) & md->mask)) {
 578                         unsigned int offset = old;
 579                         unsigned int len = min(sizeof(*event), size), cpy;
 580                         void *dst = &event_copy;
 581
 582                         do {
 583                                 cpy = min(md->mask + 1 - (offset & md->mask), len);
 584                                 memcpy(dst, &data[offset & md->mask], cpy);
 585                                 offset += cpy;
 586                                 dst += cpy;
 587                                 len -= cpy;
 588                         } while (len);
 589
 590                         event = &event_copy;
 591                 }
 592
 593                 old += size;
 594
 595                 if (event->header.misc & PERF_EVENT_MISC_OVERFLOW) {
 596                         if (event->header.type & PERF_RECORD_IP)
 597                                 process_event(event->ip.ip, md->counter);
 598                 } else {
 599                         switch (event->header.type) {
 600                                 case PERF_EVENT_MMAP:
 601                                 case PERF_EVENT_MUNMAP:
 602                                         printf("%s: %Lu %Lu %Lu %s\n",
 603                                                         event->header.type == PERF_EVENT_MMAP
 604                                                         ? "mmap" : "munmap",
 605                                                         event->mmap.start,
 606                                                         event->mmap.len,
 607                                                         event->mmap.pgoff,
 608                                                         event->mmap.filename);
 609                                         break;
 610                         }
 611                 }
 612         }
 613
 614         md->prev = old;
 615 }
 616
 617 static struct pollfd event_array[MAX_NR_CPUS * MAX_COUNTERS];
 618 static struct mmap_data mmap_array[MAX_NR_CPUS][MAX_COUNTERS];
 619
 620 static int __cmd_top(void)
 621 {
 622         struct perf_counter_hw_event hw_event;
 623         pthread_t thread;
 624         int i, counter, group_fd, nr_poll = 0;
 625         unsigned int cpu;
 626         int ret;
 627
 628         for (i = 0; i < nr_cpus; i++) {
 629                 group_fd = -1;
 630                 for (counter = 0; counter < nr_counters; counter++) {
 631
 632                         cpu     = profile_cpu;
 633                         if (target_pid == -1 && profile_cpu == -1)
 634                                 cpu = i;
 635
 636                         memset(&hw_event, 0, sizeof(hw_event));
 637                         hw_event.config         = event_id[counter];
 638                         hw_event.irq_period     = event_count[counter];
 639                         hw_event.record_type    = PERF_RECORD_IP | PERF_RECORD_TID;
 640                         hw_event.nmi            = nmi;
 641                         hw_event.mmap           = use_mmap;
 642                         hw_event.munmap         = use_munmap;
 643                         hw_event.freq           = freq;
 644
 645                         fd[i][counter] = sys_perf_counter_open(&hw_event, target_pid, cpu, group_fd, 0);
 646                         if (fd[i][counter] < 0) {
 647                                 int err = errno;
 648                                 printf("kerneltop error: syscall returned with %d (%s)\n",
 649                                         fd[i][counter], strerror(err));
 650                                 if (err == EPERM)
 651                                         printf("Are you root?\n");
 652                                 exit(-1);
 653                         }
 654                         assert(fd[i][counter] >= 0);
 655                         fcntl(fd[i][counter], F_SETFL, O_NONBLOCK);
 656
 657                         /*
 658                          * First counter acts as the group leader:
 659                          */
 660                         if (group && group_fd == -1)
 661                                 group_fd = fd[i][counter];
 662
 663                         event_array[nr_poll].fd = fd[i][counter];
 664                         event_array[nr_poll].events = POLLIN;
 665                         nr_poll++;
 666
 667                         mmap_array[i][counter].counter = counter;
 668                         mmap_array[i][counter].prev = 0;
 669                         mmap_array[i][counter].mask = mmap_pages*page_size - 1;
 670                         mmap_array[i][counter].base = mmap(NULL, (mmap_pages+1)*page_size,
 671                                         PROT_READ, MAP_SHARED, fd[i][counter], 0);
 672                         if (mmap_array[i][counter].base == MAP_FAILED) {
 673                                 printf("kerneltop error: failed to mmap with %d (%s)\n",
 674                                                 errno, strerror(errno));
 675                                 exit(-1);
 676                         }
 677                 }
 678         }
 679
 680         if (pthread_create(&thread, NULL, display_thread, NULL)) {
 681                 printf("Could not create display thread.\n");
 682                 exit(-1);
 683         }
 684
 685         if (realtime_prio) {
 686                 struct sched_param param;
 687
 688                 param.sched_priority = realtime_prio;
 689                 if (sched_setscheduler(0, SCHED_FIFO, &param)) {
 690                         printf("Could not set realtime priority.\n");
 691                         exit(-1);
 692                 }
 693         }
 694
 695         while (1) {
 696                 int hits = events;
 697
 698                 for (i = 0; i < nr_cpus; i++) {
 699                         for (counter = 0; counter < nr_counters; counter++)
 700                                 mmap_read(&mmap_array[i][counter]);
 701                 }
 702
 703                 if (hits == events)
 704                         ret = poll(event_array, nr_poll, 100);
 705         }
 706
 707         return 0;
 708 }
 709
 710 static const char * const top_usage[] = {
 711         "perf top [<options>]",
 712         NULL
 713 };
 714
 715 static char events_help_msg[EVENTS_HELP_MAX];
 716
 717 static const struct option options[] = {
 718         OPT_CALLBACK('e', "event", NULL, "event",
 719                      events_help_msg, parse_events),
 720         OPT_INTEGER('c', "count", &default_interval,
 721                     "event period to sample"),
 722         OPT_INTEGER('p', "pid", &target_pid,
 723                     "profile events on existing pid"),
 724         OPT_BOOLEAN('a', "all-cpus", &system_wide,
 725                             "system-wide collection from all CPUs"),
 726         OPT_INTEGER('C', "CPU", &profile_cpu,
 727                     "CPU to profile on"),
 728         OPT_INTEGER('m', "mmap-pages", &mmap_pages,
 729                     "number of mmap data pages"),
 730         OPT_INTEGER('r', "realtime", &realtime_prio,
 731                     "collect data with this RT SCHED_FIFO priority"),
 732         OPT_INTEGER('d', "delay", &realtime_prio,
 733                     "number of seconds to delay between refreshes"),
 734         OPT_BOOLEAN('D', "dump-symtab", &dump_symtab,
 735                             "dump the symbol table used for profiling"),
 736         OPT_INTEGER('f', "--count-filter", &count_filter,
 737                     "only display functions with more events than this"),
 738         OPT_BOOLEAN('g', "group", &group,
 739                             "put the counters into a counter group"),
 740         OPT_STRING('s', "sym-filter", &sym_filter, "pattern",
 741                     "only display symbols matchig this pattern"),
 742         OPT_BOOLEAN('z', "zero", &group,
 743                     "zero history across updates"),
 744         OPT_BOOLEAN('M', "use-mmap", &use_mmap,
 745                     "track mmap events"),
 746         OPT_BOOLEAN('U', "use-munmap", &use_munmap,
 747                     "track munmap events"),
 748         OPT_INTEGER('F', "--freq", &freq,
 749                     "profile at this frequency"),
 750         OPT_END()
 751 };
 752
 753 int cmd_top(int argc, const char **argv, const char *prefix)
 754 {
 755         int counter;
 756
 757         page_size = sysconf(_SC_PAGE_SIZE);
 758
 759         create_events_help(events_help_msg);
 760         memcpy(event_id, default_event_id, sizeof(default_event_id));
 761
 762         argc = parse_options(argc, argv, options, top_usage, 0);
 763         if (argc)
 764                 usage_with_options(top_usage, options);
 765
 766         if (freq) {
 767                 default_interval = freq;
 768                 freq = 1;
 769         }
 770
 771         /* CPU and PID are mutually exclusive */
 772         if (target_pid != -1 && profile_cpu != -1) {
 773                 printf("WARNING: PID switch overriding CPU\n");
 774                 sleep(1);
 775                 profile_cpu = -1;
 776         }
 777
 778         if (!nr_counters) {
 779                 nr_counters = 1;
 780                 event_id[0] = 0;
 781         }
 782
 783         for (counter = 0; counter < nr_counters; counter++) {
 784                 if (event_count[counter])
 785                         continue;
 786
 787                 event_count[counter] = default_interval;
 788         }
 789
 790         nr_cpus = sysconf(_SC_NPROCESSORS_ONLN);
 791         assert(nr_cpus <= MAX_NR_CPUS);
 792         assert(nr_cpus >= 0);
 793
 794         if (target_pid != -1 || profile_cpu != -1)
 795                 nr_cpus = 1;
 796
 797         parse_symbols();
 798
 799         return __cmd_top();
 800 }