perf_counter: Fix race in counter initialization
[linux-2.6-block.git] / Documentation / perf_counter / builtin-top.c
CommitLineData
07800601 1/*
bf9e1876
IM
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)
07800601 18 */
bf9e1876 19#include "builtin.h"
07800601 20
1a482f38 21#include "perf.h"
bf9e1876 22
de04687f 23#include "util/symbol.h"
148be2c1 24#include "util/util.h"
de04687f 25#include "util/rbtree.h"
b456bae0
IM
26#include "util/parse-options.h"
27#include "util/parse-events.h"
07800601 28
07800601
IM
29#include <assert.h>
30#include <fcntl.h>
0e9b20b8 31
07800601 32#include <stdio.h>
0e9b20b8 33
07800601 34#include <errno.h>
07800601
IM
35#include <time.h>
36#include <sched.h>
37#include <pthread.h>
38
39#include <sys/syscall.h>
40#include <sys/ioctl.h>
41#include <sys/poll.h>
42#include <sys/prctl.h>
43#include <sys/wait.h>
44#include <sys/uio.h>
45#include <sys/mman.h>
46
47#include <linux/unistd.h>
48#include <linux/types.h>
49
07800601
IM
50static int system_wide = 0;
51
b456bae0 52static __u64 default_event_id[MAX_COUNTERS] = {
07800601
IM
53 EID(PERF_TYPE_SOFTWARE, PERF_COUNT_TASK_CLOCK),
54 EID(PERF_TYPE_SOFTWARE, PERF_COUNT_CONTEXT_SWITCHES),
55 EID(PERF_TYPE_SOFTWARE, PERF_COUNT_CPU_MIGRATIONS),
56 EID(PERF_TYPE_SOFTWARE, PERF_COUNT_PAGE_FAULTS),
57
58 EID(PERF_TYPE_HARDWARE, PERF_COUNT_CPU_CYCLES),
59 EID(PERF_TYPE_HARDWARE, PERF_COUNT_INSTRUCTIONS),
60 EID(PERF_TYPE_HARDWARE, PERF_COUNT_CACHE_REFERENCES),
61 EID(PERF_TYPE_HARDWARE, PERF_COUNT_CACHE_MISSES),
62};
63static int default_interval = 100000;
64static int event_count[MAX_COUNTERS];
65static int fd[MAX_NR_CPUS][MAX_COUNTERS];
66
67static __u64 count_filter = 100;
68
b456bae0 69static int target_pid = -1;
07800601
IM
70static int profile_cpu = -1;
71static int nr_cpus = 0;
07800601
IM
72static unsigned int realtime_prio = 0;
73static int group = 0;
74static unsigned int page_size;
75static unsigned int mmap_pages = 16;
76static int use_mmap = 0;
77static int use_munmap = 0;
f5456a6b 78static int freq = 0;
07800601 79
07800601
IM
80static char *sym_filter;
81static unsigned long filter_start;
82static unsigned long filter_end;
83
84static int delay_secs = 2;
85static int zero;
86static int dump_symtab;
87
ddcacfa0 88static const unsigned int default_count[] = {
07800601
IM
89 1000000,
90 1000000,
91 10000,
92 10000,
93 1000000,
94 10000,
95};
96
07800601
IM
97/*
98 * Symbols
99 */
100
101static uint64_t min_ip;
102static uint64_t max_ip = -1ll;
103
104struct sym_entry {
de04687f
ACM
105 struct rb_node rb_node;
106 struct list_head node;
07800601 107 unsigned long count[MAX_COUNTERS];
c44613a4
ACM
108 unsigned long snap_count;
109 double weight;
07800601 110 int skip;
07800601
IM
111};
112
07800601
IM
113struct sym_entry *sym_filter_entry;
114
de04687f
ACM
115struct dso *kernel_dso;
116
117/*
118 * Symbols will be added here in record_ip and will get out
119 * after decayed.
120 */
121static LIST_HEAD(active_symbols);
c44613a4 122static pthread_mutex_t active_symbols_lock = PTHREAD_MUTEX_INITIALIZER;
07800601 123
07800601
IM
124/*
125 * Ordering weight: count-1 * count-2 * ... / count-n
126 */
127static double sym_weight(const struct sym_entry *sym)
128{
c44613a4 129 double weight = sym->snap_count;
07800601
IM
130 int counter;
131
07800601
IM
132 for (counter = 1; counter < nr_counters-1; counter++)
133 weight *= sym->count[counter];
134
135 weight /= (sym->count[counter] + 1);
136
137 return weight;
138}
139
07800601
IM
140static long events;
141static long userspace_events;
142static const char CONSOLE_CLEAR[] = "\e[H\e[2J";
143
c44613a4 144static void __list_insert_active_sym(struct sym_entry *syme)
de04687f
ACM
145{
146 list_add(&syme->node, &active_symbols);
147}
148
c44613a4
ACM
149static void list_remove_active_sym(struct sym_entry *syme)
150{
151 pthread_mutex_lock(&active_symbols_lock);
152 list_del_init(&syme->node);
153 pthread_mutex_unlock(&active_symbols_lock);
154}
155
de04687f
ACM
156static void rb_insert_active_sym(struct rb_root *tree, struct sym_entry *se)
157{
158 struct rb_node **p = &tree->rb_node;
159 struct rb_node *parent = NULL;
160 struct sym_entry *iter;
161
162 while (*p != NULL) {
163 parent = *p;
164 iter = rb_entry(parent, struct sym_entry, rb_node);
165
c44613a4 166 if (se->weight > iter->weight)
de04687f
ACM
167 p = &(*p)->rb_left;
168 else
169 p = &(*p)->rb_right;
170 }
171
172 rb_link_node(&se->rb_node, parent, p);
173 rb_insert_color(&se->rb_node, tree);
174}
07800601
IM
175
176static void print_sym_table(void)
177{
de04687f 178 int printed, j;
07800601
IM
179 int counter;
180 float events_per_sec = events/delay_secs;
181 float kevents_per_sec = (events-userspace_events)/delay_secs;
182 float sum_kevents = 0.0;
de04687f
ACM
183 struct sym_entry *syme, *n;
184 struct rb_root tmp = RB_ROOT;
185 struct rb_node *nd;
07800601
IM
186
187 events = userspace_events = 0;
07800601 188
de04687f 189 /* Sort the active symbols */
c44613a4
ACM
190 pthread_mutex_lock(&active_symbols_lock);
191 syme = list_entry(active_symbols.next, struct sym_entry, node);
192 pthread_mutex_unlock(&active_symbols_lock);
193
194 list_for_each_entry_safe_from(syme, n, &active_symbols, node) {
195 syme->snap_count = syme->count[0];
196 if (syme->snap_count != 0) {
197 syme->weight = sym_weight(syme);
de04687f 198 rb_insert_active_sym(&tmp, syme);
c44613a4 199 sum_kevents += syme->snap_count;
d94b9430
MG
200
201 for (j = 0; j < nr_counters; j++)
de04687f
ACM
202 syme->count[j] = zero ? 0 : syme->count[j] * 7 / 8;
203 } else
c44613a4 204 list_remove_active_sym(syme);
d94b9430
MG
205 }
206
07800601
IM
207 write(1, CONSOLE_CLEAR, strlen(CONSOLE_CLEAR));
208
209 printf(
210"------------------------------------------------------------------------------\n");
f91183fe 211 printf( " KernelTop:%8.0f irqs/sec kernel:%4.1f%% [",
07800601 212 events_per_sec,
f91183fe 213 100.0 - (100.0*((events_per_sec-kevents_per_sec)/events_per_sec)));
07800601
IM
214
215 if (nr_counters == 1)
216 printf("%d ", event_count[0]);
217
218 for (counter = 0; counter < nr_counters; counter++) {
219 if (counter)
220 printf("/");
221
222 printf("%s", event_name(counter));
223 }
224
225 printf( "], ");
226
b456bae0
IM
227 if (target_pid != -1)
228 printf(" (target_pid: %d", target_pid);
07800601
IM
229 else
230 printf(" (all");
231
232 if (profile_cpu != -1)
233 printf(", cpu: %d)\n", profile_cpu);
234 else {
b456bae0 235 if (target_pid != -1)
07800601
IM
236 printf(")\n");
237 else
238 printf(", %d CPUs)\n", nr_cpus);
239 }
240
241 printf("------------------------------------------------------------------------------\n\n");
242
243 if (nr_counters == 1)
244 printf(" events pcnt");
245 else
246 printf(" weight events pcnt");
247
248 printf(" RIP kernel function\n"
249 " ______ ______ _____ ________________ _______________\n\n"
250 );
251
de04687f
ACM
252 for (nd = rb_first(&tmp); nd; nd = rb_next(nd)) {
253 struct sym_entry *syme = rb_entry(nd, struct sym_entry, rb_node);
254 struct symbol *sym = (struct symbol *)(syme + 1);
07800601 255 float pcnt;
d94b9430 256
c44613a4
ACM
257 if (++printed > 18 || syme->snap_count < count_filter)
258 continue;
d94b9430 259
c44613a4 260 pcnt = 100.0 - (100.0 * ((sum_kevents - syme->snap_count) /
de04687f 261 sum_kevents));
d94b9430
MG
262
263 if (nr_counters == 1)
264 printf("%19.2f - %4.1f%% - %016llx : %s\n",
c44613a4 265 syme->weight, pcnt, sym->start, sym->name);
d94b9430
MG
266 else
267 printf("%8.1f %10ld - %4.1f%% - %016llx : %s\n",
c44613a4 268 syme->weight, syme->snap_count,
de04687f 269 pcnt, sym->start, sym->name);
07800601
IM
270 }
271
07800601
IM
272 {
273 struct pollfd stdin_poll = { .fd = 0, .events = POLLIN };
274
275 if (poll(&stdin_poll, 1, 0) == 1) {
276 printf("key pressed - exiting.\n");
277 exit(0);
278 }
279 }
280}
281
282static void *display_thread(void *arg)
283{
284 printf("KernelTop refresh period: %d seconds\n", delay_secs);
285
286 while (!sleep(delay_secs))
287 print_sym_table();
288
289 return NULL;
290}
291
de04687f 292static int symbol_filter(struct dso *self, struct symbol *sym)
07800601 293{
de04687f
ACM
294 static int filter_match;
295 struct sym_entry *syme;
296 const char *name = sym->name;
297
298 if (!strcmp(name, "_text") ||
299 !strcmp(name, "_etext") ||
300 !strcmp(name, "_sinittext") ||
301 !strncmp("init_module", name, 11) ||
302 !strncmp("cleanup_module", name, 14) ||
303 strstr(name, "_text_start") ||
304 strstr(name, "_text_end"))
07800601 305 return 1;
07800601 306
de04687f 307 syme = dso__sym_priv(self, sym);
07800601 308 /* Tag events to be skipped. */
de04687f
ACM
309 if (!strcmp("default_idle", name) ||
310 !strcmp("cpu_idle", name) ||
311 !strcmp("enter_idle", name) ||
312 !strcmp("exit_idle", name) ||
313 !strcmp("mwait_idle", name))
314 syme->skip = 1;
07800601
IM
315
316 if (filter_match == 1) {
de04687f 317 filter_end = sym->start;
07800601
IM
318 filter_match = -1;
319 if (filter_end - filter_start > 10000) {
de04687f
ACM
320 fprintf(stderr,
321 "hm, too large filter symbol <%s> - skipping.\n",
07800601 322 sym_filter);
de04687f
ACM
323 fprintf(stderr, "symbol filter start: %016lx\n",
324 filter_start);
325 fprintf(stderr, " end: %016lx\n",
326 filter_end);
07800601
IM
327 filter_end = filter_start = 0;
328 sym_filter = NULL;
329 sleep(1);
330 }
331 }
de04687f
ACM
332
333 if (filter_match == 0 && sym_filter && !strcmp(name, sym_filter)) {
07800601 334 filter_match = 1;
de04687f 335 filter_start = sym->start;
07800601
IM
336 }
337
de04687f 338
07800601
IM
339 return 0;
340}
341
de04687f 342static int parse_symbols(void)
07800601 343{
de04687f
ACM
344 struct rb_node *node;
345 struct symbol *sym;
07800601 346
de04687f
ACM
347 kernel_dso = dso__new("[kernel]", sizeof(struct sym_entry));
348 if (kernel_dso == NULL)
349 return -1;
07800601 350
de04687f
ACM
351 if (dso__load_kernel(kernel_dso, NULL, symbol_filter) != 0)
352 goto out_delete_dso;
07800601 353
de04687f
ACM
354 node = rb_first(&kernel_dso->syms);
355 sym = rb_entry(node, struct symbol, rb_node);
356 min_ip = sym->start;
07800601 357
de04687f
ACM
358 node = rb_last(&kernel_dso->syms);
359 sym = rb_entry(node, struct symbol, rb_node);
da417a75 360 max_ip = sym->end;
07800601 361
de04687f 362 if (dump_symtab)
a3ec8d70 363 dso__fprintf(kernel_dso, stderr);
07800601 364
de04687f 365 return 0;
07800601 366
de04687f
ACM
367out_delete_dso:
368 dso__delete(kernel_dso);
369 kernel_dso = NULL;
370 return -1;
07800601
IM
371}
372
07800601
IM
373#define TRACE_COUNT 3
374
07800601
IM
375/*
376 * Binary search in the histogram table and record the hit:
377 */
378static void record_ip(uint64_t ip, int counter)
379{
de04687f 380 struct symbol *sym = dso__find_symbol(kernel_dso, ip);
07800601 381
de04687f
ACM
382 if (sym != NULL) {
383 struct sym_entry *syme = dso__sym_priv(kernel_dso, sym);
07800601 384
de04687f
ACM
385 if (!syme->skip) {
386 syme->count[counter]++;
c44613a4 387 pthread_mutex_lock(&active_symbols_lock);
de04687f 388 if (list_empty(&syme->node) || !syme->node.next)
c44613a4
ACM
389 __list_insert_active_sym(syme);
390 pthread_mutex_unlock(&active_symbols_lock);
de04687f 391 return;
07800601 392 }
07800601
IM
393 }
394
de04687f 395 events--;
07800601
IM
396}
397
398static void process_event(uint64_t ip, int counter)
399{
400 events++;
401
402 if (ip < min_ip || ip > max_ip) {
403 userspace_events++;
404 return;
405 }
406
407 record_ip(ip, counter);
408}
409
07800601
IM
410struct mmap_data {
411 int counter;
412 void *base;
413 unsigned int mask;
414 unsigned int prev;
415};
416
417static unsigned int mmap_read_head(struct mmap_data *md)
418{
419 struct perf_counter_mmap_page *pc = md->base;
420 int head;
421
422 head = pc->data_head;
423 rmb();
424
425 return head;
426}
427
428struct timeval last_read, this_read;
429
430static void mmap_read(struct mmap_data *md)
431{
432 unsigned int head = mmap_read_head(md);
433 unsigned int old = md->prev;
434 unsigned char *data = md->base + page_size;
435 int diff;
436
437 gettimeofday(&this_read, NULL);
438
439 /*
440 * If we're further behind than half the buffer, there's a chance
441 * the writer will bite our tail and screw up the events under us.
442 *
443 * If we somehow ended up ahead of the head, we got messed up.
444 *
445 * In either case, truncate and restart at head.
446 */
447 diff = head - old;
448 if (diff > md->mask / 2 || diff < 0) {
449 struct timeval iv;
450 unsigned long msecs;
451
452 timersub(&this_read, &last_read, &iv);
453 msecs = iv.tv_sec*1000 + iv.tv_usec/1000;
454
455 fprintf(stderr, "WARNING: failed to keep up with mmap data."
456 " Last read %lu msecs ago.\n", msecs);
457
458 /*
459 * head points to a known good entry, start there.
460 */
461 old = head;
462 }
463
464 last_read = this_read;
465
466 for (; old != head;) {
467 struct ip_event {
468 struct perf_event_header header;
469 __u64 ip;
b456bae0 470 __u32 pid, target_pid;
07800601
IM
471 };
472 struct mmap_event {
473 struct perf_event_header header;
b456bae0 474 __u32 pid, target_pid;
07800601
IM
475 __u64 start;
476 __u64 len;
477 __u64 pgoff;
478 char filename[PATH_MAX];
479 };
480
481 typedef union event_union {
482 struct perf_event_header header;
483 struct ip_event ip;
484 struct mmap_event mmap;
485 } event_t;
486
487 event_t *event = (event_t *)&data[old & md->mask];
488
489 event_t event_copy;
490
6f06ccbc 491 size_t size = event->header.size;
07800601
IM
492
493 /*
494 * Event straddles the mmap boundary -- header should always
495 * be inside due to u64 alignment of output.
496 */
497 if ((old & md->mask) + size != ((old + size) & md->mask)) {
498 unsigned int offset = old;
499 unsigned int len = min(sizeof(*event), size), cpy;
500 void *dst = &event_copy;
501
502 do {
503 cpy = min(md->mask + 1 - (offset & md->mask), len);
504 memcpy(dst, &data[offset & md->mask], cpy);
505 offset += cpy;
506 dst += cpy;
507 len -= cpy;
508 } while (len);
509
510 event = &event_copy;
511 }
512
513 old += size;
514
515 if (event->header.misc & PERF_EVENT_MISC_OVERFLOW) {
c70975bc 516 if (event->header.type & PERF_SAMPLE_IP)
07800601
IM
517 process_event(event->ip.ip, md->counter);
518 } else {
519 switch (event->header.type) {
520 case PERF_EVENT_MMAP:
521 case PERF_EVENT_MUNMAP:
522 printf("%s: %Lu %Lu %Lu %s\n",
523 event->header.type == PERF_EVENT_MMAP
524 ? "mmap" : "munmap",
525 event->mmap.start,
526 event->mmap.len,
527 event->mmap.pgoff,
528 event->mmap.filename);
529 break;
530 }
531 }
532 }
533
534 md->prev = old;
535}
536
c2990a2a
MG
537static struct pollfd event_array[MAX_NR_CPUS * MAX_COUNTERS];
538static struct mmap_data mmap_array[MAX_NR_CPUS][MAX_COUNTERS];
539
b456bae0 540static int __cmd_top(void)
07800601 541{
c70975bc 542 struct perf_counter_attr attr;
07800601
IM
543 pthread_t thread;
544 int i, counter, group_fd, nr_poll = 0;
545 unsigned int cpu;
546 int ret;
547
07800601
IM
548 for (i = 0; i < nr_cpus; i++) {
549 group_fd = -1;
550 for (counter = 0; counter < nr_counters; counter++) {
551
552 cpu = profile_cpu;
b456bae0 553 if (target_pid == -1 && profile_cpu == -1)
07800601
IM
554 cpu = i;
555
c70975bc
PZ
556 memset(&attr, 0, sizeof(attr));
557 attr.config = event_id[counter];
558 attr.sample_period = event_count[counter];
559 attr.sample_type = PERF_SAMPLE_IP | PERF_SAMPLE_TID;
560 attr.mmap = use_mmap;
561 attr.munmap = use_munmap;
562 attr.freq = freq;
07800601 563
c70975bc 564 fd[i][counter] = sys_perf_counter_open(&attr, target_pid, cpu, group_fd, 0);
07800601
IM
565 if (fd[i][counter] < 0) {
566 int err = errno;
567 printf("kerneltop error: syscall returned with %d (%s)\n",
568 fd[i][counter], strerror(err));
569 if (err == EPERM)
570 printf("Are you root?\n");
571 exit(-1);
572 }
573 assert(fd[i][counter] >= 0);
574 fcntl(fd[i][counter], F_SETFL, O_NONBLOCK);
575
576 /*
577 * First counter acts as the group leader:
578 */
579 if (group && group_fd == -1)
580 group_fd = fd[i][counter];
581
582 event_array[nr_poll].fd = fd[i][counter];
583 event_array[nr_poll].events = POLLIN;
584 nr_poll++;
585
586 mmap_array[i][counter].counter = counter;
587 mmap_array[i][counter].prev = 0;
588 mmap_array[i][counter].mask = mmap_pages*page_size - 1;
589 mmap_array[i][counter].base = mmap(NULL, (mmap_pages+1)*page_size,
590 PROT_READ, MAP_SHARED, fd[i][counter], 0);
591 if (mmap_array[i][counter].base == MAP_FAILED) {
592 printf("kerneltop error: failed to mmap with %d (%s)\n",
593 errno, strerror(errno));
594 exit(-1);
595 }
596 }
597 }
598
599 if (pthread_create(&thread, NULL, display_thread, NULL)) {
600 printf("Could not create display thread.\n");
601 exit(-1);
602 }
603
604 if (realtime_prio) {
605 struct sched_param param;
606
607 param.sched_priority = realtime_prio;
608 if (sched_setscheduler(0, SCHED_FIFO, &param)) {
609 printf("Could not set realtime priority.\n");
610 exit(-1);
611 }
612 }
613
614 while (1) {
615 int hits = events;
616
617 for (i = 0; i < nr_cpus; i++) {
618 for (counter = 0; counter < nr_counters; counter++)
619 mmap_read(&mmap_array[i][counter]);
620 }
621
622 if (hits == events)
623 ret = poll(event_array, nr_poll, 100);
624 }
625
626 return 0;
627}
b456bae0
IM
628
629static const char * const top_usage[] = {
630 "perf top [<options>]",
631 NULL
632};
633
634static char events_help_msg[EVENTS_HELP_MAX];
635
636static const struct option options[] = {
637 OPT_CALLBACK('e', "event", NULL, "event",
638 events_help_msg, parse_events),
639 OPT_INTEGER('c', "count", &default_interval,
640 "event period to sample"),
641 OPT_INTEGER('p', "pid", &target_pid,
642 "profile events on existing pid"),
643 OPT_BOOLEAN('a', "all-cpus", &system_wide,
644 "system-wide collection from all CPUs"),
645 OPT_INTEGER('C', "CPU", &profile_cpu,
646 "CPU to profile on"),
647 OPT_INTEGER('m', "mmap-pages", &mmap_pages,
648 "number of mmap data pages"),
649 OPT_INTEGER('r', "realtime", &realtime_prio,
650 "collect data with this RT SCHED_FIFO priority"),
db20c003 651 OPT_INTEGER('d', "delay", &delay_secs,
b456bae0
IM
652 "number of seconds to delay between refreshes"),
653 OPT_BOOLEAN('D', "dump-symtab", &dump_symtab,
654 "dump the symbol table used for profiling"),
655 OPT_INTEGER('f', "--count-filter", &count_filter,
656 "only display functions with more events than this"),
657 OPT_BOOLEAN('g', "group", &group,
658 "put the counters into a counter group"),
659 OPT_STRING('s', "sym-filter", &sym_filter, "pattern",
660 "only display symbols matchig this pattern"),
661 OPT_BOOLEAN('z', "zero", &group,
662 "zero history across updates"),
663 OPT_BOOLEAN('M', "use-mmap", &use_mmap,
664 "track mmap events"),
665 OPT_BOOLEAN('U', "use-munmap", &use_munmap,
666 "track munmap events"),
667 OPT_INTEGER('F', "--freq", &freq,
668 "profile at this frequency"),
669 OPT_END()
670};
671
672int cmd_top(int argc, const char **argv, const char *prefix)
673{
674 int counter;
675
676 page_size = sysconf(_SC_PAGE_SIZE);
677
678 create_events_help(events_help_msg);
679 memcpy(event_id, default_event_id, sizeof(default_event_id));
680
681 argc = parse_options(argc, argv, options, top_usage, 0);
682 if (argc)
683 usage_with_options(top_usage, options);
684
685 if (freq) {
686 default_interval = freq;
687 freq = 1;
688 }
689
690 /* CPU and PID are mutually exclusive */
691 if (target_pid != -1 && profile_cpu != -1) {
692 printf("WARNING: PID switch overriding CPU\n");
693 sleep(1);
694 profile_cpu = -1;
695 }
696
697 if (!nr_counters) {
698 nr_counters = 1;
699 event_id[0] = 0;
700 }
701
702 for (counter = 0; counter < nr_counters; counter++) {
703 if (event_count[counter])
704 continue;
705
706 event_count[counter] = default_interval;
707 }
708
709 nr_cpus = sysconf(_SC_NPROCESSORS_ONLN);
710 assert(nr_cpus <= MAX_NR_CPUS);
711 assert(nr_cpus >= 0);
712
713 if (target_pid != -1 || profile_cpu != -1)
714 nr_cpus = 1;
715
716 parse_symbols();
717
718 return __cmd_top();
719}